Institute of qinghai-tibetan Plateau, Southwest Minzu University, Chengdu, 610041, China.
Sichuan Grass Industry Technology Research and Promotion Center, Chengdu, 610041, China.
BMC Genomics. 2022 Apr 7;23(1):280. doi: 10.1186/s12864-022-08526-4.
Helictotrichon virescens is a perennial grass that is primarily distributed in high altitude areas of 2000 ~ 4500 m. It is widely cultivated in the Qinghai-Tibet Plateau of China, strongly resistant to cold, and an essential part of the wild herbs in this region. However, the molecular mechanism of the response of H. virescens to low temperature stress and the key regulatory genes for specific biological processes are poorly understood.
Physiological and transcriptome analyses were used to study the cold stress response mechanism in H virescens. During the low temperature stress period, the content of chlorophyll a and b decreased more and more with the delay of the treatment time. Among them, the difference between the controls was not significant, and the difference between the control and the treatment was significant. At the same time, the expression of related differential genes was up-regulated during low temperature treatment. In addition, the plant circadian pathway is crucial for their response to cold stress. The expression of differentially expressed genes that encode LHY and HY5 were strongly up-regulated during cold stress.
This study should help to fully understand how H. virescens responds to low temperatures. It answers pertinent questions in the response of perennial herbs to cold stress, i.e., how light and low temperature signals integrate to regulate plant circadian rhythms and Decrease of content of chlorophylls (which can be also accompanied with decrease of total quantity of reaction centers) leads to an increase in photosynthetic damage.
垂穗披碱草是一种多年生草本植物，主要分布在海拔 2000 ～ 4500m 的高海拔地区。它在中国青藏高原广泛种植，耐寒性强，是该地区野生草药的重要组成部分。然而，垂穗披碱草对低温胁迫的响应分子机制及其特定生物学过程的关键调控基因仍知之甚少。
利用生理和转录组分析研究了垂穗披碱草对低温胁迫的响应机制。在低温胁迫期间，叶绿素 a 和 b 的含量随着处理时间的延迟而越来越低。其中，对照之间差异不显著，对照与处理之间差异显著。同时，低温处理过程中相关差异基因的表达上调。此外，植物生物钟途径对其低温胁迫响应至关重要。低温胁迫下，编码 LHY 和 HY5 的差异表达基因的表达强烈上调。
本研究有助于全面了解垂穗披碱草对低温的响应机制。它回答了多年生草本植物对低温胁迫响应的相关问题，即光和低温信号如何整合来调节植物生物钟，以及叶绿素含量的降低（这也可能伴随着反应中心总量的减少）导致光合作用损伤的增加。
