ULTRASTRUCTURAL CHANGES OF CHLOROPLASTS CAUSED BY TOBAMOVIRUS

INFECTIONS IN DIFFERENT PEPPER VARIETIESRichard Gáborjányi1 Asztéria Almási2, Éva Sárvári3, Károly Bóka4,

Rita Lózsa4 and Zsolt Sági5

1Georgicon Faculty of Agricultural Sciences, Pannon University Veszprém; 2Plant Protection Institute, Hungarian Academy of Sciences, Budapest, 3Department of Plant Physiology Eötvös Loránd

University, Budapest, 4Department of Plant Anatomy, Eötvös Loránd University, Budapest, 5Research Institute for Vegetable Breeding, Budapest

Opatija, 6-11 March 2006

Virus infections often reduce the photosynthetic activity, causing growth inhibition, dwarfing and severe yield losses

A dohány mozaik vírus (TMV) tünetei dohányon

Mosaic and mottling are the most characteristic symptoms of virus infections indicating the serious damages of photosynthetic structure of chloroplasts

In this experiments we were curious to know, how different Tobamoviruses can influence the chloroplast structure of pepper (Capsicum annuum) varieties with different levels susceptibility

Obuda pepper mosaic virus

ObPMV

Pepper Mild Mottle Virus

PMMV-I

Fig. 8. Chloroplast of a healthy pepper (Capsicum annuum cv. Paradicsom alakú szentesi) leaf B: Membrane; G: Grana; IC: Intercellular space; P: Plastoglobuli; SF: Cell wall; V: Vacuole

Fig 9. Chloroplast from the green area of PMMV-I infected Boni pepper leaf. Deformed shape and thilacoid dilatations shows the slight damage of green areas. B: membrane G: grana; IC: intercellular space; P: plastoglobuli; SF: cell wall; V: vacuole

Fig 10. Cells from the yellow area of PMMV-I infected Boni paprika leaf. Beside the heavily degraded cells relatively intact cells with well organized grana . B: membrane; G: grana; P: plastoglobuli; SF: cell wall; V: vacuoles; VI: virion clusters

Fig.11. Increased granal structure of chloroplast from the green area of PMMV-I- infected pepper (Paradicsom alakú szentesi) leaves. B: Membrane; G: Grana; IC: Intercellular space; P: Plastoglobuli; SF: Cell wall; V: Vacuolum.

Fig 12. Chloroplast from ObPV-infected yellow segments of pepper leaf (variety Boni). B: membrane; G: granum; P: plastoglobuli; SF: cell wall; V: vacuole.

Fig.13 Chloroplast from the yellow area of ObPV-infected pepper (Paradicsom alakú szentesi) leaf. Swollen chloroplasts with disintegrated thilacoid membranes and lot of vesicles B: membrane; G: granum; IC: intercellullar space; P: plastoglobuli; SF: cell wall; V: vacuole

;

Fig. 3. Desintegrated chloroplast from the yellow area of PMMV-I-infected pepper (Capsicum annuum. cv. Paradicsom alakú szentesi) leaves. Plastids are swollen, thylacoid structure is desintegrated, grana show spindle forms, plastoglobuli forme clusters. B: Membrane; G: Grana; IC: Intercellular space; P:Plastoglobuli; SF: Cell wall; V: Vacuolum

Fig 14. Chloroplast from the yellow area of ObPV-infected pepper (Boni) leaf. Note the swollen chloroplasts with disintegrated thilacoid membranes and a lot of vesicles B: membrane; G: granum; IC: intercellular space; P: plastoglobuli; SF: cell wall; V: vacuole

Fig.15 Chloroplast from the green area of ObPV-infected leaf of Paradicsom alakú szentesi pepper. Chloroplast contain high granal structures with bright plastoglobuli. G: grana; P: plastoglobuli; SF: cell wall; V: vacuole; VI: virion aggregation

Conclusions (I)

Virus infection caused degradation of chloroplast structures with different levels of severity

Severity of symptoms was in good connection with the resistance of the used pepper varieties and the pathogenicity of the virus species

Conclusions (2)

Chloroplasts of the „yellow areas” suffered more from virus infection than the „green ones”

Slight increase of granal structure was observed in the „green tissues” giving an alternative to the plant to survive the virus infection

A klorofill-protein komplexek elhelyezkedése a fotoszintetikus membránban