Dong Cuina, Peng Xixuan, Yang Xiaona, Wang Chenggang, Yuan Lingyun, Chen Guohu, Tang Xiaoyan, Wang Wenjie, Wu Jianqiang, Zhu Shidong, Huang Xingxue, Zhang Jinlong, Hou Jinfeng
Vegetable Genetics and Breeding Laboratory, College of Horticulture, Anhui Agricultural University, 130 West Changjiang Road, Hefei 230036, China.
Provincial Engineering Laboratory for Horticultural Crop Breeding of Anhui, 130 West of Changjiang Road, Hefei 230036, China.
Plants (Basel). 2024 Apr 13;13(8):1093. doi: 10.3390/plants13081093.
High temperatures have adverse effects on the yield and quality of vegetables. Bok choy, a popular vegetable, shows varying resistance to heat. However, the mechanism underlying the thermotolerance of bok choy remains unclear. In this study, 26 bok choy varieties were identified in screening as being heat-resistant at the seedling stage; at 43 °C, it was possible to observe obvious heat damage in different bok choy varieties. The physiological and biochemical reactions of a heat-tolerant cultivar, Jinmei (J7), and a heat-sensitive cultivar, Sanyueman (S16), were analyzed in terms of the growth index, peroxide, and photosynthetic parameters. The results show that Jinmei has lower relative conductivity, lower peroxide content, and higher total antioxidant capacity after heat stress. We performed transcriptome analysis of the two bok choy varieties under heat stress and normal temperatures. Under heat stress, some key genes involved in sulfur metabolism, glutathione metabolism, and the ribosome pathway were found to be significantly upregulated in the heat-tolerant cultivar. The key genes of each pathway were screened according to their fold-change values. In terms of sulfur metabolism, genes related to protease activity were significantly upregulated. Glutathione synthetase () in the glutathione metabolism pathway and the , , and genes in the ribosomal pathway were significantly upregulated in heat-stressed cultivars. These results suggest that the total antioxidant capacity and heat injury repair capacity are higher in Jinmei than in the heat-sensitive variety, which might be related to the specific upregulation of genes in certain metabolic pathways after heat stress.
高温对蔬菜的产量和品质有不利影响。小白菜是一种常见蔬菜，对热的耐受性存在差异。然而，小白菜耐热性的潜在机制尚不清楚。在本研究中，26个小白菜品种在苗期筛选中被鉴定为耐热品种；在43℃时，可以观察到不同小白菜品种有明显的热损伤。从生长指标、过氧化物和光合参数方面分析了耐热品种金美（J7）和热敏品种三月慢（S16）的生理生化反应。结果表明，热胁迫后金美的相对电导率较低、过氧化物含量较低、总抗氧化能力较高。我们对两个小白菜品种在热胁迫和常温下进行了转录组分析。在热胁迫下，发现参与硫代谢、谷胱甘肽代谢和核糖体途径的一些关键基因在耐热品种中显著上调。根据其倍数变化值筛选各途径的关键基因。在硫代谢方面，与蛋白酶活性相关的基因显著上调。谷胱甘肽代谢途径中的谷胱甘肽合成酶（）以及核糖体途径中的、和基因在热胁迫品种中显著上调。这些结果表明，金美的总抗氧化能力和热损伤修复能力高于热敏品种，这可能与热胁迫后某些代谢途径中基因的特异性上调有关。
