Table_4_Flexible response and rapid recovery strategies of the plateau forage Poa crymophila to cold and drought.xlsx

Cold and drought stress are the two most severe abiotic stresses in alpine regions. Poa crymophila is widely grown in the Qinghai–Tibet Plateau with strong tolerance. Here, by profiling gene expression patterns and metabolomics-associated transcriptomics co-expression network, the acclimation of Poa crymophila to the two stresses was characterized. (1) The genes and metabolites with stress tolerance were induced by cold and drought, while those related with growth were inhibited, and most of them were restored faster after stresses disappeared. In particular, the genes for the photosynthesis system had strong resilience. (2) Additionally, cold and drought activated hypoxia and UV-B adaptation genes, indicating long-term life on the plateau could produce special adaptations. (3) Phenolamines, polyamines, and amino acids, especially N′,N″,N′″-p-coumaroyl-cinnamoyl-caffeoyl spermidine, putrescine, and arginine, play key roles in harsh environments. Flexible response and quick recovery are strategies for adaptation to drought and cold in P. crymophila, accounting for its robust tolerance and resilience. In this study, we presented a comprehensive stress response profile of P. crymophila and provided many candidate genes or metabolites for future forage improvement.

高山地区中，寒冷与干旱胁迫被视为两种最为严重的非生物胁迫。青海-西藏高原广泛种植的羊草（Poa crymophila）表现出较强的耐受力。本研究通过对基因表达模式和代谢组学相关转录组共表达网络进行剖析，揭示了羊草对这两种胁迫的适应性特征。（1）耐胁迫的基因与代谢物在寒冷与干旱条件下被诱导表达，而与生长相关的基因则受到抑制，大部分基因在胁迫消失后恢复速度较快。特别是光合作用系统的基因展现出强大的恢复力。（2）此外，寒冷与干旱激活了缺氧和UV-B适应性基因，表明长期生活在高原上能够产生特殊的适应性。（3）苯丙胺类、多胺类和氨基酸，尤其是N′，N″，N′″-对香豆酰基肉桂酰基咖啡酰基精胺、腐胺和精氨酸，在恶劣环境中扮演着关键角色。羊草对干旱和寒冷的灵活响应与快速恢复策略，是其强韧耐受力和恢复力的原因。在本研究中，我们展示了羊草的全面胁迫响应图谱，并为未来的牧草改良提供了众多候选基因或代谢物。