Maize WRKY Transcription Factor ZmWRKY79 Positively Regulates Drought Tolerance through Elevating ABA Biosynthesis

International Journal of Molecular Sciences

卷:22

Beenish Hassan¹  Jingye Fu²  Jie Yan²  Chenying Zhu²  Tehseen Ahmad Meraj²  Faiza Gulzar²  Qinqin Shen²  Xinglin Li²  Qiang Wang² 

[1] Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;

[2] State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Chengdu 611130, China;

关键词: drought;    maize;    ABA;    transcription factor;    WRKY;   

DOI  :  10.3390/ijms221810080

来源: DOAJ

【 摘 要 】

Drought stress causes heavy damages to crop growth and productivity under global climatic changes. Transcription factors have been extensively studied in many crops to play important roles in plant growth and defense. However, there is a scarcity of studies regarding WRKY transcription factors regulating drought responses in maize crops. Previously, ZmWRKY79 was identified as the regulator of maize phytoalexin biosynthesis with inducible expression under different elicitation. Here, we elucidated the function of ZmWRKY79 in drought stress through regulating ABA biosynthesis. The overexpression of ZmWRKY79 in Arabidopsis improved the survival rate under drought stress, which was accompanied by more lateral roots, lower stomatal aperture, and water loss. ROS scavenging was also boosted by ZmWRKY79 to result in less H₂O₂ and MDA accumulation and increased antioxidant enzyme activities. Further analysis detected more ABA production in ZmWRKY79 overexpression lines under drought stress, which was consistent with up-regulated ABA biosynthetic gene expression by RNA-seq analysis. ZmWRKY79 was observed to target ZmAAO3 genes in maize protoplast through acting on the specific W-boxes of the corresponding gene promoters. Virus-induced gene silencing of ZmWRKY79 in maize resulted in compromised drought tolerance with more H₂O₂ accumulation and weaker root system architecture. Together, this study substantiates the role of ZmWRKY79 in the drought-tolerance mechanism through regulating ABA biosynthesis, suggesting its broad functions not only as the regulator in phytoalexin biosynthesis against pathogen infection but also playing the positive role in abiotic stress response, which provides a WRKY candidate gene to improve drought tolerance for maize and other crop plants.

【 授权许可】

Unknown