Abstract The present study aims at the use of transcriptomic data of wild barley (Hordeum spontaneum) under salt stress in detecting regulated metabolites and crosstalking signal transduction pathways that help plants withstand harsh conditions. The studied pathways involved those emphasizing the roles of phytohormones auxin and abscisic acid (ABA) in conferring stress tolerance and adaptation. Of which, tryptophan-core pathways include metabolites that trigger auxin-responsive genes towards downstream signal transduction cascades and better plant growth. Analysis of ‘MAPK signalling’ pathway indicated active participation of several MAPK modules in receiving and delivering signals under salt stress towards appropriate downstream biological decisions. The results indicated that one enriched MEKK1 module, e.g. MEKK1-MKK2-MPK4/6, and two MKK3 modules, e.g. MEKK17/18-MKK3-MPK1/2/7/14 and ?-MKK3-MPK8, in this wild plant can effectively participate in salt stress adaptation and tolerance as well as homeostasis of reactive oxygen species (ROS). ABA seems to be a main player in the leaves of H. spontaneum in triggering signal transduction via MAPK modules. MKK7 was shown to be repressed under salt stress. This MAPK disturbs normal production, signalling and distribution of auxin, thus, enforces the plant to perform better under salt stress. In conclusion, the present study addresses signal transduction pathways that might justify the ability of this wild plant to tolerate salt stress.

中文翻译：

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盐胁迫下野生大麦（Hordeum spontaneum）叶片的逐步信号转导级联

摘要 本研究旨在利用盐胁迫下野生大麦 (Hordeum spontaneum) 的转录组数据来检测可帮助植物抵御恶劣条件的调节代谢物和串扰信号转导途径。研究的途径涉及那些强调植物激素生长素和脱落酸 (ABA) 在赋予胁迫耐受性和适应能力方面的作用的途径。其中，色氨酸核心途径包括触发生长素响应基因向下游信号转导级联和更好的植物生长的代谢物。对“MAPK 信号传导”途径的分析表明，几个 MAPK 模块积极参与在盐胁迫下接收和传递信号，以实现适当的下游生物决策。结果表明，一个富含 MEKK1 的模块，例如 MEKK1-MKK2-MPK4/6，和两个 MKK3 模块，例如 MEKK17/18-MKK3-MPK1/2/7/14 和 ?-MKK3-MPK8，在该野生植物中可以有效参与盐胁迫适应和耐受以及活性氧 (ROS) 的稳态. ABA 似乎是 H. spontaneum 叶子中通过 MAPK 模块触发信号转导的主要参与者。MKK7 在盐胁迫下被抑制。该 MAPK 会干扰生长素的正常生产、信号传导和分布，因此，迫使植物在盐胁迫下表现更好。总之，本研究解决了可能证明这种野生植物耐受盐胁迫的能力的信号转导途径。ABA 似乎是 H. spontaneum 叶子中通过 MAPK 模块触发信号转导的主要参与者。MKK7 在盐胁迫下被抑制。该 MAPK 会干扰生长素的正常生产、信号传导和分布，因此，迫使植物在盐胁迫下表现更好。总之，本研究解决了可能证明这种野生植物耐受盐胁迫的能力的信号转导途径。ABA 似乎是 H. spontaneum 叶子中通过 MAPK 模块触发信号转导的主要参与者。MKK7 在盐胁迫下被抑制。该 MAPK 会干扰生长素的正常生产、信号传导和分布，因此，迫使植物在盐胁迫下表现更好。总之，本研究解决了可能证明这种野生植物耐受盐胁迫的能力的信号转导途径。