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.

寒凉与干旱胁迫为高山地区最为严峻的两种非生物胁迫。冰草（Poa crymophila）在青藏高原广泛种植，表现出强大的耐受力。本研究通过分析基因表达模式和与代谢组学相关的转录组共表达网络，揭示了冰草对这两种胁迫的适应机制。（1）冷旱胁迫下，耐受胁迫的基因和代谢物被诱导表达，而与生长相关的基因则受到抑制，且在胁迫解除后，大部分基因和代谢物得以快速恢复。特别是光合作用系统的基因展现出强大的恢复力。（2）此外，冷旱胁迫激活了缺氧和UV-B适应性基因，这表明长期生活在高原环境可能产生特殊的适应性。（3）苯乙胺、多胺和氨基酸，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。对于冰草而言，灵活的响应和快速的恢复是其适应干旱和寒冷的策略，这也是其强韧耐受力和恢复力的原因。在本研究中，我们呈现了冰草的全面胁迫响应图谱，并提供了许多候选基因或代谢物，为未来的牧草改良提供了依据。