National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
BMC Plant Biol. 2022 Aug 20;22(1):406. doi: 10.1186/s12870-022-03789-1.
Heat shock transcription factors (Hsfs) are highly conserved among eukaryote and always play vital role in plant stress responses. Whereas, function and mechanism of Hsfs in maize are limited.
In this study, an HSF gene ZmHsf11, a member of class B Hsfs, was cloned from maize, and it was up-regulated under heat treatment. ZmHsf11 was a nuclear protein with no transcriptional autoactivation activity in yeast. Overexpression of ZmHsf11 gene in Arabidopsis and rice significantly reduced the survival rate under heat shock treatment and decreased ABA sensitivity of transgenic plants. Under heat stress, transgenic rice accumulated more HO, increased cell death, and decreased proline content compared with wild type. In addition, RT-qPCR analysis revealed that ZmHsf11 negatively regulated some oxidative stress-related genes APX2, DREB2A, HsfA2e, NTL3, GR and HSP17 under heat stress treatment.
Our results indicate that ZmHsf11 decreases plant tolerance to heat stress by negatively regulating the expression of oxidative stress-related genes, increasing ROS levels and decreasing proline content. It is a negative regulator involved in high temperature stress response.
热休克转录因子（Hsfs）在真核生物中高度保守，在植物应激反应中始终发挥重要作用。然而，玉米中 Hsfs 的功能和机制尚不清楚。
本研究从玉米中克隆了一个属于 B 类 Hsfs 的 HSF 基因 ZmHsf11，该基因在热处理下上调表达。ZmHsf11 是一种核蛋白，在酵母中没有转录自动激活活性。ZmHsf11 基因在拟南芥和水稻中的过表达显著降低了热休克处理下的存活率，并降低了转基因植物对 ABA 的敏感性。在热胁迫下，与野生型相比，转基因水稻积累了更多的 HO，细胞死亡增加，脯氨酸含量降低。此外，RT-qPCR 分析表明，ZmHsf11 负调控一些与氧化应激相关的基因 APX2、DREB2A、HsfA2e、NTL3、GR 和 HSP17 在热胁迫处理下的表达。
我们的结果表明，ZmHsf11 通过负调控与氧化应激相关的基因表达、增加 ROS 水平和降低脯氨酸含量，降低植物对热胁迫的耐受性。它是参与高温胁迫反应的负调控因子。
