LeCDJ1, a chloroplast DnaJ protein, facilitates heat tolerance in transgenic tomatoes

• Published in: Journal of integrative plant biology Vol. 56; no. 1; pp. 63 - 74
• Main Authors: Kong, Fanying, Deng, Yongsheng, Wang, Guodong, Wang, Jieru, Liang, Xiaoqing, Meng, Qingwei
• Format: Journal Article
• Language: English
• Published: China (Republic : 1949- ) Blackwell Publishing Ltd 2014; College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an, Shandong 271018, China
• Subjects: abscisic acid; Adaptation, Physiological - drug effects; Adaptation, Physiological - genetics; ascorbate peroxidase; Ascorbate Peroxidases - metabolism; Chlorophyll - metabolism; Chloroplasts - drug effects; Chloroplasts - metabolism; D1 protein; DnaJ protein; Electric Conductivity; electrical conductivity; Gene Expression Regulation, Plant - drug effects; gene overexpression; heat stress; heat tolerance; Heat-Shock Response - drug effects; Heat-Shock Response - genetics; Hot Temperature; HSP40 Heat-Shock Proteins - genetics; HSP40 Heat-Shock Proteins - metabolism; hydrogen peroxide; Lycopersicon esculentum; Lycopersicon esculentum - enzymology; Lycopersicon esculentum - genetics; Lycopersicon esculentum - growth & development; Lycopersicon esculentum - physiology; Malondialdehyde - metabolism; oxygen; paraquat; photoinhibition; photosystem II; Photosystem II Protein Complex - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified; protective effect; protein synthesis; PSII; reactive oxygen species; Reactive Oxygen Species - metabolism; Real-Time Polymerase Chain Reaction; Seedlings - genetics; Seedlings - physiology; sodium chloride; Solanum lycopersicum var. lycopersicum; streptomycin; Streptomycin - pharmacology; Stress, Physiological - genetics; superoxide dismutase; Superoxide Dismutase - metabolism; tomato; tomatoes; 叶绿体; 抗坏血酸过氧化物酶; 热耐受性; 蛋白水平; 超氧化物歧化酶; 转基因番茄; 转基因西红柿; heat stress; photosystem II; tomato; D1 protein; DnaJ protein; reactive oxygen species
• ISSN: 1672-9072; 1744-7909
• DOI: 10.1111/jipb.12119

The roles of a tomato （Lycopersicon esculentum） chloroplast-targeted DnaJ protein （LeCDJ1） were investigat-ed using wild-type （WT） and sense transgenic tomatoes. The LeCDJ1 expression was upregulated by 38℃, 42 ℃, 45 ℃, NaCl, PEG, methyl viologen （MV） and hydrogen peroxide （H2O2）, but not by 30 ℃ and 35 ℃. Meanwhile, LeCDJ1 was involved in the response of plants to abscisic acid （ABA）. Under heat stress, the sense plants showed better growth, higher chlorophyll content, lower malondialdehyde （MDA） accumulation and relative electrical conductivity （REC）, and also less PSII photoinhibition than WT. Interestingly, the sense plants treated with streptomycin （SM）, an inhibitor of organellar translation, still showed higher maximum photo-chemistry efficiency of PSII （Fv/Fm） and D1 protein levels than the SM-untreated WT, suggesting that the protective effect of LeCDJ1 on PSII was, at least partially, independent of D1＆amp;nbsp;protein synthesis. Furthermore, the relatively lower super-oxide radical （O2^＊-） and H2O2 levels in the sense plants were considered to be due to the higher ascorbate peroxidase （APX） and superoxide dismutase （SOD） activity, which seemed unlikely dependent on their transcription level. These results indicated that LeCDJ1 overexpression facilitated heat tolerance in transgenic tomatoes.