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Scientia Horticulturae 156 (2013) 73–85

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Scientia Horticulturae

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hysiological and biochemical mechanisms regulating chillingolerance in fruits and vegetables under postharvest salicylatesnd jasmonates treatments

orteza Soleimani Aghdama,∗, Samad Bodbodakb

Young Researchers and Elite Club, Ahar Branch, Islamic Azad University, Ahar, IranDepartment of Food Science and Technology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran

r t i c l e i n f o

rticle history:eceived 15 February 2013eceived in revised form 26 March 2013ccepted 27 March 2013

eywords:ruitsegetablesut flowersalicylatesasmonateshilling injury

a b s t r a c t

Low temperature storage has been the main strategy to increase the shelf life of fruits and vegetables byreducing the rate of respiration and minimizing fungal disease growth. However, tropical and subtropi-cal fruits and vegetables stored below 10–12 ◦C develop chilling injury (CI) following storage beyond theCI threshold. CI as a physiological disorder greatly reduces fruits and vegetables quality and frequentlyrenders the product not saleable. The increasing demand for consumption of fresh fruits and vegetables,along with restriction on the use of synthetic chemicals to reduce CI, has encouraged scientific researchto develop new technologies based on natural product such as salicylates and jasmonates. Membranedamage and reactive oxygen species (ROS) production are multifarious adverse effects of chilling asoxidative stress in sensitive fruits and vegetables. Chilling alleviating in fruits and vegetables treated withsalicylates and jasmonates could be attributed to (1) Enhancing membrane integrity by reducing phos-pholipase D and C (PLD and PLC) and lipoxygenase (LOX) enzymes activities, enhancing unsaturated fattyacids/saturated fatty acids (unSFA/SFA) ratio probably through increase of fatty acid desaturases (FAD)gene expression and maintaining energy status, ATP and adenylate energy charge (AEC). (2) Enhancingheat shock proteins (HSPs) gene expression and accumulation. (3) Enhancing antioxidant system activity.(4) Enhancing arginine pathways which led to accumulation of signaling molecules with pivotal roles in
improving chilling tolerance such as polyamines, nitric oxide, proline and �-aminobutyric acid (GABA).(5) Activation of C-repeat binding factor (CBF) pathway and (6) alteration in phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO) enzymes activities. In the present review, we have focusedon impacts of exogenous salicylates and jasmonates treatments on postharvest chilling tolerance andmechanisms employed by these safe signaling molecules in fruits, vegetables and cut flowers have alsobeen discussed.
© 2013 Elsevier B.V. All rights reserved.

ontents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 742. Chilling injury and its impact on cell membrane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 743. Chilling injury as an oxidative stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 744. Mechanism employed by salicylates and jasmonates for alleviating of chilling injury in fruits, vegetables and cut flowers . . . . . . . . . . . . . . . . . . . . . . 76

4.1. Enhancing membrane integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 764.2. Enhancing antioxidant system activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 764.3. Enhancing HSPs accumulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.4. Enhancing arginine pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.5. Activation of CBF pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.6. Alteration in PAL and PPO enzymes activities . . . . . . . . . . . . . . . . . . . . . .
∗ Corresponding author. Tel.: +98 914 759 8795; fax: +98 426 223 4857.E-mail addresses: [email protected], [email protected] (M.S. Aghdam).

304-4238/$ – see front matter © 2013 Elsevier B.V. All rights reserved.ttp://dx.doi.org/10.1016/j.scienta.2013.03.028

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74 M.S. Aghdam, S. Bodbodak / Scientia Horticulturae 156 (2013) 73–85

5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

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References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. Introduction

In line with consumers’ concerns about residues of chemicalsn fruits and vegetables, applications of safe and environmen-ally friendly technologies to prevent or alleviate CI are of greatmportance and considerable efforts have been invested in thisostharvest research field. The increasing demand for consumptionf fruits and vegetables, along with restriction on the use of syn-hetic chemicals, has encouraged scientific research to develop newechnologies based on natural product such as salicylic acid (SA),cetyl salicylic acid (ASA), methyl salicylate (MeSA) and methyl jas-onate (MeJA). Although there are many methods to reduce CI in

ruits and vegetables, salicylates and jasmonates treatments arenexpensive, easy to apply and can be used on fruits and vegetablesAsghari and Aghdam, 2010).

SA, as natural and safe phenolic molecule, at non-toxic con-entrations may be commercially used in alleviating CI in fruits,egetables and flowers. SA treatment at non-toxic concentrationslleviates postharvest CI in fruits, vegetables and flowers such asomato (Ding et al., 2001, 2002; Fung et al., 2006; Zhang et al., 2011;ghdam et al., 2012a,b), loquat (Cai et al., 2006), peach (Wang et al.,006; Cao et al., 2010; Yang et al., 2012), pomegranate (Sayyarit al., 2009, 2011a,b), pineapple (Lu et al., 2010, 2011), sweet pep-er (Fung et al., 2004), anthurium (Promyou et al., 2012), bamboohoot (Luo et al., 2012) and plum (Luo et al., 2011). Thus SA hasigh commercial potential for use at low concentrations in alle-iating CI in fruits, vegetables and flowers. Also, treatment witheJA at non-toxic concentrations alleviates CI in fruits and veg-

tables such as tomato (Ding et al., 2001, 2002; Fung et al., 2006;hang et al., 2012), loquat (Cao et al., 2009, 2012; Cai et al., 2011),omegranate (Sayyari et al., 2011a,b), banana (Zhao et al., 2012)nd sweet pepper (Fung et al., 2004). Thus, MeJA as a potentialreatment can use commercially for alleviating CI in fruits and veg-tables. The present review discusses the application of postharvestalicylates and jasmonates treatments and their physiological, bio-hemical and molecular mechanisms for CI alleviating of the targetruits, vegetables and cut flowers.

. Chilling injury and its impact on cell membrane

Cell membrane integrity is the primary cell structure affectedy CI (Rui et al., 2010). Transition of cell membranes phase from

flexible liquid-crystalline to a solid-gel structure that occurs athilling temperature increments the risk of loss of controlled cellembrane semi-permeability (Lyons, 1973). At chilling tempera-

ure, membrane fatty acid peroxidation, increase of the saturationegree of these fatty acids, degradation of phospholipids and galac-olipids, and the rise of the sterol to phospholipid ratio lead toeduction of membrane fluidity and performance. If the tissue,rgan or whole plant is exposed to damaging temperatures for tooong a period of time then cell membranes rupture takes place,ausing leakage of intracellular water, ions and metabolites, whichan be monitored by determination of electrolyte leakage (Sharomt al., 1994). Electrolyte leakage is an effective parameter to assessembrane permeability and therefore is used as an indicator ofembrane integrity (Marangoni et al., 1996). Also, lipid peroxida-

ion which is responsible for loss of cell membrane integrity cane evaluated by the malonyl-dialdehyde (MDA) production (Wisend Naylor, 1987). MDA is the end product of the peroxidation ofembrane fatty acids and the level of this compound is used as a

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marker of oxidative stress, since a rise in this compound is indicat-ing damage on cell membrane integrity (Hodges et al., 1999). Theprincipal consequence of both events is the loss of the biomem-brane functionality (Sevillano et al., 2009). In summary, electrolyteleakage and MDA content, well known physiological markers ofloss of membrane semi-permeability and membrane lipid perox-idation, are widely used by researchers to indirectly assess cellmembrane integrity (Wise and Naylor, 1987; Sharom et al., 1994).Through these methodological approaches for evaluating cell mem-branes integrity it is possible to assess the impact of CI in fruits andvegetables in a very precise way (Shewfelt and Purvis, 1995).

FADs are a group of enzymes responsible for the increase ofmembrane unsaturation degree (Hernández et al., 2011). Also,increase of PLD and LOX activities, enzymes that are responsible forthe degradation of unsaturated fatty acids, reduced cell membraneintegrity and therefore augmented the impact of CI (Pinhero et al.,1998) (Fig. 1). Reduction of PLD and LOX activities in cucumberand tomato fruits subjected to heat and SA treatments, respec-tively, led to an increase of CI resistance by means of improving cellmembrane integrity and diminishing lipid peroxidation (Mao et al.,2007a,b; Aghdam et al., 2012a,b). In addition to lipid peroxidation ofunsaturated fatty acids, there are two metabolic energy parametersto be considered, – ATP and AEC – according to their associated rolein biosynthesis of fatty acids and their unsaturation. Reduction ofmetabolic energy levels (decrease of ATP, ADP and AEC and increaseof AMP) can also negatively affect the integrity of cell membranes(Brown and Beevers, 1987; Crawford and Braendle, 1996).

3. Chilling injury as an oxidative stress

Oxidative stress is a common secondary stress occurring indiverse biotic and abiotic stress, and CI is no exception to this rule.We have already mentioned the direct effect of low temperatureson the molecular arrangement of lipids constituting cell mem-branes. The loss of membrane integrity is itself boosted by oxidativeprocesses, since cold stress increases the levels of ROS that stimu-lates lipid peroxidation in cell membranes (Sevillano et al., 2009)(Fig. 1). Moller (2001) suggested that plant defense against oxida-tive stress is accomplished in two ways. The first is by activationof the expression of genes encoding proteins involved in activat-ing ROS avoidance such as alternative oxidase (AOX). The AOXpathway is a branch of the respiratory electron transport chainin mitochondria that emerges from the cytochrome. When over-reduction occurs in this electron transport chain, AOX intervenes byinhibiting the excessive reduction of ubiquinol and thus assists inavoiding ROS accumulation (Moller, 2001) (Fig. 2). This antioxidantactivity of AOX has been reported in pepper and tobacco (Purvis,1997; Maxwell et al., 1999). Increase in the level of AOX geneexpression in pepper fruit treated with MeSA and MeJA enhancedCI tolerance (Fung et al., 2004). Enhancement of AOX gene expres-sion leads to an increase in resistance against CI via maintenance ofthe balance between ROS production and the general antioxidantsystem activity (Purvis, 1997).

The second way of defense against oxidative stress is by induc-ing the activity or the gene expression for ROS scavengers suchas antioxidant enzymes like superoxide dismutase (SOD), cata-
lase (CAT), ascorbate peroxidase (APX), glutathione peroxidase(GPX), glutathione-S-transferase (GST), monodehydroascorbatereductase (MDHAR), dehydroascorbate reductase (DHAR) and glu-tathione reductase (GR) (Moller, 2001). Higher activity of the

M.S. Aghdam, S. Bodbodak / Scientia Horticulturae 156 (2013) 73–85 75

Fig. 1. Alterations in the cell membrane integrity and conformation due to cold stress led to solute leakage and oxidative stress, which could trigger widespread celld sist to

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ecompartmentation and oxidation, and lastly cell death if stressful conditions per

dapted from Lyons (1973) and Marangoni et al. (1996).

nzymatic antioxidant system leads to reduction of ROS, thereforemproving membrane integrity and ultimately inducing resistanceowards abiotic stresses such as CI (Mittler, 2002) (Fig. 2).

