论文题目：Two alternatively spliced variants of ZmHSF12 regulate the balance of plant growth and heat tolerance in maize and Arabidopsis
论文作者：Junlong Qi, Chunxia Zhang, Longhui Yang, Ying Liu, Guoji Wang, Shixiao Li, Lynnette M. Dirk, A. Bruce Downie and Tianyong Zhao
论文摘要：Heat shock factors (HSFs) are pivotal in regulating plant heat tolerance; however, the mechanisms HSFs employ in regulating transcription to maintain a balance of plant growth and heat tolerance are poorly understood. This study reports that two maize HSF12 knockout lines are more sensitive to heat stress. ZmHSF12 encodes two alternative spliced transcripts: ZmHSF12-1 and ZmHSF12-2; overexpression of ZmHSF12-2 enhances, whereas overexpression of ZmHSF12-1 decreases plant heat tolerance, indicating the distinct functions of these two transcripts in plant heat stress response. In addition, ZmHSF12-2 upregulates RAFFINOSE SYNTHASE (ZmRAFS) and CYTOKININ OXIDASE (ZmCKO2) gene expression, controlling raffinose and cytokinin concentration in the cell, enhancing plant heat tolerance and inhibiting plant growth. ZmHSF12-1 interacts with ZmHSF12-2 and represses the transcriptional regulation of ZmHSF12-2 on ZmCKO2 and ZmRAFS. Co-overexpression of ZmHSF12-1 and ZmHSF12-2 in Arabidopsis not only improved the heat tolerance of plants but also compensated for the growth defect phenotype of ZmHSF12-2 overexpressing Arabidopsis plants. These findings deepen our understanding of plant heat tolerance and significantly impact the scientific community. They support the potential application of co-overexpressing ZmHSF12-1 and ZmHSF12-2 to improve crop heat tolerance without causing growth retardation and yield.
西北农林科技大学赵天永课题组前期研究发现玉米ZmHSF2A与ZmHSBP2通过拮抗调控棉子糖合成途径影响植物耐热性（Gu L et al., The Plant Journal, 2019）。最新研究中，该团队聚焦高温诱导表达最显著的玉米HSF成员——ZmHSF12。该基因通过可变剪接产生ZmHSF12-1和ZmHSF12-2两种转录本。近期发表于The Plant Journal的研究论文"Two alternatively spliced variants of ZmHSF12 regulate the balance of plant growth and heat tolerance in maize and Arabidopsis"揭示：ZmHSF12-2通过协同激活棉子糖合成与肌醇转运途径增强植物耐热性，同时通过抑制细胞分裂素合成与信号转导延缓植物生长；而ZmHSF12-1则通过拮抗ZmHSF12-2的转录激活功能解除生长抑制，从而维持生长与耐热的动态平衡。该发现创新性提出共表达两种剪接变体的育种策略，可在不牺牲作物生长速率和产量的前提下提升耐热性。
原文链接：http://dx.doi.org/10.1111/tpj.70372