A bHLH transcription factor,CsSPT,regulates high-temperature resistance in cucumber  

作　　者：Yonggui Liang Chenyu Yang Fangyan Ming Bingwei Yu Zhihua Cheng Yixi Wang Zhengkun Qiu Xiaolan Zhang Bihao Cao Shuangshuang Yan 

机构地区：[1]Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(South China),Ministry of Agriculture and Rural Affairs,Guangdong Vegetable Engineering and Technology Research Center,College of Horticulture,South China Agricultural University,Guangzhou,Guangdong 510642,China [2]State Key Laboratories of Agrobiotechnology,Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops,MOE Joint Laboratory for International Cooperation in Crop Molecular Breeding,China Agricultural University,Beijing 100193,China

出　　处：《Horticultural Plant Journal》2024年第2期503-514,共12页园艺学报（英文版）

基　　金：supported by grants from the Key Project of Guangzhou (Grant No.202103000085);National Natural Science Foundation of China (Grant No.31902014);Guangzhou Science and Technology Project (Grant No.202102020502);Fruit and Vegetable Industry System Innovation Team Project of Guangdong (Grant No.2021KJ110)。

摘　　要：High-temperature stress threatens the growth and yield of crops. Basic helix-loop-helix(bHLH) transcription factors(TFs) have been shown to play important roles in regulating high-temperature resistance in plants. However, the bHLH TFs responsible for high-temperature tolerance in cucumbers have not been identified. We used transcriptome profiling to screen the high temperature-responsive candidate bHLH TFs in cucumber. Here, we found that the expression of 75 CsbHLH genes was altered under high-temperature stress. The expression of the CsSPT gene was induced by high temperatures in TT(Thermotolerant) cucumber plants. However, the Csspt mutant plants obtained by the CRISPR-Cas9 system showed severe thermosensitive symptoms, including wilted leaves with brown margins and reduced root density and cell activity.The Csspt mutant plants also exhibited elevated H_(2)O_(2) levels and down-regulated photosystem-related genes under normal conditions.Furthermore, there were high relative electrolytic leakage(REC), malondialdehyde(MDA), glutathione(GSH), and superoxide radical(O_(2)^(·-)) levels in the Csspt mutant plants, with decreased Proline content after the high-temperature treatment. Transcriptome analysis showed that the photosystem and chloroplast activities in Csspt mutant plants were extremely disrupted by the high-temperature stress compared with wildtype(WT) plants. Moreover, the plant hormone signal transduction, as well as MAPK and calcium signaling pathways were activated in Csspt mutant plants under high-temperature stress. The HSF and HSP family genes shared the same upregulated expression patterns in Csspt and WT plants under high-temperature conditions. However, most bHLH, NAC, and bZIP family genes were significantly down-regulated by heat in Csspt mutant plants. Thus, these results demonstrated that CsSPT regulated the high-temperature response by recruiting photosynthesis components, signaling pathway molecules, and transcription factors. Our results provide important insights into the heat response

关 键 词：CUCUMBER BHLH CsSPT PHOTOSYNTHESIS High temperature 

分 类 号：S642.2[农业科学—蔬菜学]