Cao et al. (2011) observed that resistance towards CI of chilling-
olerant Qingzhong cultivar of loquat fruit in comparison withhilling-sensitive Fuyang cultivar was associated with a higher con-ent of linolenic and linoleic acids, characteristic unSFA, and lower
Fig. 2. Schematic view of the antioxidant systems that plant cells display in orde

o long.

levels of palmitic and stearic acid, characteristic SFA, with bothevents yielding a higher unSFA/SFA ratio. Higher SOD and CAT activ-ities along with lower LOX activity led to alleviating of oxidativestress due to a decrease of H2O2 and O2-contents. The authors also
observed that APX, GR and MDHAR activities in Qingzhong werehigher than in Fuyang loquat cultivar, which generated an increaseof ascorbic acid (AA) and glutathione (GSH) levels, boosting AA/DHA
r to counteract oxidative stress, based on Moller (2001) and Mittler (2002).

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nd GSH/GSSG ratios. Thus, high resistance of Qingzhong towardsI could be attributed to (i) a higher unSFA/SFA ratio, and (ii) aigher ROS-scavenging enzymes activity accompanied by a lowerOX activity. This scenario is mainly responsible for the higher tol-rance towards CI in Qingzhong cultivar (Cao et al., 2011).

In summary, it can be concluded that a high ratio of unSFA/SFA,igh levels of cell metabolic energy (ATP and AEC), and a lower

evel of PLD and LOX pro-oxidant enzymes activities accompaniedy boosted activities of enzymes from the antioxidant system (SOD,AT, GPX, GST, APX, DHAR and MDHAR) result in reduction of cellembrane damage because of membrane lipid peroxidation, and,

ltimately, to the avoidance of ROS accumulation, all of which has positive effect on CI tolerance, which is reflected in an improvedembrane integrity.

. Mechanism employed by salicylates and jasmonates forlleviating of chilling injury in fruits, vegetables and cutowers

Low temperature storage (LTS) has been the main strategypplied in postharvest to prolong shelf life of fruits and vegetablesnd maintain their quality. Storage at low temperature reduces theespiratory rate and minimizes fungal disease growth. However,ropical and subtropical fruits and vegetables are susceptible toow temperature treatment, and they suffer from chilling injury.hilling injury leads to undesirable effects on quality of fruits andegetables, such as abnormal ripening, pitting or browning. In caseshere its impact is very severe, it brings significant deterioration

f the produce and therefore has a great negative effect on its finalarket value and led to great economical losses. CI alleviating in

ruits and vegetables treated with salicylates and jasmonates coulde attributed to (1) Enhancing membrane integrity by reducingLD, PLC and LOX enzymes activities, enhancing unSFA/SFA ratiorobably through increase of FAD gene expression and maintainingnergy status, ATP and AEC. (2) Enhancing HSPs gene expres-ion and accumulation. (3) Enhancing antioxidant system activity.4) Enhancing arginine pathway which led to accumulation ofignaling molecules with pivotal roles in chilling tolerance suchs polyamines, nitric oxide, proline and GABA. (5) Activation of CBFathway and (6) alteration in PAL and PPO enzymes activities.

.1. Enhancing membrane integrity

Membrane fluidity has ability to regulate membrane functionhrough its effects on integral membrane proteins arrangement,

embrane permeability and transmembrane transport activityLos and Murata, 2004). Increase of membrane unsaturation degreeue to increase of unsaturated fatty acids such as linolenic acid18:3) led to enhance membrane fluidity, and cellular function cane enhanced by increasing membrane integrity. Increase of mem-rane fluidity decreases membrane tendency to phase change fromexible liquid crystalline to solid gels and results to enhance CI tol-rance (Los and Murata, 2004). Cao et al. (2009) observed that aeJA treatment of 10 �M for 24 h at 20 ◦C effectively alleviated CI in

oquat fruit. Alleviating of CI was associated with internal browningIB) decrease and maintenance of fruit firmness. In loquat fruit dur-ng storage at chilling temperature the levels of SFA such as palmiticnd stearic acid increased and those of unSFA such as linolenic andinoleic acids decreased so CI development was associated with aeduction of unSFA/SFA ratio. Linolenic and linoleic acid are theain substrates for LOX and their reduction could be attributed to

n increase of the enzymatic activity. MeJA treatment alleviated CIn loquat fruit also by reducing LOX activity and maintaining highnSFA/SFA ratios (Cao et al., 2009). Aghdam et al. (2012a) observedhat PLD and LOX activities in tomato fruit increased during

orticulturae 156 (2013) 73–85

development of CI symptoms, a fact indicating aggravation ofmembrane integrity loss. SA treatment significantly reduced theseenzymatic activities during storage at chilling temperature and ledto maintenance of membrane integrity (Aghdam et al., 2012a). Theauthors suggested that SA treatment induce CI tolerance in tomatofruit by rising membrane integrity upholding by means of reduc-ing the pro-oxidant PLD and LOX enzymatic activities, peroxidationlipids and loss of cell membrane semi-permeability. Jin et al. (2013)reported that MeJA treatment alleviated CI in peach fruit whichaccompanied with reducing electrolyte leakage, MDA, O2

•− andH2O2 contents. They reported that MeJA treatment increased thecontents of ATP and ADP, but decreased the content of AMP, whichresulted in a higher level of AEC in peach fruit. MeJA treatmentenhanced H+-ATPase, Ca2+-ATPase, succinic dehydrogenase (SDH)and cytochrome C oxidase (CCO) enzymes activities which are keyplayer in cell energy, ATP, production.

4.2. Enhancing antioxidant system activity

Yang et al. (2012) reported that a postharvest treatment ofpeach fruits with 1.0 mM SA for 10 min, alone or in combinationwith ultrasound treatment (40 kHz, 10 min), induced endogenousSA biosynthesis and at the same time was effective in alleviatingCI impact, but the SA treatment in combination with ultrasoundswas more effective than SA treatment alone. Since endogenousSA content in peach fruit treated with SA in combination withultrasound was higher than SA treatment alone, Yang et al. (2012)suggested that ultrasound treatment could assist in the penetrationof SA into the fruits, an event that may caused higher endogenousSA accumulation. The authors reported that antioxidant enzymesactivities (SOD, GST, CAT, APX, MDHAR, DHAR, GR) were enhancedin peach fruits treated with SA in combination with the ultrasoundtreatment, and they suggested that when SA and ultrasound wereused in combination, both treatments acted synergistically andthey were more effective in alleviating CI. Postharvest treatmentof sweet pepper with SA and CaCl2 contribute to maintain highlevels of AA via reduction of AA oxidase (AAO) activity, the enzymeresponsible for AA oxidation and thus for the loss of this key antiox-idant molecule (Rao et al., 2011). Reduction of AAO enzyme activityby this postharvest treatment was useful for the upholding of nutri-tional and organoleptic quality due to maintenance of AA content,which crucially contributes to the antioxidant capacity and it is alsocritical for its anti-browning property (Rao et al., 2011). Cao et al.(2010) reported that hot air (38 ◦C for 12 h) treatment and SA appli-cation (1 mM for 5 min), individually or in combination, alleviatedCI in peach fruit. In peach fruit treated with a combination of bothtreatments antioxidant enzymes activities (SOD, CAT, APX and GR)increased and LOX activity decreased. LOX is responsible of super-oxide radical production that after intervention of SOD enzymecould be converted into H2O2. H2O2 can be scavenged as resultof CAT, APX and GR enzymes activities (Mittler, 2002). Peachestreated with hot air in combination with SA increase SOD enzymeactivity and decrease LOX activity, meaning a rise of SOD/LOX ratiooccurred, which led to net reduction of superoxide radical leveland increase of CAT, APX and GR enzymes activities led to reduc-tion of H2O2 levels (Cao et al., 2010). Promyou et al. (2012) notedthat postharvest treatment with SA (2 mM for 15 min) alleviatedCI in anthurium flower, an effect associated with decreasing elec-trolyte leakage, MDA content and LOX activity, and increasing CATand SOD activities, which led to a diminution of spathe browningand fresh weight loss, two detrimental effects of CI on this orna-mental. Huang et al. (2008) reported that postharvest SA treatment
(2 mM for 30 min) increased H2O2 accumulation and SOD activityand decreased MDA content and CAT activity of ‘Cara cara’ navelorange fruit at 6 ◦C and 20 ◦C. This postharvest treatment stimu-lated GR and DHAR activities and GSH and AA contents that led

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M.S. Aghdam, S. Bodbodak / Scie

o enhanced AA/DHA and GSH/GSSG ratios. Enhancing H2O2 lev-ls in navel orange fruit treated with SA could be attributed to: (1)A-induction of SOD activity that facilitated conversion of O2

•− to2O2; (2) applied SA penetrated fruit and then it was combinedith iron ions and in that way it enhanced Haber-Weiss system

ctivity subsequently reducing H2O2 degradation (Huang et al.,008). Wang and Li (2006) observed that young grape plants underold and heat stresses treated with 100 �M SA had got a lower elec-rolyte leakage and MDA content in leaves. In grape leaves treatedith SA, APX and GR activities significantly increased, the rise of

he last enzymatic activity being responsible for maintenance ofSH pool, which allowed for GSH to be used by DHAR for reduc-

ion of DHA to AA. The authors suggested that high APX and GRctivities and AA/DHAA and GSH/GSSG ratios in SA-treated grapesehave as mechanisms of resistance towards heat and cold stresses.his SA treatment increased cytosolic Ca2+ concentrations in grapeeaves, an effect that may help to maintain membrane integritynder stressful conditions, a final beneficial result experimentallyonfirmed by the determination of diminished MDA content andlectrolyte leakage (Wang and Li, 2006). The authors suggested thatA treatment caused the translocation of Ca2+ from the vacuolend intercellular spaces to cytosol causing the rise of cytosolic Ca2+

oncentrations. Increase of cytosolic Ca2+ may enhance GR activ-ty that in its turn could increase GR/APX system activity and ledo increase of AA/DHAA and GSH/GSSG ratios. Also Huang et al.2008) considered that increase of AA/DHAA and GSH/GSSG ratiosn ‘Cara cara’ navel orange fruit treated with SA were due to a risef cytosolic Ca2+ concentration, which led to enhance of GR/APXystem activity. But this effect if excessive could conduct to dele-erious outcomes in the plant organ. An increase of cytosolic Ca2+

