by emily keator and phoebe parrish
DESCRIPTION
By Emily Keator and Phoebe Parrish. : Part. 04-17-14. What Does Iron Do? . Highly reactive—involved in many redox reactions Involved in photosynthesis & cellular respiration as part of the ETC Toxic in high amounts. Uptake Genes. AHA Extrudes H + ions FRO2 Reduces Fe 3+ → Fe 2+ - PowerPoint PPT PresentationTRANSCRIPT
By Emily Keator and Phoebe Parrish
: Part04-17-14
What Does Iron Do?
• Highly reactive—involved in many redox reactions
• Involved in photosynthesis & cellular respiration as part of the ETC
• Toxic in high amounts
Uptake Genes
• AHAo Extrudes H+ ions
• FRO2o Reduces Fe3+ → Fe2+
• IRT1o Transports Fe2+ into cell (regulated by ubiquitin)o Also involved in uptake of other heavy metal
cations
Transport Genes
• YSL1&2 o Influx (phloem)o Transport Fe-NA complexes
• FRD3 (MATE efflux family proteins)o Efflux (xylem)o Transport Fe-citrate complexes; provide shoots with
usable forms of Fe
Storage Genes
• Ferritino Complexes Fe2+ molecules togethero Stores readily-usable form of Fe in vacuoles &
amyloplasts
• PIC1o Transports Fe into chloroplasts
• IREG1o Moves Fe into vacuole
Regulatory Genes
• bHLH38,39,100&101o Regulate IRT1 and FRO2 genes
• FIT1o Forms heterodimers with bHLH → control
transcription of Fe uptake genes
• Both transcribed when Fe deficiency is sensed in the roots
QTLs
C01 1,923,307
C03 13,636,922
C05 43,302,017
C08 33,379,515
C09-1 3,558,943
C09-2 45,002,150
BLAST Results
C01
QTL C01: 1,923,307
AHA1,2,9: 4,691,639*
IRT1: 3,007,445*
YSL2: 11,431,126*YSL1: 11,431,687
FIT1: 6,411,902*
0
+10,000,000
C03
-10,000,000
+10,000,000
AHA1,2,9: 19,835,760*
QTL C03: 13,636,922FRD3: 12,416,349*
FIT1: 16,455,349*
QTL* = confirmed w/ IGBQuestionable presence on IGB
C05
-10,000,000
+10,000,000
AHA1,2,9: 43,882,387*QTL C05: 43,302,017
IRT1: 41,537,794*
FRD3: 43,624,447*
FPN1/IREG1:34,728,143
FER1: 42,532,200*
FIT1: 39,453,920
C08
-10,000,000
+10,000,000
QTL C08: 33,379,515AHA1,2,9: 32,394,505*
FRO1,2: 41,520,823*
IRT1:39,033,254*
FER1:30,370,173*bHLH38&39: 30,863,851*bHLH100&101: 30,878,266, 30,890,636*
QTL* = confirmed w/ IGBQuestionable presence on IGB
C09
-10,000,000
+10,000,000
QTL C09-2: 45,002,150
AHA1,2,9:40,597,697*
IRT1: 49,050,708*
YSL1: 40,697,628
YSL2: 36,138,179*
QTL* = confirmed w/ IGBQuestionable presence on IGB
QTL C09-1: 3,558,943
AHA1, AHA2: 514,992*
AHA9: 8,682,603*
FRO1: 137,473*
YSL1,2: 1,879,450*
PIC1: 7,315,088*
+10,000,000
0
C09
IGB Results
C01 QTL C01: 1,923,307
2,114,850: Heavy metal transport/detoxification superfamily protein^
3,007,445 (ZIP9)^
-1,000,000
+1,000,000
QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method
● ZIP9 (homolog of IRT3)○ Location: nucleus, plasmodesma○ Expression: petal differentiation & expansion stage○ Function: transports zinc and other cations; contains
zinc/iron permease domain● Heavy metal transport/detoxification
superfamily protein○ Location: nucleus, plasmodesma○ Expression: petal differentiation and expansion stage○ Function: metal ion transport and binding
Confirmed BLAST resultGenes found only on IGB
C03 QTL C03: 13,636,922
12,418,215: Multidrug resistance protein^
12,415,632: MATE efflux family protein (FRD3)^
-1,200,000
+1,200,000
QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method
• FRD3 (MATE efflux family protein)o Location: plasma membrane o Expression: petal differentiation & expansion stageo Function: iron-citrate transport
• MdtK (multidrug resistance protein)o Location: chloroplast & plasma membraneo Expression: petal differentiation & expansion stage o Function: ion transporter/antiporter activity
Confirmed BLAST resultGenes found only on IGB
C05 QTL C05: 43,302,017
42,532,200: ferritin (FER1)^
42,731,745: Heavy metal transport/detoxification superfamily protein^
-1,000,000
+1,000,000
43,536,616: MATE efflux family protein (FRD3)^
43,624,447: MATE efflux family protein (FRD3)^
41,537,794: zinc transporter (IRT1)^
QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method
43,882,387: calcium transporting ATPase^
• IRT1o Location: membraneo Expression: petal differentiation & expansion stageo Function: cellular response to iron ion starvation, iron transport, etc.
