Key message

This study revealed the ABA-dependent signaling pathway and flavonoid synthesis pathway of sea buckthorn under drought conditions from plant physiology and gene expression levels.

Abstract

As climate changes and temperatures rise, sea buckthorn (Hippophae rhamnoides L.) is increasingly exposed to numerous challenges, particularly aridity. In this study, the leaves of sea buckthorn were harvested from plants in drought-recovery cycles and selected for RNA sequencing to uncover the underlying genetic basis of drought stress response through physiological and biochemical analyses. The results revealed that drought conditions significantly (p < 0.05) decreased leaf water potential, net photosynthetic rate, and stomatal conductance, Abscisic acid (ABA) and flavone content significantly (p < 0.05) increased under drought conditions and recovered after rehydration. Compared with the control and recovery irrigation conditions, respectively, 7734 and 7338 genes were differentially expressed under drought stress. Major differentially expressed genes involved in ABA-dependent signaling and flavonoid biosynthesis pathways were identified. Six hub genes of the co-expression network were blasted against the Drought Stress Gene Database and were found to have direct relationships with 25 genes there were related to cellular responses to stimuli. Five hub genes and seven drought transcription factors were validated by RT-qPCR. This study elucidated the molecular mechanism of the ABA-dependent signaling pathway that affects stomatal closure and flavonoid biosynthesis in antioxidant systems under drought conditions in sea buckthorn. The identified six hub genes will serve as a valuable resource and provide essential information for improving sea buckthorn tolerance to drought conditions.

中文翻译：

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沙棘对干旱胁迫响应的转录本和ABA依赖性信号传导

关键信息

这项研究从植物生理和基因表达水平揭示了干旱条件下沙棘的ABA依赖性信号传导途径和类黄酮合成途径。

抽象

随着气候变化和温度升高，沙棘（Hippophae rhamnoides L.）越来越面临众多挑战，特别是干旱。在这项研究中，沙棘的叶子是在干旱恢复周期中从植物中收获的，并选择进行RNA测序以通过生理和生化分析揭示干旱胁迫反应的潜在遗传基础。结果表明，干旱条件显着（p  <0.05）降低了叶片水势，净光合速率和气孔导度，脱落酸（ABA）和黄酮含量显着（p <0.05）在干旱条件下增加并在补水后恢复。与控制和恢复灌溉条件相比，干旱胁迫下差异表达了7734和7338基因。确定了参与ABA依赖性信号传导和类黄酮生物合成途径的主要差异表达基因。共表达网络的六个中枢基因被针对干旱胁迫基因数据库进行了爆炸，发现与25个基因有直接关系，这些基因与细胞对刺激的反应有关。RT-qPCR验证了5个毂基因和7个干旱转录因子。这项研究阐明了沙棘中干旱条件下影响抗氧化剂系统中气孔关闭和类黄酮生物合成的依赖ABA的信号通路的分子机制。