oncentration may lead to irreversible cell damage so SA-treatedrape leaves under cold and heat stresses had the ability to regu-ate transport of Ca2+ into the vacuole and intercellular spaces by

eans of stimulating PM-Ca2+-ATPase and V-Ca2+-ATPase activi-ies (Wang and Li, 2006). Calcium has got a fundamental role inell membrane integrity and cell wall strength. Calcium binding toell membrane components, particularly phospholipids, is essen-ial for the preservation of membrane integrity and the control ofts functionality (Aghdam et al., 2012c). Thus, SA could induce tol-rance to heat and cold stresses in grape plants via enhancementf the antioxidant system activity and maintenance of calciumomeostasis (Wang and Li, 2006). Ding et al. (2002) reported thateSA and MeJA treatments (0.01 mM for 16 h at 23 ◦C) signifi-

antly alleviated CI, manifested as surface pitting, and decay inomato fruit and this beneficial effect took place by induction ofathogenesis-related proteins (PRs) gene expression, such as chiti-ase and �-1,3-glucanase. Ding et al. (2002) found that CAT genexpression in MeJA-treated tomato fruits increased but in MeSA-reated decreased. The authors observed that MeSA increased H2O2ccumulation through reduction of CAT gene expression. H2O2 as aignal molecule has the ability to activate PRs genes expression. Inruits treated with MeSA, CAT gene expression was reduced in thearly period of cold storage, leading to H2O2 accumulation up to aevel which was sufficiently high to activate PRs gene expression,ut CAT gene expression rose in longer periods of cold storage inrder to prevent excessive H2O2 accumulation. Higher concentra-ions of MeSA had a negative impact on CI resistance in tomato fruithat could be attributed to the excessive accumulation of H2O2 asonsequence of the extreme reduction of CAT activity (Ding et al.,002). Wang et al. (2006) reported that postharvest SA treatment1 mM for 5 min) significantly alleviated CI and decay in peachruit. This CI alleviating was associated with MDA content decrease
nd maintenance of fruit firmness. Wang et al. (2006) found thatA/DHA and GSH/GSSG ratios and GSH content increased in peach
ruits treated with SA. Treatment of peach fruit with SA enhancedPX and GR enzymes activities. In SA-treated peach fruit, highest

orticulturae 156 (2013) 73–85 77

APX and GR enzymes activities coincide with highest AA/DHA andGSH/GSSG ratios and GSH content (Wang et al., 2006). Fung et al.(2004) reported that sweet peppers treated with 10−4 mM MeSAand MeJA conferred CI tolerance by means of increasing AOX geneexpression. AOX as an enzymatic mechanism to avoid ROS produc-tion has got a potential role in preventing ROS overproduction andthus inhibiting oxidative stress (Moller, 2001). Fung et al. (2004)observe that MeSA and MeJA treated sweet pepper fruits storedat 0 ◦C had got higher AOX gene expression and lower CI degreethan untreated fruits stored at the same temperature. The authorssuggested that these postharvest treatments and the so low tem-perature storage acted synergistically and caused further increasein AOX gene expression, which may be the ultimate responsiblefor increased resistance towards CI since AOX expression induc-tion is faster and broader in comparison with gene expression ofROS scavengers such as SOD, CAT and APX. The importance of AOXgene expression in conferring CI resistance to horticultural prod-ucts when stored at low temperatures has been confirmed by otherassays of MeSA and MeJA postharvest treatments. MeSA treatmenthad the ability to alleviate CI via increasing AOX gene expressionin tomato fruit harvested at pink maturation stage (Fung et al.,2006).

It has already been mentioned that a MeJA treatment of 10 �Mfor 24 h at 20 ◦C effectively alleviated CI in loquat fruit, an observa-tion verified by Cai et al. (2011). During IB development in loquatfruit reduction of AA content and increase of DHA content wasaccompanied with reduction of DHAR and MDHAR activities (Caiet al., 2011). The authors determined that the MeJA treatmentinduced DHAR and MDHAR activities and inhibited AAO activity,being the global effect a rise of the AA/DHA ratio. During IB devel-opment in loquat fruit, GSH content also decreased due to its use forthe biosynthesis of AA by DHAR but because of the rise in GR activ-ity, fruits treated with MeJA had net higher ratios of GSH/GSSG (Caiet al., 2011). GR activity was reduced during IB development butthis activity increased in fruits treated with MeJA, and this effectled to an increase of GSH levels. GSH produced by DHAR was con-sumed for conversion of DHA to AA (Mittler, 2002; Mittler et al.,2004). In summary, fruits treated with MeJA had high AA/DHA andGSH/GSSG ratios, being these two effects beneficial for the toler-ance against the oxidative stress associated with CI (Cai et al., 2011).Regarding MeJA action in inducing tolerance to CI in fruits, Caoet al. (2009) observed that a MeJA treatment of 10 �M for 24 hat 20 ◦C effectively alleviated CI in loquat fruit. Alleviating of CIwas associated with IB decrease and maintenance of fruit firm-ness. In loquat fruit during CI development CAT and APX activitiesdecreased and H2O2 and O2

•− levels increased but in MeJA-treatedfruits an increase of SOD activity occurred, which led to a decreaseof O2

•− content. This treatment also induced CAT and APX activ-ities, which in their turn led to diminution of the H2O2 producedby SOD action when catalyzing the degradation of O2

•− (Cao et al.,2009). LOX activity in loquat fruit increased during CI developmentand this effect increased the lipid peroxidation of membrane unsat-urated fatty acids but the MeJA treatment significantly reducedthis enzymatic activity being very beneficial for the maintenance ofmembrane integrity (Cao et al., 2009). Meng et al. (2012) observedthat treatment of Agaricus bisporus fungus with MeJA (100 �M for12 h at 20 ◦C) induced reduction of ROS levels associated with risesof SOD and CAT activities. The reduction of ROS levels leads toimprovement of cell membrane integrity and reduced cap brown-ing.

4.3. Enhancing HSPs accumulation

HSPs constitute a stress-responsive family of proteins whosemolecular weights range between 15 and 115 kDa. Five families ofHSPs have been identified: HSP70s, chaperonins (HSP60s), HSP90s,

7 ntia H

HHadWgc(2nietapppie

ibt(bpmv2sget

e(acfleit(cDaaaeraslmigrfdaite

gt


SP100s and HSPs with low molecular weight so called smallSPs (sHSPs). HSPs are found widely spread within the cytoplasmnd nucleus but also in cell compartments such as mitochon-ria, chloroplast and endoplasmic reticulum (Timperio et al., 2008;ang et al., 2004). Small HSPs (sHSPs), low molecular weight ran-

ing between 15 and 42 kDa, have chaperone activity which, inontrast to HSPs of higher molecular weight, is independent of ATPGusev et al., 2002). Ding et al. (2001) reported that heat (38 ◦C for

days), MeSA and MeJA (0.01 mM for 16 h at 23 ◦C) treatments sig-ificantly alleviated CI and decay of tomato fruit. These treatments

ncreased sHSPs gene expression during low temperature storage,specially that of HSP17.6. There is much evidence that HSPs exertheir protective role against stress by means of their chaperonectivity, which consists of (i) recognizing and binding to unfoldedroteins in order to correctly complete their folding, (ii) preventingrotein aggregation, and (iii) facilitating renaturation of aggregatedroteins. This chaperone activity of HSPs has been observed both

n vivo and in vitro (Ellis and Van der Vies, 1991; Lee, 1995; Bostont al., 1996; Sun et al., 2010).

sHSPs are able to exert their protective role against abiotic stressn especial ways that have not been observed in the rest of mem-ers of this protein family. First, they contribute to abiotic stressolerance due to their role as stabilizing agents of cell membranesNakamoto and Vigh, 2007; Horváth et al., 2008). Therefore mem-rane attributes such as fluidity and semi-permeability are at leastartially under the control of sHSPs and thus sHSPs may assist inaintaining fluidity and integrity of cell membranes in fruits and

egetables subjected to postharvest chilling stress (Torok et al.,001; Tsvetkova et al., 2002; Horváth et al., 2008). Zou et al. (2012)howed that electrolyte leakage is significantly reduced in trans-enic rice plants overexpressing OsHSP23.7 and OsHSP17.0 genesncoding for sHSPs and these transgenic lines displayed a higherolerance to drought and salt stress.

At the molecular level, the expression of heat-shock genesncoding HSPs is regulated by heat-shock transcription factorsHSTFs) that have the ability to sense heat and/or cold stressnd then activate HSPs gene expression by binding to heat-shockonsensus elements (HSEs), located in the TATA-box-proximal 5′-anking regions within the promoter of heat-shock genes. Theukaryotic HSE consensus sequence has been defined as alternat-ng units of 5′-nGAAn-3′, and efficient HSTF binding requires at leasthree units of this consensus, resulting in 5′-nGAAnnTTCnnGAAn-3′

Schoffl et al., 1998; Larkindale et al., 2005). HSTFs are present at theytoplasm of unstressed cells as a latent monomer that lacks bothNA binding and transcriptional activity. On stress exposure, HSTFsre converted from a monomeric to a trimeric form capable of high-ffinity HSE-binding capacity and transcriptional activation (Sorgernd Nelson, 1989; Al-Whaibi, 2011). But these HSTFs are also able toxert a protective role against the secondary oxidative stress occur-ing in most of the stressful conditions a plant may endure. Plantsre protected against this oxidative stress by a complex antioxidantystem including antioxidants enzymes and antioxidants metabo-ites. HSPs cooperate with this system at both levels. HSTFs, like

olecular sensors, are able to sense ROS such as H2O2 and accord-ngly regulate expression of oxidative stress response genes. Theene encoding for a pea ascorbate peroxidase (APX1), an enzymeesponsible for scavenging H2O2, contains in its promoter region aunctional HSTF binding motif (Mittler and Zilinskas, 1992). HSTF-ependent APX1 gene expression in Arabidopsis suggests that HSTFsre not only involved in regulating HSPs gene expression but alson the expression of genes involved in the antioxidant system func-ioning in order to enhance resistance to oxidative stress (Panchuk
t al., 2002).
In addition to this action of HSTFs regulating the expression ofenes encoding for antioxidant enzymes, HSPs are able to inducehe activity of antioxidant enzymes. Zhang et al. (2005) reported


that hot air treatment (38 ◦C for 10 h) alleviated CI in grape berry,with this rise of CI resistance being accompanied by a reduction ofelectrolyte leakage, MDA content and, finally, an increase in SODand CAT activities. The authors observed that the hot air treatmentled to an increase of HSP70 gene expression and that the accumula-tion of the HSP70 in grape directed an increase of gene expressionand activity of antioxidant enzymes and, finally, the synergisticaction between HSP70 and antioxidant system, resulting in mainte-nance of membrane integrity and induction of CI resistance (Zhanget al., 2005).

