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MAPK‐like protein 1 positively regulates maize seedling drought sensitivity by suppressing ABA biosynthesis
Author(s) -
Zhu Dan,
Chang Ying,
Pei Ting,
Zhang Xiuyan,
Liu Lan,
Li Yuan,
Zhuang Junhong,
Yang Hailian,
Qin Feng,
Song Chunpeng,
Ren Dongtao
Publication year - 2020
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14660
Subject(s) - abscisic acid , kinase , seedling , biology , catabolism , gene , mapk/erk pathway , drought tolerance , microbiology and biotechnology , arabidopsis , protein kinase a , transcription factor , mutant , botany , biochemistry , enzyme
Summary 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 named ZmMPKL1 to ZmMPKL4 . In this study, we show that ZmMPKL1 possesses kinase activity and that drought‐induced ZmMPKL1 expression, ZmMPKL1 overexpression 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 in ZmMPKL1‐ overexpressing seedlings were restored by exogenous abscisic acid (ABA). ZmMPKL1 overexpression 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 in ZmMPKL1‐ 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.