MAPK-like protein 1 positively regulates maize seedling drought sensitivity by suppressing ABA biosynthesis
MAPK-like protein 1 positively regulates maize seedling drought sensitivity by suppressing ABA biosynthesis
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MAPK样蛋白1通过抑制ABA生物合成正向调节玉米幼苗的干旱敏感性
DOI：
10.1111/tpj.14660
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Ren Dongtao
中科院分区：
文献类型：
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作者：
Zhu Dan;Chang Ying;Pei Ting;Zhang Xiuyan;Liu Lan;Li Yuan;Zhuang Junhong;Yang Hailian;Qin Feng;Song Chunpeng;Ren Dongtao
丝裂原活化蛋白激酶（MAPK）级联在调节植物生长、发育和胁迫反应中起着至关重要的作用。MAPK样（MPKL）蛋白是一类含有MAPK信号TxY基序并与MAPK序列相似的激酶。然而，植物MPKL蛋白的功能目前尚不清楚。玉米（Zea mays）基因组包含编码MPKL蛋白的四个基因，在此命名为ZmMPKL 1至ZmMPKL 4。在这项研究中，我们表明ZmMPKL 1具有激酶活性，并且在正常条件下生长时，干旱诱导的ZmMPKL 1表达，ZmMPKL 1过表达和敲除玉米幼苗与野生型B73幼苗没有明显的形态差异。相比之下，在干旱条件下，ZmMPKL 1过表达的幼苗表现出气孔开度增加，水分流失，叶片萎蔫，敲除幼苗表现出相反的表型。此外，ZmMPKL 1过表达的幼苗中的这些干旱敏感表型被外源脱落酸（阿坝）恢复。ZmMPKL 1过表达降低了幼苗中干旱诱导的阿坝产生，而ZmMPKL 1敲除则显示出阿坝产生的增强。在ZmMPKL 1过表达的幼苗中，干旱诱导的阿坝生物合成基因的转录受到抑制，阿坝分解代谢基因的转录得到增强，而在ZmMPKL 1基因敲除的幼苗中，这些基因的转录受到抑制。这些结果表明，ZmMPKL 1通过改变阿坝生物合成和分解代谢基因的转录以及阿坝动态平衡来正向调节幼苗的干旱敏感性。
Mitogen‐activated protein kinase (MAPK) cascades play vital roles in regulating plant growth, development, and stress responses. MAPK‐like (MPKL) proteins are a group of kinases containing the MAPK signature TxY motif and showing sequence similarity to MAPKs. However, the functions of plant MPKL proteins are currently unknown. The maize (Zea mays) genome contains four genes encoding MPKL proteins, here namedZmMPKL1toZmMPKL4. In this study, we show that ZmMPKL1 possesses kinase activity and that drought‐inducedZmMPKL1expression,ZmMPKL1overexpression and knockout maize seedlings exhibited no visible morphological difference from wild‐type B73 seedlings when grown under normal conditions. By contrast, under drought conditions,ZmMPKL1‐overexpressing seedlings showed increased stomatal aperture, water loss, and leaf wilting and knockout seedlings showed the opposite phenotypes. Moreover, these drought‐sensitive phenotypes inZmMPKL1‐overexpressing seedlings were restored by exogenous abscisic acid (ABA).ZmMPKL1overexpression reduced drought‐induced ABA production in seedlings and the knockout showed enhanced ABA production. Drought‐induced transcription of ABA biosynthetic genes were suppressed and ABA catabolic genes were enhanced inZmMPKL1‐overexpressing seedlings, while their transcription were reversely regulated in knockout seedlings. These results suggest that ZmMPKL1 positively regulates seedlings drought sensitivity by altering the transcription of ABA biosynthetic and catabolic genes, and ABA homeostasis.