As well as increasing activity of antioxidant enzymes, HSPs areable to improve cell defense against oxidative stress by inducingthe accumulation of powerful antioxidant molecules such as GSH.Wang et al. (2006) reported that postharvest SA treatment signifi-cantly alleviated peach fruit CI, apparently by induction of HSP101and HSP73 protein expression, which in turn seems to influencethe rise of AA/DHA and GSH/GSSG ratios. Indeed, the authors sug-gest that the stimulation of HSP101 and HSP73 biosynthesis iscorrelated with GSH levels in SA-treated peaches, and the surgein CI tolerance in this fruits may be due to the synergic action ofboth HSPs and antioxidant system. By positively influencing theGSH/GSSG balance, HSP action allows the maintenance of GSH sup-ply to DHAR, which is responsible for conversion of DHA to AA (Sala,1998). Thus, in fruits and vegetables, HSPs may play a pivotal rolein regulating antioxidant system such as enhancing GSH level andincreasing antioxidant enzymes gene expression and/or activity,with both effects leading to a rise of resistance against postharvestCI in its oxidative stress facet.

In addition to their direct role in protecting cell membraneintegrity and fluidity in abiotic stress situations, sHSPs could alsoplay an indirect role increasing the plant response against sec-ondary osmotic and oxidative stresses caused by the primaryabiotic one, by means of increasing the endogenous proline con-tent. Regarding transgenic rice plants overexpressing OsHSP23.7and OsHSP17.0, Zou et al. (2012) reported that endogenous pro-line content was significantly high in these. Xue et al. (2009)observed in transgenic Arabidopsis overexpression yeast HSP26 thatthe endogenous proline content increased due to activation of pro-line biosynthesis genes such as pyrroline-5-carboxylate synthetase1 and 2 (AtP5CS1 and AtP5CS2), pyrroline-5-carboxylate reductase(AtP5CR), proline dehydrogenase 1 and 2 (AtPDH1 and AtPDH2)and ornithine aminotransferase (AtOAT), which led to increasedresistance to freezing injury.

In addition to these actions there are evidences that HSPs alsoplay a synergic action with antioxidant systems in order to pro-tect the plant from the secondary oxidative effect caused by stress.It is well-known that environmental stresses lead to a reductionof cell membrane integrity due to increasing ROS levels occur-ring in this situation, which provokes membrane lipid peroxidation(Fig. 1). In this facet of protective action of sHSPs against stress, Zouet al. (2012) observed that MDA levels were significantly lower inthe transgenic rice plants overexpressing OsHSP23.7 and OsHSP17.0subjected to salinity and drought stresses than in non-transformedplants. Regarding this last aspect, it has been suggested that sHSPsmay even be involved in ROS scavenging (Harndahl et al., 1999;Fedoroff, 2006). Hamilton and Heckathorn (2001) showed that inmaize plants subjected to salt stress, complex I of mitochondrialelectron transport chain is protected by antioxidant systems andsHSPs, but complex II is protected by osmoprotectants such as pro-line and betaine. These results indicate that NaCl stress damageto complex I is caused through oxidative stress and that HSPs mayprotect this complex by inducing some form of antioxidant activity.
Taking into account these results, it can be envisaged that sHSPs notonly had a role in prevention of protein misfolding under oxidativestress but they also had capability of inducing antioxidant activ-ity. Zou et al. (2012), Lee et al. (2012) and Harndahl et al. (1999)

M.S. Aghdam, S. Bodbodak / Scientia Horticulturae 156 (2013) 73–85 79

they

sestsstgaH

4

capo(ca(totti2

itTeTsanp

Fig. 3. Heat shock proteins: ways and molecular functions by which

uggested that the sHSPs have ROS scavenging activity and the ben-ficial effects of this activity is enhancing resistance against chillingtress. Neta-Sharir et al. (2005) reported that HSP21 protectsomato photosystem II from temperature-dependent oxidativetress. Taken together, CI mitigation by increasing HSPs expres-ion and accumulation via postharvest salicylates and jasmonatesreatments could be attributed to: (1) chaperone activity that is aeneral characteristic of this protein family, (2) the action of sHSPss stabilizers of cell membranes, and (3) the synergistic action ofSPs with antioxidant systems (Fig. 3).

.4. Enhancing arginine pathways

Arginine as metabolically multifunctional amino acids playsrucial roles not only as a building block of proteins, but also as

precursor for the biosynthesis of signaling molecules such asolyamines (putrescine, spermidine, spermine), proline and nitricxide (NO) which play potential role in enhancing tolerance to CIFig. 4; Gao et al., 2009; Morris, 2009; Jubault et al., 2008). Argininean be catabolized through the action of three crucial enzymes:rginase, arginine decarboxylase (ADC) and nitric oxide synthaseNOS) (Morris, 2009). Arginase catalyzes the conversion of arginineo ornithine, which in turn can serve as precursor for biosynthesisf proline and polyamines. It has been suggested that the produc-ion of polyamines or proline can serve as a tolerance mechanismo chilling stress as economically important postharvest problemn sensitive fruits and vegetables (Zhang et al., 2011; Shang et al.,011).

Arginine could be converted to ornithine by arginase. Ornithines one of the two main precursors of polyamines and convertedo putrescine by ornithine decarboxylase (ODC) enzyme activity.he second pathway for polyamine biosynthesis is possible via ADCnzyme which is responsible for converting arginine to putrescine.he anti-senescence biogenic polyamines (PAs) putrescine (Put),
permidine (Spd) and spermine (Spm) are able to bind to neg-tively charged molecules such as phospholipids, proteins anducleic acids owing to their polycationic nature at physiologicalH. Because of the interaction of PAs with the anionic groups of
are capable of enhancing chilling tolerance in fruits and vegetables.

membrane phospholipids the binding of these molecules to thisgroup of lipids could stabilize cell membranes under CI stressand therefore delay their disintegration (Groppa and Benavides,2008). Also, PAs exhibits antioxidant activity and scavenging of ROSand enhancing membrane stability and integrity under CI stress(Hussain et al., 2011).

Also, ornithine biosynthesized from arginine by arginaseenzyme activity could convert to proline by ornithine aminotrans-ferase (OAT) enzyme activity which has important role in fruit andvegetable resistance to CI (Hussain et al., 2011). Proline biosyn-thesis can also be done via P5CS enzymes activities which areresponsible for the conversion of glutamate to proline. During coldstorage of fruits and vegetables, the increased proline content ledto increased resistance to CI. Proline have a multifaceted natureand plays key roles in the osmotic regulation between cytoplasmand vacuole, the redox regulation of the NAD+/NADH ratio, mem-brane stabilizer and finally in promoting ROS scavenging systems(Sharp et al., 1990; Bohnert and Jensen, 1996). Arginine can alsobe converted to NO as hydrophobic diffusible gaseous moleculevia NOS enzyme activity (Zhang et al., 2011). PAs, NO and prolineas signaling molecules play crucial roles in enhancing resistanceto CI in fruits and vegetables. Zhang et al. (2011) observed that apostharvest treatment of 0.05 mM MeSA for 12 h at 20 ◦C alleviatedCI in tomato fruit when stored at 2 ◦C for up to 28 days after MeSAapplication. Fruits treated with MeSA exhibited an increased geneexpression and enzymatic activity for arginase, ODC and ADC, all ofthem enzymes involved in polyamines biosynthesis. This obser-vation explains that the authors determined higher polyaminescontent (Put, Spd and Spm) in MeSA-treated fruits. Augmentedendogenous polyamine contents along with increasing endogenousNO, due to higher activity of the enzyme responsible for its biosyn-thesis, NOS, led to increased CI resistance in tomato fruits due tothis postharvest treatment with MeSA (Zhang et al., 2011). Zhanget al. (2012) reported that postharvest treatment with 0.05 mM
MeJA for 12 h at 20 ◦C reduced CI symptoms in cherry tomato fruitwhen it was subsequently stored at 2 ◦C during 21 days. MeJA treat-ment induced gene expression and activity of arginase, ODC andADC enzymes in a similar way as it did MeSA treatment (Zhang


to bi

epiaiTC

saambaMeCcaia(otricadwi

Fig. 4. Schematic diagram of arginine pathways which led

t al., 2011), having the same final consequences of stimulatingolyamine biosynthesis (especially Put). But also MeJA treatment

ncreased proline content by means of inducing gene expressionnd enzymatic activity of arginase and OAT, both enzymes involvedn the production of proline from the arginine/ornithine pathway.he rise of polyamine and proline contents played a pivotal role inI alleviating in MeJA-treated tomato fruit (Zhang et al., 2012).

Luo et al. (2011) observed that SA treatment (1.5 mM for 10 min)ignificantly reduced CI effect in plum fruits and this event wasssociated with enhanced endogenous polyamines accumulationnd led to reduction of MDA, associated with improved cellembrane integrity (Luo et al., 2011). Postharvest treatment of

amboo shoot with 1.0 mM SA for 15 min effectively alleviated CI,nd this effect was associated with reducing electrolyte leakage,DA and total phenol contents, and shoot tissue browning (Luo

t al., 2012). The authors suggested that SA treatment alleviatedI in bamboo shoot via enhancement of endogenous polyaminesontents (Put, Spd and Spm). Cao et al. (2010) reported that hotir (38 ◦C for 12 h) treatment and SA application (1 mM for 5 min),ndividually or in combination, alleviated CI in peach fruit. Theuthors observed that increase of endogenous polyamines contentPut, Spd and Spm) in peach fruits treated with this combinationf postharvest treatments were significantly higher than whenreated with hot air or SA individually, a result that yield a higher CIesistance. Kausch et al. (2012) reported that silencing of LOX genen tomato, an enzyme participating in JA biosynthesis, led to defi-ient endogenous MeJA levels during fruit development. The lesser
ccumulation of MeJA in the transgenic tomato fruits led to markediminutions of polyamines (Put, Spd and Spm) and GABA contents,hich suggested that the endogenous MeJA played pivotal roles
n accumulation of polyamines and GABA signaling molecules.

osynthesis of polyamines, nitric oxide, proline and GABA.

