Imaging viral infection: studies on Nicotiana benthamiana plants infected with the pepper mild mottle tobamovirus.
We have studied by kinetic Chl-fluorescence imaging (Chl-FI) Nicotiana benthamiana plants infected with the Italian strain of the pepper mild mottle tobamovirus (PMMoV-I). We have mapped leaf photosynthesis at different points of the fluorescence induction curve as well as at different post-infection times. Images of different fluorescence parameters were obtained to investigate which one could discriminate control from infected leaves in the absence of symptoms. The non-photochemical quenching (NPQ) of excess energy in photosystem II (PSII) seems to be the most adequate chlorophyll fluorescence parameter to assess the effect of tobamoviral infection on the chloroplast. Non-symptomatic mature leaves from inoculated plants displayed a very characteristic time-varying NPQ pattern. In addition, a correlation between NPQ amplification and virus localization by tissue-print was found, suggesting that an increase in the local NPQ values is associated with the areas invaded by the pathogen. Changes in chloroplast ultrastructure in non-symptomatic leaf areas showing different NPQ levels were also investigated. A gradient of ultrastructural modifications was observed among the different areas.
Pérez-Bueno
María Luisa
ML
Plant Biology Department, Centro Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, Madrid, 28040, Spain.
Ciscato
Massimo
M
VandeVen
Martin
M
García-Luque
Isabel
I
Valcke
Roland
R
Barón
Matilde
M
D000914:Antibodies, Viral / Q000276:immunology; D036022:Capsid Proteins / Q000276:immunology; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D010788:Photosynthesis; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000648:ultrastructure / Q000821:virology; D013997:Time Factors; D014026:Nicotiana / Q000648:ultrastructure / Q000821:virology*; D017898:Tobamovirus / Q000276:immunology / Q000502:physiology* / Q000648:ultrastructure
D000914:Antibodies, Viral; D036022:Capsid Proteins