Physiological Attributes and Transcriptomics Analysis Reveal the Response Mechanism of Helictotrichon Virescens to Low-Temperature Stress

Background: Helictotrichon Virescens is a perennial herb mainly 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 wild herbage in this region. However, the molecular mechanism of Helictotrichon virescens response to low-temperature stress is unclear, and the key regulating genes to specific biological processes are poorly known. Results: It was used physiological and transcriptome analysis to study the cold stress response mechanism in Helictotrichon Virescens . Under low-temperature treatment at 0℃, the leaves reduced chlorophyll content and light energy absorption through light antenna complex (LHCs). As the content of chlorophyll, a and b decreased, as evident were the photoprotection effects. Besides, circadian pathway-plant is crucial for the response to cold stress in Helictotrichon Virescens . Among them, DEG encoding LHY and HY5 showed strongly up-regulated expression during cold stress in Helictotrichon Virescens . Conclusions: This study provides an opportunity to fully understand the response process of Helictotrichon Virescens to low-temperature stress. It answers the pertinent questions in perennial herbaceous cold stress research, how leaves integrate light and low-temperature signals to regulate circadian rhythms in crops, and how leaf tissue reduces light absorption and enhances light protection through optical antenna complex (LHCs).