GABA is a four carbon, non-protein amino acid which playsa crucial role as a signaling molecule in response to postharveststress such as CI (Shelp et al., 1999; Kinnersley and Turano,2000). In addition to anti-chilling function of GABA in fruits andvegetables, GABA plays an important role in human health due toits antihypertensive effects (Mae et al., 2012). So, in addition toalleviating of CI, increase of endogenous levels of GABA in fruitsand vegetables by postharvest treatments such as high CO2 intomato (Deewatthanawong et al., 2010a) and strawberry fruit(Deewatthanawong et al., 2010b), MeJA in loquat fruit (Cao et al.,2012) or GABA in peach fruit (Shang et al., 2011; Yang et al., 2011)could have beneficial effects on human health. GABA metabolismoccurs in GABA shunt which consist of 3 enzymes activities: (1)glutamate decarboxylase (GAD), as a key enzyme is responsible forconversion of glutamate to GABA. (2) GABA transaminase (GABA-T)which is responsible for conversion of GABA to succinic semialde-hyde (SSA); (3) succinic semialdehyde dehydrogenase (SSADH)which is responsible for conversion of SSA to succinate (Kinnersleyand Turano, 2000). GAD activity independently regulates by pH andcalcium/calmodulin (Ca-CaM). When pH is reduced, GAD activityincreases but at neutral pH, GAD is activated via binding to Ca-CaM(Gut et al., 2009). As, decarboxylation of glutamate to GABA byGAD is associated with consumption of H+, increase of GAD activityin fruit and vegetable treated with postharvest treatment such ashigh CO2 leads to cytoplasm pH adjustment and prevents acidifi-cation of cytosol under chilling stress (Merodio et al., 1998). Caoet al. (2012) reported that MeJA treatment (10 �M for 24 h at 20 ◦C)
effectively alleviated CI in loquat fruit. In loquat fruit subjected to aMeJA treatment of 10 �M for 24 h at 20 ◦C and subsequently storedat 1 ◦C for 35 days OAT and P5CS activities, enzymes responsiblefor proline biosynthesis, increased and PDH activity, enzyme

ntia H

rrGcblrtsGhflGCaawhloip2

4

(Da(feewclsstMbtt2eplaCbt2sr(tbtffoao2


esponsible for proline degradation, decreased, being the finalesult of this enzymatic balance a rise in proline content. Similarly,ABA content in MeJA-treated loquat fruit increased during theold storage. GABA was biosynthesized through glutamate decar-oxylation by the GAD enzyme. Increase of GABA content in treated

oquat fruit during low temperature storage was associated witheduction of GAD activity (Cao et al., 2012). The authors suggestedhat increase of GABA content in response to low temperaturetorage was probably due to reduction of GABA degradation byABA-T as it has been observed in tomato fruit subjected to aigh CO2 treatment (Deewatthanawong et al., 2010b). The results

rom Cao et al. (2012) showed that loquat fruit was able to senseow temperature stress and as response it increased proline andABA levels but such increases were not enough for overcomingI. In loquat fruit treated with MeJA, increase of OAT and P5CSctivities that led to higher ratios of proline biosynthesis andccumulation was associated with a reduction of PDH activity,hich prevented proline degradation and led to a significantlyigher increase of proline content. Also, the MeJA treatment

ed to an extra increase of GABA content through a higher risef GAD activity, so in summary the induction of CI tolerancen loquat fruit by MeJA treatment was mainly due to enhancedroline and GABA production and accumulation (Cao et al.,012).

.5. Activation of CBF pathway

CBF as a transcription factor activate cold responsive genesCOR) genes expression via recognize and bind to the C-repeat/DRENA regulatory elements and thus play powerful role in fruitsnd vegetables tolerance to CI (Zhao et al., 2009). Zhao et al.2012) reported that MeJA treatment of banana fruit at 0.1 mMor 30 min under 0.1 MPa of pressure significantly induce CI tol-rance, an observation which was accompanied with reduction oflectrolyte leakage and increase of proline content. Fruits treatedith MeJA had got high values of the colorimetric parameters hue,

hroma and lightness, revealing low CI impact. MeJA treatmented to endogenous JA accumulation via induction of the expres-ion of the octadecanoic pathway genes such as LOX1, allene oxideynthase 2 (AOS2) and allene oxide cyclase 1 (AOC1). The MeJAreatment led to an induction of the expression of MaMYC2a andaMYC2b genes during posterior cold storage (7 ◦C) of banana fruit,

oth genes coding for isoforms of a basic helix-loop-helix (bHLH)ranscription factor, MYC2. MYC2 is a key regulator in the activa-ion of the JA response (Cheng et al., 2011; Fernández-Calvo et al.,011; Niu et al., 2011). But the authors observed that MaICE1 genexpression, which product is the inducer of the CBF regulon in thelant response against cold stress (Chinnusamy et al., 2003), was

argely independent from MeJA treatment (Zhao et al., 2012). ICEs basic helix-loop-helix (bHLH) transcription factor is upstreamBF regulator and could plays crucial role in fruits and vegeta-les tolerance to CI by activating CBF genes expression in responseo chilling stress via binding to theirs promoters (Fursova et al.,009). Like in Arabidopsis the banana homolog MaICE1 is con-titutively expressed and therefore it may be post-translationallyegulated to activate the expression of its downstream target genesChinnusamy et al., 2003). Zhao et al. (2012) provide evidencehat MaMYC2 is involved in MeJA-induced chilling tolerance inanana fruit by physically interacting with MaICE1. The result ishat the products from both genes are likely to be coordinatelyunctioning, leading to enhancement of CI tolerance of bananaruit via induction of the CBF regulon, stimulating the expression
f genes belonging to this regulon such as MaCBF1 and MaCBF2,nd of those downstream regulated in their turn by these lastnes, such as MaCOR1, MaKIN2, MaRD2 and MaRD5 (Zhao et al.,012).
orticulturae 156 (2013) 73–85 81

4.6. Alteration in PAL and PPO enzymes activities

It is well known that when fruits and vegetables are stored underchilling temperature: (1) PAL activity increases due to the CI effectinducing increase of total phenols (TP) that accumulates in vac-uoles; (2) a membrane selective permeability loss occurs; (3) PPOactivity increases in cytoplasm that is responsible for flesh or inter-nal browning; (4) phenolics compounds accumulated in vacuolesleak to cytoplasm due to loss of vacuole membrane (tonoplast)selective permeability and contribute to IB incidence, an effectinfluenced by PAL activity (Sevillano et al., 2009).

Luo et al. (2011) observed that SA treatment (1.5 mM for 10 min)significantly reduced CI effect in plum fruits and this event wasassociated with decreased electrolyte leakage and MDA content,and diminished POD and PPO activities, which are the main respon-sible for fruit flesh browning, a major CI detrimental effect on peachquality. But even SA can be applied during preharvest to exert itsbeneficial effect during postharvest. Lu et al. (2011) applied prehar-vest SA spray (PSS, 2 mM for 15 min) and postharvest SA immersion(PSI, 5 mM for 15 min) treatments in pineapple and observed thatboth treatments alleviated CI. Lu et al. (2011) reported that theobserved IB reduction in pineapple fruit treated with PSS and PSIcould be attributed to diminution of PPO and PAL activities. Also AAis known because for its anti-browning effect and the high levelsof this antioxidant molecule found in pineapple fruit treated withPSS and PSI could contribute to IB reduction, so maintenance of AAlevels is also another beneficial effect of PSS and PSI treatments (Luet al., 2011). Postharvest treatment of bamboo shoot with 1.0 mMSA for 15 min effectively alleviated CI, and this effect was associatedwith reducing electrolyte leakage, MDA and total phenol contents,and shoot tissue browning (Luo et al., 2012). The authors suggestedthat SA treatment alleviated CI in bamboo shoot via retardationof enzymatic activities responsible for browning (PPO and PAL).Postharvest treatment with ASA at 1 mM for 5 min at pH 3.5 alle-viated CI impact on loquat fruit and this outcome was associatedwith decreased internal and external browning, electrolyte leakageand lignification (Cai et al., 2006). PAL, cinnamyl alcohol dehy-drogenase (CAD) and guaiacol peroxidase (GOX) activities wereresponsible for loquat fruit tissue lignification, which were associ-ated with increasing fruit firmness and lignin content and reductionof fruit juice percentage, both deleterious effects on the fruit qual-ity. Postharvest treatment of loquat fruit with ASA reduced lignincontent and fruit firmness, and increased fruit percentage juice andthis reduction of lignification was accompanied with reduction ofPAL, CAD and GOX activities (Cai et al., 2006). Also this posthar-vest treatment with ASA reduced superoxide radical content andled to reduction of electrolyte leakage. Finally, endogenous freeSA content in ASA-treated loquat fruit was significantly increased,which was presumably attributed to rapid conversion of the exoge-nously applied ASA to SA by the fruit metabolism (Cai et al., 2006).The treatment of pomegranates with SA (2 mM for 10 min) alle-viated CI impact in fruit, confirmed by the observed reduction ofelectrolyte leakage and PAL activity (Sayyari et al., 2009). Consid-ering an increase of AA levels in SA-treated fruits was observed,the authors suggested that the antioxidant system and the cellmembrane fluidity are probably as or more important in confer-ring CI tolerance than PAL activity itself. Jin et al. (2009) reportedthat LTC (10 ◦C, 2d) in combination with MeJA treatment (1 �M for48 h at 20 ◦C) was more effective than treatments LTC and MeJAalone to attain reduction of CI impact in peach fruit, assessed by IBand flesh mealiness (FM). This combination of postharvest treat-ments, LTC and MeJA treatments resulted in an increase of PAL
activity and TP content, increase of antioxidant enzymes activitysuch as APX, CAT and SOD, reduction of H2O2 levels and reduc-tion of PPO and POX activities (Jin et al., 2009). Imbalance betweenpolygalacturonase (PG) and pectin methyl esterase (PME) activities


asmon

(ubio(dP

atdsfoftfiattapafewoowraP

Fig. 5. Schematic overview of mechanisms by which salicylates and j

PG/PME lower ratio) caused accumulation of insoluble high molec-lar weight pectin that has their methyl ester removed by PME,ut they were not depolymerized due to lower activity of PG. The

nsoluble pectins held free water in the gel and caused reductionf free juice and development of FM (Zhou et al., 2000). Jin et al.2009) suggested that the LTC in combination with MeJA treatmentecreased FM and increased extractable juice through increase ofG/PME ratio.

MeSA and MeJA treatments (0.1 and 0.01 mM for 16 h at 20 ◦C)lleviated CI in pomegranate fruit and this stress tolerance induc-ion was associated with maintenance of membrane integrity,etermined by decreasing electrolyte leakage, and a retarding fruitoftening (Sayyari et al., 2011a). Also, treatment of pomegranateruit with ASA (1 mM for 10 min) induced tolerance towards CI, anbservation associated with reduction of electrolyte leakage andruit skin browning (Sayyari et al., 2011b). The authors suggestedhat reduction of respiration rate in ASA-treated pomegranateruits along with maintenance of fruit firmness could be the caus-ng effects for this tolerance. A question arises from all thesessays described up to now, and it is if CI alleviating due to ASAreatment is caused by the exogenous applied ASA per se or onhe other hand by the SA resulting from the conversion of thispplied ASA by the cell metabolism. Lu et al. (2010) reported thatostharvest treatment with SA (5 mM for 15 min) alleviated IBs a CI symptom in pineapple fruit. IB alleviating in pineappleruit treated with SA associated with increasing of SOD and APXnzymes activities. Increase of SOD and APX enzymes activitiesas linked to ROS decrease and the final result was alleviating

f IB (Lu et al., 2010). It was observed that during cold storagef pineapple fruit high activities of POX, PPO and PAL coincided
ith high occurrence of IB. Since SA treatment of pineapple fruit
educed POX, PPO and PAL activities the authors suggested thatlleviating of IB was due to reduction of these enzymatic activities.ineapple fruit treated with SA had high levels of AA compared

ates enhances chilling tolerance in fruits, vegetables and cut flowers.

with non-treated fruits and, according to the well-known anti-browning properties of AA, IB reduction could attributed to thisincrease of AA content (Lu et al., 2010). Aghdam et al. (2012b)observed that postharvest treatment of tomato fruit with 1 mM SAfor 5 min markedly reduced CI symptoms. In this assay CI allevi-ating was associated with reduced electrolyte leakage and MDAcontent and elevated proline content. SA treatment had no signif-icant effect on total phenols content but it significantly decreasedPAL activity. PAL as a key enzyme in the phenylpropanoids path-way catalyzing the conversion of phenylalanine to trans-cinnamicacid. PAL connected primary metabolism (shikimic acid path-way) with secondary metabolism (phenylpropanoids pathway)(Dixon and Paiva, 1995). In general terms it has been acceptedby the scientific community that an increase of PAL activity infruit stored at chilling temperatures is part of the response ofthe plant organ in order to alleviate CI (Rinaldo et al., 2010).Postharvest heat treatment alleviated CI in banana fruit by meansof increasing PAL activity (Chen et al., 2008). Anyway, Aghdamet al. (2012b) determined a decreasing PAL activity in tomato fruitstreated with SA treatment. These results are in accordance withreports from Cai et al. (2006), Dangcham et al. (2008), Sayyariet al. (2009), and Lu et al. (2010, 2011). Supporting the findingsof Aghdam et al. (2012b) regarding PAL activity, Nguyen et al.(2004) observed that modified atmosphere packaging (MAP) treat-ment significantly alleviated CI in banana fruit and the alleviatingwas associated with a diminution of PAL activity. Sanchez-Ballestaet al. (2000) observed that PAL activity rose was correlated withCI symptoms development in mandarin fruit during cold stor-age. Heat treatment significantly alleviated CI and this effect wasassociated with decrease of PAL activity (Sanchez-Ballesta et al.,
2000). Meng et al. (2012) observed that treatment of Agaricus bis-porus fungus with MeJA (100 �M for 12 h at 20 ◦C) reduced capbrowning through decrease of PPO gene expression and enzymaticactivity.

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. Conclusion

Tropical and subtropical fruits and vegetables and also cutowers are sensitive to low temperatures and suffer from chilling

njury. The incidence of this physiological disorder limits the usef low temperatures storage, the strategy employed most widelyor marketing tropical and subtropical fruits and vegetables. Mem-rane damage and ROS production are multifarious adverse effectsf chilling as oxidative stress in sensitive fruits and vegetables.oday, postharvest technologies are employed in order to inhibit oreduce the impact of CI in sensitive fruits and vegetables with com-ercial interest. These technologies can be of a physical, chemical

r biotechnological nature. The reluctance of consumers regardinghe chemical treatment of fruits and vegetables has promotedhe use of environmentally friendly technologies before or duringhe cold storage. SA, as natural and safe phenolic molecule, aton-toxic concentrations may be commercially used in alleviatingI in fruits, vegetables and flowers. For alleviating of CI in fruits andegetables, it has been suggested that the SA and MeSA are inex-ensive, easy to set up and applicable treatments. Thus SA has highommercial potential for use at low concentrations in alleviatingI in fruits, vegetables and flowers. Also, treatment with MeJAt non-toxic concentrations alleviates CI in fruits and vegetables.rom these results presented herein we conclude that salicylatesnd jasmonates treatments enhanced chilling tolerance in fruitsnd vegetables which was attributed to the followings (1) Enhanc-ng membrane integrity by reducing PLD, PLC and LOX enzymesctivities, enhancing unSFA/SFA ratio probably through increasef FAD gene expression and maintaining energy status, ATP andEC. (2) Enhancing HSPs gene expression and accumulation. (3)nhancing antioxidant system activity. (4) Enhancing arginineathway which led to accumulation of signaling molecules withivotal roles in chilling tolerance such as polyamines, nitric oxide,roline and GABA and (5) activation of CBF pathway, (6) alteration

n PAL and PPO enzymes activities (Fig. 5).

cknowledgements

We are extremely grateful to Dr. Francisco B. Flores, CEBAS-CSIC,ampus de Espinardo, Espinardo-Murcia, Spain and Dr. Laura Sevil-

ano, IBFG-UAL/CSIC, Edificio Departamental, Campus Miguel denamuno, Salamanca, Spain, for their valuable comments on theanuscript and providing Figs. 1 and 2.

eferences

ghdam, M., Asghari, M., Khorsandi, O., Mohayeji, M., 2012a. Alleviation of posthar-vest chilling injury of tomato fruit by salicylic acid treatment. J. Food Sci.Technol., 1–16.

ghdam, M.S., Asghari, M., Moradbeygi, H., Mohammadkhani, N., Mohayeji, M.,Rezapour-Fard, J., 2012b. Effect of postharvest salicylic acid treatment on reduc-ing chilling injury in tomato fruit. Rom. Biotechnol. Lett. 17, 7466–7473.

ghdam, M.S., Hassanpouraghdam, M.B., Paliyath, G., Farmani, B., 2012c. The lan-guage of calcium in postharvest life of fruits vegetables and flowers. Sci. Hortic.144, 102–115.

l-Whaibi, M.H., 2011. Plant heat-shock proteins: a mini review. J. King Saud. Uni.Sci. 23, 139–150.

sghari, M., Aghdam, M.S., 2010. Impact of salicylic acid on post-harvest physiologyof horticultural crops. Trend Food Sci. Technol. 21, 502–509.

ohnert, H.J., Jensen, R.G., 1996. Strategies for engineering water-stress tolerancein plants. Trends Biotech. 14, 89–97.

oston, R.S., Viitanen, P.V., Vierling, E., 1996. Molecular chaperones and proteinfolding in plants. Plant Mol. Biol. 32, 191–222.

rown, D.J., Beevers, H., 1987. Fatty acids of rice coleoptiles in air and anoxia. PlantPhysiol. 84, 555–559.

ai, C., Li, X., Chen, K., 2006. Acetylsalicylic acid alleviates chilling injury of posthar-vest loquat (Eriobotrya japonica Lindl) fruit. Eur. Food Res. Technol. 223, 533–539.

ai, Y., Cao, S., Yang, Z., Zheng, Y., 2011. MeJA regulates enzymes involved in ascorbicacid and glutathione metabolism and improves chilling tolerance in loquat fruit.Postharvest Biol. Technol. 59, 324–326.

orticulturae 156 (2013) 73–85 83

Cao, S., Cai, Y., Yang, Z., Zheng, Y., 2012. MeJA induces chilling tolerance in loquatfruit by regulating proline and �-aminobutyric acid contents. Food Chem. 133,1466–1470.

Cao, S., Yang, Z., Cai, Y., Zheng, Y., 2011. Fatty acid composition and antioxidantsystem in relation to susceptibility of loquat fruit to chilling injury. Food Chem.127, 1777–1783.

Cao, S., Zheng, Y., Wang, K., Jin, P., Rui, H., 2009. Methyl jasmonate reduces chillinginjury and enhances antioxidant enzyme activity in postharvest loquat fruit.Food Chem. 115, 1458–1463.

Cao, S., Hu, Z., Zheng, Y., Lu, B., 2010. Synergistic effect of heat treatment and salicylicacid on alleviating internal browning in cold-stored peach fruit. Postharvest Biol.Technol. 58, 93–97.

Chen, J.Y., He, L.H., Jiang, Y.M., Wang, Y., Joyce, D.C., Ji, Z.L., Lu, W.J., 2008. Role ofphenylalanine ammonia-lyase in heat pretreatment-induced chilling tolerancein banana fruit. Physiol. Plant. 132, 318–328.

Cheng, Z., Sun, L., Qi, T., Zhang, B., Peng, W., Liu, Y., Xie, D., 2011. The bHLH transcrip-tion factor MYC3 interacts with the jasmonate ZIM domain proteins to mediatejasmonate response in Arabidopsis. Molecular Plant. 4, 279–288.

Chinnusamy, V., Ohta, M., Kanrar, S., Lee, B.H., Hong, X., Agarwa, M., Zhu, J.K., 2003.ICE1: a regulator of cold-induced transcriptome and freezing tolerance in Ara-bidopsis. Genes Dev. 17, 1043–1054.

Crawford, R.M.M., Braendle, R., 1996. Oxygen deprivation stress in a changing envi-ronment. J. Exp. Bot. 47, 145–159.

Dangcham, S., Bowen, J., Ferguson, I.B., Ketsa, S., 2008. Effect of temperature and lowoxygen on pericarp hardening of mangosteen fruit stored at low temperature.Postharvest Biol. Technol. 50, 37–44.

Deewatthanawong, R., Nock, J.F., Watkins, C.B., 2010a. �-Aminobutyric acid (GABA)accumulation in four strawberry cultivars in response to elevated CO2 storage.Postharvest Biol. Technol. 57, 92–96.

Deewatthanawong, R., Rowell, P., Watkins, C.B., 2010b. �-Aminobutyric acid (GABA)metabolism in CO2 treated tomatoes. Postharvest Biol. Technol. 57, 97–105.

Ding, C.-K., Wang, C.Y., Gross, K.C., Smith, D.L., 2001. Reduction of chilling injuryand transcript accumulation of heat shock proteins in tomato fruit by methyljasmonate and methyl salicylate. Plant Sci. 161, 1153–1159.

Ding, C.K., Wang, C.Y., Gross, K.C., Smith, D.L., 2002. Jasmonate and salicylate inducethe expression of pathogenesis-related-protein genes and increase resistance tochilling injury in tomato fruit. Planta 214, 895–901.

