Herbivorous Livestock Research Institute, Chongqing Academy of Animal Sciences, Chongqing 402460, China.
Department of Grassland Science, Sichuan Agricultural University, Chengdu 611130, China.
Genes (Basel). 2021 Oct 28;12(11):1716. doi: 10.3390/genes12111716.
High-temperature stress negatively affects the growth and development of plants, and therefore threatens global agricultural safety. Cultivating stress-tolerant plants is the current objective of plant breeding programs. Pearl millet is a multi-purpose plant, commonly used as a forage but also an important food staple. This crop is very heat-resistant and has a higher net assimilation rate than corn under high-temperature stress. However, the response of heat resistant pearl millet has so far not been studied at the transcriptional level. In this study, transcriptome sequencing of pearl millet leaves exposed to different lengths of heat treatment (1 h, 48 h and 96 h) was conducted in order to investigate the molecular mechanisms of the heat stress response and to identify key genes related to heat stress. The results showed that the amount of heat stress-induced DEGs in leaves differs with the length of exposure to high temperatures. The highest value of DEGs (8286) was observed for the group exposed to heat stress for 96 h, while the other two treatments showed lower DEGs values of 4659 DEGs after 1 h exposure and 3981 DEGs after 48 h exposure to heat stress. The DEGs were mainly synthesized in protein folding pathways under high-temperature stress after 1 h exposure. Moreover, a large number of genes encoding ROS scavenging enzymes were activated under heat stress for 1 h and 48 h treatments. The flavonoid synthesis pathway of pearl millet was enriched after heat stress for 96 h. This study analyzed the transcription dynamics under short to long-term heat stress to provide a theoretical basis for the heat resistance response of pearl millet.
高温胁迫会对植物的生长和发育产生负面影响，从而威胁到全球农业安全。培育抗逆植物是当前植物育种计划的目标。珍珠粟是一种多用途植物，通常用作饲料，但也是一种重要的粮食作物。这种作物非常耐热，在高温胁迫下比玉米具有更高的净同化率。然而，耐热珍珠粟的耐热响应在转录水平上尚未得到研究。在这项研究中，对暴露于不同时长热处理（1 h、48 h 和 96 h）的珍珠粟叶片进行了转录组测序，以研究热胁迫响应的分子机制，并鉴定与热胁迫相关的关键基因。结果表明，叶片中热应激诱导的差异表达基因（DEGs）的数量随高温暴露时间的长短而不同。暴露于 96 h 热应激的组观察到最高数量的 DEGs（8286 个），而其他两个处理组在暴露于 1 h 和 48 h 热应激后分别观察到 4659 个 DEGs 和 3981 个 DEGs。在 1 h 高温胁迫下，DEGs 主要在蛋白质折叠途径中合成。此外，在 1 h 和 48 h 的热应激处理下，大量编码 ROS 清除酶的基因被激活。在 96 h 的热应激后，珍珠粟的类黄酮合成途径被富集。本研究分析了短期到长期热胁迫下的转录动态，为珍珠粟的耐热响应提供了理论依据。
