title: Decreased Biosynthesis of Jasmonic Acid via Lipoxygenase Pathway Compromised Caffeine-Induced Resistance to Colletotrichum gloeosporioides Under Elevated CO2in Tea Seedlings.
abstract: Caffeine, the major purine alkaloid in tea has long been known for its role in plant defense. However, its effect on Colletotrichum gloeosporioides that causes brown blight disease in tea is largely unknown especially under elevated CO2. Here we show that elevated CO2reduced endogenous caffeine content in tea leaves, but sharply increased susceptibility of tea to C. gloeosporioides. The expression of C. gloeosporioides actin gene was gradually increased during the postinoculation period. In contrast, foliar application of caffeine decreased the C. gloeosporioides-induced necrotic lesions and the expression of C. gloeosporioides actin. Analysis of endogenous jasmonic acid (JA) content revealed that exogenous caffeine could induce JA content under both CO2conditions in absence of fungal infection; however, in presence of fungal infection, caffeine increased JA content only under elevated CO2. Furthermore, exogenous caffeine enhanced lipoxygenase (LOX) activity and its biosynthetic gene expression under both CO2conditions, indicating that increased JA biosynthesis via LOX pathway by caffeine might strengthen plant defense only under elevated CO2, while caffeine-induced defense under ambient CO2might be associated with JA-independent LOX pathway in tea. These results provide novel insights into caffeine-induced plant defense mechanisms that might help to develop an eco-friendly approach for disease control.
authors.affiliation: All authors: Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, P.R. China; first, fourth, fifth, and six authors: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 Meiling Road, Hangzhou, 310008, P.R. China and second author: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: All authors: Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, P.R. China; first, fourth, fifth, and six authors: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 Meiling Road, Hangzhou, 310008, P.R. China and second author: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Golam Jalal
authors.identifier: 0000-0001-9621-8431
authors.initials: GJ
authors.lastname: Ahammed
authors.affiliation: All authors: Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, P.R. China; first, fourth, fifth, and six authors: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 Meiling Road, Hangzhou, 310008, P.R. China and second author: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Li
authors.affiliation: All authors: Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, P.R. China; first, fourth, fifth, and six authors: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 Meiling Road, Hangzhou, 310008, P.R. China and second author: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Meijun
authors.initials: M
authors.lastname: Tang
authors.affiliation: All authors: Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, P.R. China; first, fourth, fifth, and six authors: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 Meiling Road, Hangzhou, 310008, P.R. China and second author: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Yan
authors.affiliation: All authors: Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, P.R. China; first, fourth, fifth, and six authors: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 Meiling Road, Hangzhou, 310008, P.R. China and second author: Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
authors.forename: Wenyan
authors.initials: W
authors.lastname: Han
mesh_terms: D002110:Caffeine / Q000378:metabolism / Q000494:pharmacology*; D028241:Camellia sinensis / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D002245:Carbon Dioxide / Q000494:pharmacology; D020231:Colletotrichum / Q000472:pathogenicity*; D003517:Cyclopentanes / Q000378:metabolism*; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D058945:Lipoxygenases / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D010937:Plant Growth Regulators / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000276:immunology / Q000382:microbiology
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D002245:Carbon Dioxide; D002110:Caffeine; C011006:jasmonic acid; D058945:Lipoxygenases
keywords: Camellia sinensis; climate change; foliar disease