Dixon, R.A., Paiva, N.L., 1995. Stress-induced phenylpropanoid metabolism. PlantCell 7, 1085–1097.

Fedoroff, N., 2006. Redox regulatory mechanisms in cellular stress responses. Ann.Bot. 98, 289–300.

Ellis, R.J., Van der Vies, S.M., 1991. Molecular chaperones. Annu. Rev. Biochem. 60,321–347.

Fernández-Calvo, P., Chini, A., Fernández-Barbero, G., Chico, J.M., Gimenez-Ibanez, S.,Geerinck, J., Eeckhout, D., Schweizer, F., Godoy, M., Franco-Zorrilla, J.M., Pauwels,L., Witters, E., Puga, M.I., Paz-Ares, J., Goossens, A., Reymond, P., De Jaeger, G.,Solano, R., 2011. The Arabidopsis bHLH transcription factors MYC3 and MYC4are targets of JAZ repressors and act additively with MYC2 in the activation ofjasmonate responses. Plant Cell 23, 701–715.

Fung, R.W.M., Wang, C.Y., Smith, D.L., Gross, K.C., Tao, Y., Tian, M., 2006. Charac-terization of alternative oxidase (AOX) gene expression in response to methylsalicylate and methyl jasmonate pre-treatment and low temperature in toma-toes. J. Plant Physiol. 163, 1049–1060.

Fung, R.W.M., Wang, C.Y., Smith, D.L., Gross, K.C., Tian, M., 2004. MeSA and MeJAincrease steady-state transcript levels of alternative oxidase and resistanceagainst chilling injury in sweet peppers (Capsicum annuum L). Plant Sci. 166,711–719.

Fursova, O.V., Pogorelko, G.V., Tarasov, V.A., 2009. Identification of ICE2, a geneinvolved in cold acclimation which determines freezing tolerance in Arabidopsisthaliana. Gene 429, 98–103.

Gao, H.-J., Yang, H.-Q., Wang, J.-X., 2009. Arginine metabolism in roots and leavesof apple (Malus domestica Borkh.): the tissue-specific formation of both nitricoxide and polyamines. Sci. Hortic. 119, 147–152.

Groppa, M.D., Benavides, M.P., 2008. Polyamines and abiotic stress: recent advances.Amino Acids 34, 35–45.

Gusev, N.B., Bogatcheva, N.V., Marston, S.B., 2002. Structure and properties of smallheat shock proteins (sHsp) and their interaction with cytoskeleton proteins.Biochemistry 67, 511–516.

Gut, H., Dominici, P., Pilati, S., Astegno, A., Petoukhov, M.V., Svergun, D.I., Grutter,M.G., Capitani, G., 2009. A common structural basis for pH- and calmodulin-mediated regulation in plant glutamate decarboxylase. J. Mol. Biol. 392,334–351.

Hamilton 3rd, E.W., Heckathorn, S.A., 2001. Mitochondrial adaptations to NaCl,Complex I is protected by anti-oxidants and small heat shock proteins,whereas complex II is protected by proline and betaine. Plant Physiol. 126,1266–1274.

Harndahl, U., Hall, R.B., Osteryoung, K.W., Vierling, E., Bornman, J.F., Sundby, C., 1999.The chloroplast small heat shock protein undergoes oxidation-dependent con-formational changes and may protect plants from oxidative stress. Cell StressChap. 4, 129–138.

Hernández, M.L., Padilla, M.N., Sicardo, M.D., Mancha, M., Martínez-Rivas, J.M.,
2011. Effect of different environmental stresses on the expression of oleatedesaturase genes and fatty acid composition in olive fruit. Phytochemistry 72,178–187.
Hodges, D.M., DeLong, J.M., Forney, C.F., Prange, R.K., 1999. Improving the thiobar-bituric acid-reactive-substances assay for estimating lipid peroxidation in plant

http://refhub.elsevier.com/S0304-4238(13)00153-2/SBREF0005





























































































































































































































































































































































































































































































































































































































































































































































































8 ntia H

H

H

H

J

J

J

K

K

L

L

L

L

L

L

L

L

LM

M

M

M

M

M

M

M

M

M

M

M

N


tissues containing anthocyanin and other interfering compounds. Planta 207,604–611.

orváth, I., Multhoff, G., Sonnleitner, A., Vígh, L., 2008. Membrane-associatedstress proteins: more than simply chaperones. Biochim. Biophys. Acta 1778,1653–1664.

uang, R.H., Liu, J.H., Lu, Y.M., Xia, R.X., 2008. Effect of salicylic acid on the antioxi-dant system in the pulp of ‘Cara cara’ navel orange (Citrus sinensis L Osbeck) atdifferent storage temperatures. Postharvest Biol. Technol. 47, 168–175.

ussain, S.S., Ali, M., Ahmad, M., Siddique, K.H.M., 2011. Polyamines: natural andengineered abiotic and biotic stress tolerance in plants. Biotechnol. Adv. 29,300–311.

in, P., Wang, K., Shang, H., Tong, J., Zheng, Y., 2009. Low-temperature conditioningcombined with methyl jasmonate treatment reduces chilling injury of peachfruit. J. Sci. Food Agric. 89, 1690–1696.

in, P., Zhu, H., Wang, J., Chen, J., Wang, X., Zheng, Y., 2013. Effect of methyl jasmonateon energy metabolism in peach fruit during chilling stress. J. Sci. Food Agric. 26.

ubault, M., Hamon, C., Gravot, A., Lariagon, C., Delourme, R., Bouchereau, A.,Manzanares-Dauleux, M.J., 2008. Differential regulation of root argininecatabolism and polyamine metabolism in clubroot-susceptible and partiallyresistant Arabidopsis genotypes. Plant Physiol. 146, 2008–2019.

ausch, K.D., Sobolev, A.P., Goyal, R.K., Fatima, T., Laila-Beevi, R., Saftner, R.A.,Handa, A.K., Mattoo, A.K., 2012. Methyl jasmonate deficiency alters cellularmetabolome including the aminome of tomato (Solanum lycopersicum L.) fruit.Amino Acids 42, 843–856.

innersley, A.M., Turano, F.J., 2000. Gamma aminobutyric acid (GABA) and plantresponses to stress. Crit. Rev. Plant Sci. 19, 479–509.

arkindale, J., Hall, J.D., Knight, M.R., Vierling, E., 2005. Heat stress phenotypes ofArabidopsis mutants implicate multiple signaling pathways in the acquisitionof thermotolerance. Plant Physiol. 138, 882–897.

ee, G.J., 1995. Assaying proteins for molecular chaperone activity. Methods CellBiol. 50, 325–334.

ee, K.W., Cha, J.Y., Kim, K.H., Kim, Y.G., Lee, B.H., Lee, S.H., 2012. Overexpressionof alfalfa mitochondrial HSP23 in prokaryotic and eukaryotic model systemsconfers enhanced tolerance to salinity and arsenic stress. Biotechnol. Lett. 34,167–174.

os, D.A., Murata, N., 2004. Membrane fluidity and its roles in the perception ofenvironmental signals. Biochim. Biophys. Acta 1666, 142–157.

u, X.H., Sun, D.Q., Mo, Y.W., Xi, J.G., Sun, G.M., 2010. Effects of post-harvest salicylicacid treatment on fruit quality and anti-oxidant metabolism in pineapple duringcold storage. J. Hort. Sci. Biotechnol. 85, 454–458.

u, X., Sun, D., Li, Y., Shi, W., Sun, G., 2011. Pre- and post-harvest salicylic acidtreatments alleviate internal browning and maintain quality of winter pineapplefruit. Sci. Hortic. 130, 97–101.

uo, Z., Chen, C., Xie, J., 2011. Effect of salicylic acid treatment on alleviatingpostharvest chilling injury of ‘Qingnai’ plum fruit. Postharvest Biol. Technol. 62,115–120.

uo, Z., Wu, X., Xie, Y., Chen, C., 2012. Alleviation of chilling injury and brown-ing of postharvest bamboo shoot by salicylic acid treatment. Food Chem. 131,456–461.

yons, J.M., 1973. Chilling injury in plants. Annu. Rev. Plant. Physiol. 24, 445–466.ae, N., Makino, Y., Oshita, S., Kawagoe, Y., Tanaka, A., Aoki, K., Kurabayashi, A.,

Akihiro, T., Akama, K., Koike, S., Takayama, M., Matsukura, C., Ezura, H., 2012.Accumulation mechanism of gamma-aminobutyric acid in tomatoes (Solanumlycopersicum L) under low O2 with and without CO2. J. Agric. Food Chem. 60,1013–1019.

ao, L.-C., Wang, G.-Z., Zhu, C.-G., Pang, H.-Q., 2007a. Involvement of phospholipaseD and lipoxygenase in response to chilling stress in postharvest cucumber fruits.Plant Sci. 172, 400–405.

ao, L., Pang, H., Wang, G., Zhu, C., 2007b. Phospholipase D and lipoxygenase activityof cucumber fruit in response to chilling stress. Postharvest Biol. Technol. 44,42–47.

arangoni, A.G., Palma, T., Stanley, D.W., 1996. Membrane effects in postharvestphysiology. Postharvest Biol. Technol. 7, 193–217.

axwell, D.P., Wang, Y., McIntosh, L., 1999. The alternative oxidase lowers mito-chondrial reactive oxygen production in plant cells. Proc. Natl. Acad. Sci. U.S.A.96, 8271–8276.

eng, D., Song, T., Shen, L., Zhang, X., Sheng, J., 2012. Postharvest application ofmethyl jasmonate for improving quality retention of agaricus bisporus fruitbodies. J. Agric. Food Chem. 60, 6056–6062.

erodio, C., Munoz, M.T., Cura, B.D., Buitrago, D., Escribano, M., Isabel, í.a., 1998.Effect of high CO2 level on the titres of �-aminobutyric acid, total polyaminesand some pathogenesis-related proteins in cherimoya fruit stored at low tem-perature. J. Exp. Bot. 49, 1339–1347.

ittler, R., 2002. Oxidative stress antioxidants and stress tolerance. Trends PlantSci. 7, 405–410.

ittler, R., Vanderauwera, S., Gollery, M., Van Breusegem, F., 2004. Reactive oxygengene network of plants. Trends Plant Sci. 9, 490–498.

ittler, R., Zilinskas, B.A., 1992. Molecular cloning and characterization of a geneencoding pea cytosolic ascorbate peroxidase. J. Biol. Chem. 267, 21802–21807.

oller, I.M., 2001. Plant mitochondria and oxidative stress: electron transportnadph turnover, and metabolism of reactive oxygen species. Annu. Rev. Plant.
Physiol. Plant Mol. Biol. 52, 561–591.
orris Jr., S.M., 2009. Recent advances in arginine metabolism: roles and regulationof the arginases. Br. J. Pharmacol. 157, 922–930.

akamoto, H., Vigh, L., 2007. The small heat shock proteins and their clients. CellMol. Life Sci. 64, 294–306.