• FER1o Location: chloroplasto Expression: petal differentiation & expansiono Function: iron ion transport and homeostasis, ferric iron binding
• Heavy metal transport/detoxification (homolog of ATX1)o Location: plasma membraneo Expression: pollen, petal, petioleo Function: metal ion transport & binding
• FRD3 (MATE efflux family protein)o Location: plasma membraneo Expression: roots, flower, petioleo Function: iron ion and citrate transport & homeostasis
Confirmed BLAST resultGenes found only on IGB
C08 QTL C08: 33,379,515
32,394,505: H+-ATPase (AHA)
33,828,404: Ferrochelatase
-1,000,000
+1,000,000
QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method
• AHA (H+-ATPase)o Location: plasma membrane, Golgi apparatus,
vacuolar membraneo Expression: petal differentiation & expansiono Function: ion transport
• Ferrochelataseo Location: chloroplasto Expression: petal differentiation & expansiono Function: terminal enzyme of heme biosynthesis
Confirmed BLAST resultGenes found only on IGB
QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method
C09 QTL C09-1: 3,558,943
3,501,200: Ferrochelatase^
-1,000,000
+1,000,000
C09
-1,000,000
+1,000,000
QTL C09-2: 45,002,150
45,568,877: MATE efflux family protein
45,927,322: heavy metal transport/detoxification superfamily protein
QTLConfirmed BLAST resultGenes found only on IGB^ = gene identified through BLAST/TAIR method
• MATE efflux family protein o Location: (?)o Expressed in: (?)o Function: transport
• Heavy metal transport/detoxification superfamily proteino Location: extracellular space (?)o Expression: petal differentiation & expansiono Function: exact function unknown
Confirmed BLAST resultGenes found only on IGB
Conclusions• IGB contained almost all genes found on
BLAST• Used IGB to confirm genes found on BLAST
(+/- 1,000,000 bp)• IGB yielded several new candidates (more
speculative)• Overall: a number of good candidate genes,
close to QTL and expressed in relevant tissues
ReferencesBarberon M et al. Monoubiquitin-dependent endocytosis of the iron-regulated transporter 1 (IRT1) transporter controls iron uptake in plants.
PNAS, 2011. 108(32):E450-E458.
Briat, JF et. al. Regulation of plant ferritin synthesis: how and why. Cellular and Molecular Life Sciences, 1999. 56:155-166.
Grotz, N et. al. Molecular aspects of Cu, Fe, and Zn homeostasis in plants. Biochemica et Biophysica Acta, 2006. 1763:595-608.
Harper JF et al. The Arabidopsis thaliana plasma membrane H+-ATPase multigene family. The Journal of Biological Chemistry, 1990. 265(23):13601-13608.
Hell, R et. al. Iron uptake, trafficking, and homeostasis in plants. Planta, 2003. 216:541-551.
Kim, S et. al. Mining iron: iron uptake and transport in plants. FEBS Letters, 2007. 581:2273-2280.
Kobayashi T, Nishizawa NK. Iron uptake, translocation, and regulation in higher plants. Annual Review of Plant Biology, 2012. 63:131-52.
Matsuoka, K et. al. Gibberellin-induced expression of Fe uptake-related genes in Arabidopsis. Plant Cell Physiol., 2014. 55(1):87-98.
Robinson, NJ et. al. A ferric-chelate reductase for iron uptake from soil. Nature, 1999. 397:694-697.
Roschzttardtz, H et. al. New insights into Fe localization in plant tissues. Frontiers In Plant Science, 2013. 4:1-11.
Seo, PJ et. al. A golgi-localized MATE transporter mediates iron homeostasis under osmotic stress in Arabidopsis. BIochemical Journal, 2012. 442:551-561.
Sussman MR. Molecular analysis of proteins in the plant plasma membrane. Annual Review of Plant Physiology and Plant Molecular Biology, 1994. 45:211-34.
Vert, G et. al. IRT1, an Arabidopsis transporter essential for iron uptake from the soil and for plant growth. The Plant Cell, 2002. 14:1223-1233.