The mitogen-activated protein kinase (MAPK) cascade pathway, which has three components, MAP3Ks, MKKs and MPKs, is involved in diverse biological processes in plants. In the current study, MAPK cascade genes were identified in three cotton species, based on gene homology with Arabidopsis. Selection pressure analysis of MAPK cascade genes revealed that purifying selection occurred among the cotton species. Expression pattern analysis showed that some MAPK cascade genes differentially expressed under abiotic stresses and phytohormones treatments, and especially under drought stress. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) experiments showed extensive interactions between different MAPK cascade proteins. Virus-induced gene silencing (VIGS) assays showed that some MAPK cascade modules play important roles in the drought stress response, and the GhMAP3K14-GhMKK11-GhMPK31 signal pathway was demonstrated to regulate drought stress tolerance in cotton. This study provides new information on the function of MAPK cascade genes in the drought response, and will help direct molecular breeding for improved drought stress tolerance in cotton.

中文翻译：

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MAPK级联基因的全基因组鉴定揭示了GhMAP3K14-GhMKK11-GhMPK31途径与棉花的干旱反应有关。

有丝分裂原激活的蛋白激酶（MAPK）级联途径具有MAP3K，MKK和MPK三个成分，参与植物的多种生物过程。在当前的研究中，基于与拟南芥的基因同源性，在三种棉花中鉴定了MAPK级联基因。MAPK级联基因的选择压力分析表明，纯化选择发生在棉花品种之间。表达模式分析表明，在非生物胁迫和植物激素处理下，特别是在干旱胁迫下，一些MAPK级联基因差异表达。酵母双杂交（Y2H）和双分子荧光互补（BiFC）实验表明，不同的MAPK级联蛋白之间存在广泛的相互作用。病毒诱导的基因沉默（VIGS）分析表明，一些MAPK级联模块在干旱胁迫响应中起重要作用，并且GhMAP3K14-GhMKK11-GhMPK31信号通路被证明调节棉花的干旱胁迫耐受性。这项研究提供了有关MAPK级联基因在干旱响应中的功能的新信息，并将有助于指导分子育种提高棉花的干旱胁迫耐受性。