State Key Laboratory of Cotton Biology / Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, China; College of Agronomy, Xinjiang Agricultural University, Ürümqi, China.
College of Agronomy, Xinjiang Agricultural University, Ürümqi, China.
Gene. 2023 Jul 20;874:147486. doi: 10.1016/j.gene.2023.147486. Epub 2023 May 16.
Heat stress significantly affect plant growth and development, which is an important factor contributing to crop yield loss. However, heat shock proteins (HSPs) in plants can effectively alleviate cell damage caused by heat stress. In order to rapidly and accurately cultivate heat-tolerant cotton varieties, this study conducted correlation analysis between heat tolerance index and insertion/deletion (In/Del) sites of GhHSP70-26 promoter in 39 cotton materials, so as to find markers related to heat tolerance function of cotton, which can be used in molecular marker-assisted breeding. The results showed the natural variation allele (Del22 bp) type at -1590 bp upstream of GhHSP70-26 promoter (haplotype2, Hap2) in cotton (Gossypium spp.) promoted GhHSP70-26 expression under heat stress. The relative expression level of GhHSP70-26 of M-1590-Del22 cotton materials were significantly higher than that of M-1590-In type cotton materials under heat stress (40 ℃). Also, M-1590-Del22 material had lower conductivity and less cell damage after heat stress, indicating that it is a heat resistant cotton material. The Hap1 (M-1590-In) promoter was mutated into Hap1, and Hap1 and Hap1 were fused with GUS to transform Arabidopsis thaliana. Furthermore, Hap1 promoter had higher induction activity than Hap1 under heat stress and abscisic acid (ABA) treatment in transgenic Arabidopsis thaliana. Further analysis confirmed that M-1590-Del22 was the dominant heat-resistant allele. In summary, these results identify a key and previously unknown natural variation in GhHSP70-26 with respect to heat tolerance, providing a valuable functional molecular marker for genetic breeding of cotton and other crops with heat tolerance.
热应激显著影响植物的生长和发育，是导致作物减产的重要因素。然而，植物中的热休克蛋白（HSPs）可以有效缓解热应激引起的细胞损伤。为了快速准确地培育耐热棉花品种，本研究对 39 份棉花材料的 GhHSP70-26 启动子的耐热指数与插入/缺失（In/Del）位点进行了相关性分析，以期找到与棉花耐热功能相关的标记，可用于分子标记辅助育种。结果表明，GhHSP70-26 启动子-1590bp 上游的自然变异等位基因（Del22bp）类型（Hap2）在棉花（Gossypium spp.）中促进了 GhHSP70-26 在热应激下的表达。在热应激（40℃）下，M-1590-Del22 棉花材料的 GhHSP70-26 相对表达水平明显高于 M-1590-In 型棉花材料。此外，M-1590-Del22 材料在热应激后电导率较低，细胞损伤较少，表明其为耐热棉花材料。将 Hap1（M-1590-In）启动子突变为 Hap1，并将 Hap1 和 Hap1 与 GUS 融合转化拟南芥。进一步研究表明，在热应激和脱落酸（ABA）处理下，Hap1 启动子在转基因拟南芥中比 Hap1 具有更高的诱导活性。进一步分析证实，M-1590-Del22 是耐热的优势等位基因。综上所述，这些结果确定了 GhHSP70-26 与耐热性相关的一个关键且先前未知的自然变异，为棉花及其他作物的耐热遗传育种提供了有价值的功能分子标记。
