WRKY transcription factors play key roles in plant biotic and abiotic stress responses, but the function of some MaWRKYs remains elusive. Here, we characterized the positive role of MaWRKY80 in drought stress resistance and the underlying mechanism. MaWRKY80 was significantly upregulated under drought stress and confirmed as a transcription factor that could bind to the W-box. Overexpression of MaWRKY80 in Arabidopsis showed better phenotypic morphology, higher survival rate, less water loss rate, and lower malondialdehyde level than wild type (WT) under drought stress. Consistently, MaWRKY80 transgenic Arabidopsis leaves displayed significantly lower reactive oxygen species (ROS) than WT under drought stress. Moreover, MaWRKY80 mediated the stomata movement and leaf water retention capacity through modulation of the transcript of 9-cis-epoxycarotenoid dioxygenases (NCEDs) and abscisic acid (ABA) biosynthesis in Arabidopsis. Notably, chromatin immunoprecipitation quantitative real-time PCR (ChIP-PCR) and electrophoretic mobility shift assay (EMSA) provided evidences supporting the direct and specific interaction between MaWRKY80 and both the W-box in AtNCEDs promoter in Arabidopsis and the W-box in MaNCEDs promoter in banana. Taken together, MaWRKY80 serves as a positive regulator of drought stress resistance through modulating ABA level by regulating NCEDs expression and ROS accumulation by regulating antioxidant system. This study provides a novel insight into MaWRKY80 in coordinating ABA synthesis and ROS elimination in response to drought stress.

WRKY转录因子在植物生物和非生物胁迫响应中起着关键作用，但是某些MaWRKY的功能仍然难以捉摸。在这里，我们表征了MaWRKY80在抗旱胁迫中的积极作用及其潜在机制。MaWRKY80在干旱胁迫下显着上调，并被确认为可与W-box结合的转录因子。在干旱胁迫下，拟南芥中MaWRKY80的过表达表现出比野生型更好的表型形态，更高的存活率，更少的失水率和更低的丙二醛水平。一致地，MaWRKY80转基因拟南芥在干旱胁迫下，叶片的活性氧（ROS）显着低于野生型。此外，MaWRKY80通过调节拟南芥9-顺式-环氧类胡萝卜素双加氧酶（NCEDs）和脱落酸（ABA）生物合成的转录本，介导气孔运动和叶片保水能力。值得注意的是，染色质免疫沉淀定量实时PCR（芯片PCR）和电泳迁移率变动分析（EMSA）提供证据支持直接与特定的相互作用MaWRKY80和两个W-盒在AtNCEDs启动子在拟南芥和在W-盒MaNCEDs香蕉中的启动子。两者合计，MaWRKY80通过调节NCEDs的表达来调节ABA的水平和通过调节抗氧化剂的系统来促进ROS的积累，从而成为抗干旱胁迫的积极调节剂。这项研究提供了对MaWRKY80的新见解，以协调干旱胁迫下的ABA合成和ROS消除。