Imaging viral infection. Studies on Nicotiana benthamiana plants infected with the pepper mild mottle tobamovirus. Pérez Bueno, María Luisa Ciscato, M vandeVen, M García-Luque, I Valcke, R Barón, M 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. 2025-02-02T10:13:25Z 2025-02-02T10:13:25Z 2007-01-03 journal article https://hdl.handle.net/10481/101782 10.1007/S11120-006-9098-0 eng embargoed access