Overexpression of <italic>ZmCIPKHT</italic> enhances heat tolerance in plant

Abstract

<p id="C3">The effects of high temperature stress on the normal growth and yield of plants is more and more serious. To adapt the changes of external environment, plants have evolved a series of molecular genetic mechanisms to respond to high temperature stress. The calcineurin B-like protein (CBL) interacting protein kinase (CIPK) is actively involved in response to high temperature stress depended on ABA signal transduction pathway in plants. Based on previous genome-wide association analysis, a candidate gene <italic>ZmCIPKHT</italic> related to maize high temperature tolerance was cloned in this study. Real-time quantitative PCR results showed that <italic>ZmCIPKHT</italic> gene was significantly induced by high temperature stress. Transient transformation of maize protoplasts revealed that ZmCIPKHT was localized in the nucleus. Overexpressing <italic>ZmCIPKHT</italic> plants of transgenic <italic>Arabidopsis thaliana</italic> had significantly higher survival rate and better growth status than wild type under high temperature stress. The yeast two-hybrid experiment confirmed that the interaction between ZmCIPKHT protein and ZmCBL4 protein in maize CBLs family. The relative expression levels of genes related to abscisic acid (ABA) pathway in transgenic <italic>Arabidopsis thaliana</italic> with <italic>ZmCIPKHT</italic> under high temperature stress were changed accordingly, indicating that the regulations of <italic>ZmCIPKHT</italic> genes under high temperature stress were in the ABA-dependent pathway. These results provide a new experimental basis for elucidating the molecular mechanism of maize CBL-CIPK signaling pathway dependent on ABA pathway to abiotic stress in plants.