Maize WRKY114 gene negatively regulates salt-stress tolerance in transgenic rice

• DOI: 10.1007/s00299-019-02481-3
• Publication Date: 2019-10-28T15:05:48Z
• Authors: Chen Bo; Haowei Chen; Guowei Luo; Wei Li; Xingen Zhang; Qing Ma; Beijiu Cheng; Ronghao Cai
• Keywords: Cell Nucleus; 0301 basic medicine; 2. Zero hunger; Oryza; Salt Tolerance; Plants, Genetically Modified; Salt Stress; Zea mays; 03 medical and health sciences; Gene Expression Regulation, Plant; Seedlings; Abscisic Acid; Plant Proteins; Transcription Factors

Overexpression in rice of the isolated salt-responsive WRKY114 gene from maize resulted in decreases in both salt-stress tolerance and abscisic acid sensitivity by regulating stress- and abscisic acid-related gene expression. WRKYs are an important family of transcription factors that widely participate in plant development, defense regulation and stress responses. In this research, WRKY114 encoding a WRKY transcription factor was cloned from maize (Zea mays L.). ZmWRKY114 expression was down-regulated by salt stress but up-regulated by abscisic acid (ABA) treatments. ZmWRKY114 is a nuclear protein with no transcriptional activation ability in yeast. A yeast one-hybrid experiment confirmed that ZmWRKY114 possesses an ability to specifically bind to W-boxes. The heterologous overexpression of ZmWRKY114 in rice enhanced the salt-stress sensitivity as indicated by the transgenic plants having reduced heights, root lengths and survival rates under salt-stress conditions. In addition, transgenic plants also retained lower proline contents, but greater malondialdehyde contents and relative electrical leakage levels. Additionally, ZmWRKY114-overexpressing plants showed less sensitivity to ABA during the early seedling growth stage. Further analyses indicated that transgenic rice accumulated higher levels of ABA than wild-type plants under salt-stress conditions. Transcriptome and quantitative real-time PCR analyses indicated that a few regulatory genes, which play vital roles in controlling plant stress responses and/or the ABA signaling pathway, were affected by ZmWRKY114 overexpression when rice was treated with NaCl. Thus, ZmWRKY114 may function as a negative factor that participates in salt-stress responses through an ABA-mediated pathway.