Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao 266237, China.
Agronomy College, Qingdao Agricultural University, Qingdao 266109, China.
Int J Mol Sci. 2024 Jun 6;25(11):6275. doi: 10.3390/ijms25116275.
(maize) is a staple food, feed, and industrial crop. Heat stress is one of the major stresses affecting maize production and is usually accompanied by other stresses, such as drought. Our previous study identified a heterotrimer complex, ZmNF-YA1-YB16-YC17, in maize. ZmNF-YA1 and ZmNF-YB16 were positive regulators of the drought stress response and were involved in maize root development. In this study, we investigated whether ZmNF-YA1 confers heat stress tolerance in maize. The mutant and overexpression lines were used to test the role of ZmNF-YA1 in maize thermotolerance. The mutant was more temperature-sensitive than the wild-type (WT), while the overexpression lines showed a thermotolerant phenotype. Higher malondialdehyde (MDA) content and reactive oxygen species (ROS) accumulation were observed in the mutant, followed by WT and overexpression lines after heat stress treatment, while an opposite trend was observed for chlorophyll content. RNA-seq was used to analyze transcriptome changes in and its wild-type control W22 in response to heat stress. Based on their expression profiles, the heat stress response-related differentially expressed genes (DEGs) in compared to WT were grouped into seven clusters via -means clustering. Gene Ontology (GO) enrichment analysis of the DEGs in different clades was performed to elucidate the roles of ZmNF-YA1-mediated transcriptional regulation and their contribution to maize thermotolerance. The loss function of led to the failure induction of DEGs in GO terms of protein refolding, protein stabilization, and GO terms for various stress responses. Thus, the contribution of ZmNF-YA1 to protein stabilization, refolding, and regulation of abscisic acid (ABA), ROS, and heat/temperature signaling may be the major reason why overexpression enhanced heat tolerance, and the mutant showed a heat-sensitive phenotype.
（玉米）是一种主要的粮食、饲料和工业作物。热胁迫是影响玉米生产的主要胁迫之一，通常伴随着其他胁迫，如干旱。我们之前的研究在玉米中鉴定了一个三聚体复合物ZmNF-YA1-YB16-YC17。ZmNF-YA1 和 ZmNF-YB16 是干旱胁迫反应的正调节剂，参与玉米根系发育。在本研究中，我们研究了 ZmNF-YA1 是否赋予玉米耐热性。使用 突变体和过表达系来测试 ZmNF-YA1 在玉米耐热性中的作用。 突变体比野生型（WT）更对温度敏感，而过表达系表现出耐热表型。在热胁迫处理后，突变体中观察到更高的丙二醛（MDA）含量和活性氧（ROS）积累，随后是 WT 和过表达系，而叶绿素含量则呈现相反的趋势。使用 RNA-seq 分析 及其野生型对照 W22 对热胁迫的转录组变化。根据它们的表达谱，通过 -means 聚类将 中与热应激相关的差异表达基因（DEGs）根据其表达谱分为七个簇。对不同聚类中 DEGs 的基因本体论（GO）富集分析表明，ZmNF-YA1 介导的转录调控及其对玉米耐热性的贡献。 的功能丧失导致 DEGs 在蛋白质重折叠、蛋白质稳定和各种应激反应的 GO 术语中不能被诱导。因此，ZmNF-YA1 对蛋白质稳定、折叠和脱落酸（ABA）、ROS 和热/温度信号转导的调节的贡献可能是 过表达增强耐热性和突变体表现出耐热性的主要原因。