Neta-Sharir, I., Isaacson, T., Lurie, S., Weiss, D., 2005. Dual role for tomato heat shockprotein 21: protecting photosystem II from oxidative stress and promoting colorchanges during fruit maturation. Plant Cell 17, 1829–1838.

Nguyen, T.B.T., Ketsa, S., van Doorn, W.G., 2004. Effect of modified atmosphere pack-aging on chilling-induced peel browning in banana. Postharvest Biol. Technol.31, 313–317.

Niu, Y., Figueroa, P., Browse, J., 2011. Characterization of JAZ interacting bHLH tran-scription factors that regulate jasmonate responses in Arabidopsis. J. Exp. Bot.62, 2143–2154.

Panchuk, I.I., Volkov, R.A., Schoffl, F., 2002. Heat stress- and heat shock transcriptionfactor-dependent expression and activity of ascorbate peroxidase in Arabidop-sis. Plant Physiol. 129, 838–853.

Pinhero, R.G., Paliyath, G., Yada, R.Y., Murr, D.P., 1998. Modulation of phospholipaseD and lipoxygenase activities during chilling. Relation to chilling tolerance ofmaize seedlings. Plant Physiol. Biochem. 36, 213–224.

Promyou, S., Ketsa, S., van Doorn, W.G., 2012. Salicylic acid alleviates chilling injuryin anthurium (Anthurium andraeanum L) flowers. Postharvest Biol. Technol. 64,104–110.

Purvis, A.C., 1997. Role of the alternative oxidase in limiting superoxide productionby plant mitochondria. Physiol. Plant. 100, 165–170.

Rao, T.V.R., Gol, N.B., Shah, K.K., 2011. Effect of postharvest treatments and storagetemperatures on the quality and shelf life of sweet pepper (Capsicum annum L).Sci. Hortic. 132, 18–26.

Rinaldo, D., Mbéguié-A-Mbéguié, D., Fils-Lycaon, B., 2010. Advances on polyphenolsand their metabolism in sub-tropical and tropical fruits. Trend Food Sci. Technol.21, 599–606.

Rui, H., Cao, S., Shang, H., Jin, P., Wang, K., Zheng, Y., 2010. Effects of heat treatmenton internal browning and membrane fatty acid in loquat fruit in response tochilling stress. J. Sci. Food Agric. 90, 1557–1561.

Sala, J.M., 1998. Involvement of oxidative stress in chilling injury in cold-storedmandarin fruits. Postharvest Biol. Technol. 13, 255–261.

Sanchez-Ballesta, M.T., Zacarias, L., Granell, A., Lafuente, M.T., 2000. Accumulationof PAL transcript and PAL activity as affected by heat-conditioning and low-temperature storage and its relation to chilling sensitivity in mandarin fruits. J.Agric. Food Chem. 48, 2726–2731.

Sayyari, M., Babalar, M., Kalantari, S., Martínez-Romero, D., Guillén, F., Serrano, M.,Valero, D., 2011a. Vapour treatments with methyl salicylate or methyl jas-monate alleviated chilling injury and enhanced antioxidant potential duringpostharvest storage of pomegranates. Food Chem. 124, 964–970.

Sayyari, M., Babalar, M., Kalantari, S., Serrano, M., Valero, D., 2009. Effect of salicylicacid treatment on reducing chilling injury in stored pomegranates. PostharvestBiol. Technol. 53, 152–154.

Sayyari, M., Castillo, S., Valero, D., Díaz-Mula, H.M., Serrano, M., 2011b. Acetylsalicylic acid alleviates chilling injury and maintains nutritive and bioac-tive compounds and antioxidant activity during postharvest storage ofpomegranates. Postharvest Biol. Technol. 60, 136–142.

Schoffl, F., Prandl, R., Reindl, A., 1998. Regulation of the heat-shock response. PlantPhysiol. 117, 1135–1141.

Sevillano, L., Sanchez-Ballesta, M.T., Romojaro, F., Flores, F.B., 2009. Physiologicalhormonal and molecular mechanisms regulating chilling injury in horticulturalspecies. Postharvest technologies applied to reduce its impact. J. Sci. Food Agric.89, 555–573.

Shang, H., Cao, S., Yang, Z., Cai, Y., Zheng, Y., 2011. Effect of exogenousgamma-aminobutyric acid treatment on proline accumulation and chillinginjury in peach fruit after long-term cold storage. J. Agric. Food Chem. 59,1264–1268.

Sharom, M., Willemot, C., Thompson, J.E., 1994. Chilling injury induces lipid phasechanges in membranes of tomato fruit. Plant Physiol. 105, 305–308.

Sharp, R.E., Hsiao, T.C., Silk, W.K., 1990. Growth of the maize primary root at lowwater potentials II. Role of growth and deposition of hexose and potassium inosmotic adjustment. Plant Physiol. 93, 1337–1346.

Shelp, B.J., Bown, A.W., McLean, M.D., 1999. Metabolism and functions of gamma-aminobutyric acid. Trends Plant Sci. 4, 446–452.

Shewfelt, R.L., Purvis, A.C., 1995. Toward a comprehensive model for lipid peroxi-dation in plant tissue disorders. Hortscience 30, 213–218.

Sorger, P.K., Nelson, H.C., 1989. Trimerization of a yeast transcriptional activator viaa coiled-coil motif. Cell 59, 807–813.

Sun, J.-h., Chen, J.-y., Kuang, J.-f., Chen, W.-x., Lu, W.-j., 2010. Expression of sHSPgenes as affected by heat shock and cold acclimation in relation to chillingtolerance in plum fruit. Postharvest Biol. Technol. 55, 91–96.

Timperio, A.M., Egidi, M.G., Zolla, L., 2008. Proteomics applied on plant abioticstresses: role of heat shock proteins (HSP). J. Proteom. 71, 391–411.

Torok, Z., Goloubinoff, P., Horvath, I., Tsvetkova, N.M., Glatz, A., Balogh, G., Var-vasovszki, V., Los, D.A., Vierling, E., Crowe, J.H., Vigh, L., 2001. SynechocystisHSP17 is an amphitropic protein that stabilizes heat-stressed membranes andbinds denatured proteins for subsequent chaperone-mediated refolding. Proc.Natl. Acad. Sci. U.S.A. 98, 3098–3103.

Tsvetkova, N.M., Horvath, I., Torok, Z., Wolkers, W.F., Balogi, Z., Shigapova, N., Crowe,L.M., Tablin, F., Vierling, E., Crowe, J.H., Vigh, L., 2002. Small heat-shock pro-teins regulate membrane lipid polymorphism. Proc. Natl. Acad. Sci. U.S.A. 99,13504–13509.

Wang, L.-J., Li, S.-H., 2006. Salicylic acid-induced heat or cold tolerance in relationto Ca2+ homeostasis and antioxidant systems in young grape plants. Plant Sci.170, 685–694.

Wang, L., Chen, S., Kong, W., Li, S., Archbold, D.D., 2006. Salicylic acid pretreat-ment alleviates chilling injury and affects the antioxidant system and heat













































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































ntia H

W

W

X

Y

Y

Z


shock proteins of peaches during cold storage. Postharvest Biol. Technol. 41,244–251.

ang, W., Vinocur, B., Shoseyov, O., Altman, A., 2004. Role of plant heat-shockproteins and molecular chaperones in the abiotic stress response. Trends PlantSci. 9, 244–252.

ise, R.R., Naylor, A.W., 1987. Chilling-enhanced photophylls, chilling-enhancedphotooxidation—the peroxidative destruction of lipids during chilling injury tophotosynthesis and ultrastructure. Plant Physiol. 83, 272–277.

ue, Y., Peng, R., Xiong, A., Li, X., Zha, D., Yao, Q., 2009. Yeast heat-shock proteingene HSP26 enhances freezing tolerance in Arabidopsis. J. Plant Physiol. 166,844–850.

ang, A., Cao, S., Yang, Z., Cai, Y., Zheng, Y., 2011. �-Aminobutyric acid treatmentreduces chilling injury and activates the defence response of peach fruit. FoodChem. 129, 1619–1622.

ang, Z., Cao, S., Zheng, Y., Jiang, Y., 2012. Combined salicyclic acid and ultrasound
treatments for reducing the chilling injury on peach fruit. J. Agric. Food Chem.60, 1209–1212.
hang, J., Huang, W., Pan, Q., Liu, Y., 2005. Improvement of chilling tolerance andaccumulation of heat shock proteins in grape berries (Vitis vinifera cv Jingxiu)by heat pretreatment. Postharvest Biol. Technol. 38, 80–90.

orticulturae 156 (2013) 73–85 85

Zhang, X., Shen, L., Li, F., Meng, D., Sheng, J., 2011. Methyl salicylate-induced argininecatabolism is associated with up-regulation of polyamine and nitric oxide levelsand improves chilling tolerance in cherry tomato fruit. J. Agric. Food Chem. 59,9351–9357.

Zhang, X., Sheng, J., Li, F., Meng, D., Shen, L., 2012. Methyl jasmonate alters argininecatabolism and improves postharvest chilling tolerance in cherry tomato fruit.Postharvest Biol. Technol. 64, 160–167.

Zhao, D.Y., Shen, L., Fan, B., Liu, K.L., Yu, M.M., Zheng, Y., Ding, Y., Sheng, J.P., 2009.Physiological and genetic properties of tomato fruits from 2 cultivars differingin chilling tolerance at cold storage. J. Food Sci. 74, 348–352.

Zhao, M.L., Wang, J.N., Shan, W., Fan, J.G., Kuang, J.F., Wu, K.Q., Li, X.P., Chen,W.X., He, F.Y., Chen, J.Y., Lu, W.J., 2012. Induction of jasmonate signalingregulators MaMYC2s and their physical interactions with MaICE1 in methyljasmonate-induced chilling tolerance in banana fruit. Plant Cell Environ. 31,1365–3040.

Zhou, H.-W., Ben-Arie, R., Lurie, S., 2000. Pectin esterase, polygalacturonase and gelformation in peach pectin fractions. Phytochemistry 55, 191–195.

Zou, J., Liu, C., Liu, A., Zou, D., Chen, X., 2012. Overexpression of OsHsp17 0 andOsHsp23.7 enhances drought and salt tolerance in rice. J. Plant Physiol. 169,628–635.


























































































































































































































































































physiological and biochemical mechanisms regulating chilling tolerance in fruits and vegetables...

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