Effects of cucumber mosaic virus infection on electron transport and antioxidant system in chloroplasts and mitochondria of cucumber and tomato leaves.
We examined the responses of the photosynthetic and respiratory electron transport and antioxidant systems in cell organelles of cucumber (Cucumis sativus L.) and tomato (Lycopersicon esculentum Mill.) leaves to infection of cucumber mosaic virus (CMV) by comparing the gas exchange, Chl fluorescence, respiratory electron transport, superoxide dismutase (SOD, EC 1.15.1.1) and ascorbate-glutathione (AsA-GSH) cycle enzymes and the production of H(2)O(2) in chloroplasts, mitochondria and soluble fraction in virus-infected and non-infected leaves. Long-term CMV infection resulted in decreased photosynthesis and respiration rates. Photosynthetic electron flux to carbon reduction, respiratory electron transport via both complex I and complex II and also the Cyt respiration rate all significantly decreased, while photosynthetic alternative electron flux and alternative respiration significantly increased. These changes in electron transport were accompanied by a general increase in the activities of SOD/AsA-GSH cycle enzymes followed by an increased H(2)O(2) accumulation in chloroplasts and mitochondria. These results demonstrated that disturbance of photosynthetic and respiratory electron transport by CMV also affected the antioxidative systems, thereby leading to oxidative stress in various organelles.
Song
Xing-Shun
XS
Department of Horticulture, Zhejiang University, Hangzhou, China.
Wang
Yan-Jie
YJ
Mao
Wei-Hua
WH
Shi
Kai
K
Zhou
Yan-Hong
YH
Nogués
Salvador
S
Yu
Jing-Quan
JQ
D000975:Antioxidants / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D018553:Cucumis sativus / Q000378:metabolism / Q000821:virology*; D017799:Cucumovirus / Q000472:pathogenicity*; D004579:Electron Transport; D005453:Fluorescence; D006861:Hydrogen Peroxide / Q000378:metabolism; D018551:Solanum lycopersicum / Q000378:metabolism / Q000821:virology*; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress; D010788:Photosynthesis; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000378:metabolism / Q000821:virology; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D002734:Chlorophyll; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase