Chloroplastic thioredoxin-f and thioredoxin-m1/4 play important roles in brassinosteroids-induced changes in CO2 assimilation and cellular redox homeostasis in tomato.
Chloroplast thioredoxins (TRXs) and glutathione function as redox messengers in the regulation of photosynthesis. In this work, the roles of chloroplast TRXs in brassinosteroids (BRs)-induced changes in cellular redox homeostasis and CO2 assimilation were studied in the leaves of tomato plants. BRs-deficient d (^im) plants showed decreased transcripts of TRX-f, TRX-m2, TRX-m1/4, and TRX-x, while exogenous BRs significantly induced CO2 assimilation and the expression of TRX-f, TRX-m2, TRX-m1/4, and TRX-x. Virus-induced gene silencing (VIGS) of the chloroplast TRX-f, TRX-m2, TRX-m1/4, and TRX-y genes individually increased membrane lipid peroxidation and accumulation of 2-Cys peroxiredoxin dimers, and decreased the activities of the ascorbate-glutathione cycle enzymes and the ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) in the leaves. Furthermore, partial silencing of TRX-f, TRX-m2, TRX-m1/4, and TRX-y resulted in decreased expression of genes involved in the Benson-Calvin cycle and decreased activity of the associated enzymes. Importantly, the BRs-induced increase in CO2 assimilation and the increased expression and activities of antioxidant- and photosynthesis-related genes and enzymes were compromised in the partially TRX-f- and TRX-m1/4-silenced plants. All of these results suggest that TRX-f and TRX-m1/4 are involved in the BRs-induced changes in CO2 assimilation and cellular redox homeostasis in tomato.
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
Fei
F
Cheng
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China yanhongzhou@zju.edu.cn jqyu@zju.edu.cn.
Yan-Hong
YH
Zhou
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
Xiao-Jian
XJ
Xia
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
Kai
K
Shi
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China.
Jie
J
Zhou
Department of Horticulture, Zijingang Campus, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058, PR China Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Yuhangtang Road 866, Hangzhou, 310058, PR China yanhongzhou@zju.edu.cn jqyu@zju.edu.cn.
Jing-Quan
JQ
Yu
D001205:Ascorbic Acid / Q000378:metabolism; D060406:Brassinosteroids / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D054479:Chloroplast Thioredoxins / Q000378:metabolism*; D020868:Gene Silencing; D005978:Glutathione / Q000378:metabolism; D006706:Homeostasis; D018551:Solanum lycopersicum / Q000378:metabolism*; D010084:Oxidation-Reduction; D010788:Photosynthesis
D060406:Brassinosteroids; D054479:Chloroplast Thioredoxins; D002245:Carbon Dioxide; D005978:Glutathione; D001205:Ascorbic Acid
2-Cys peroxiredoxin; Antioxidant; Benson–Calvin cycle; chloroplast; glutathione; photosynthesis.