State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, China.
Hebei Base of State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Hebei Agricultural University, Baoding, Hebei, China.
Physiol Plant. 2024 May-Jun;176(3):e14331. doi: 10.1111/ppl.14331.
Sporopollenin, as the main component of the pollen exine, is a highly resistant polymer that provides structural integrity under unfavourable environmental conditions. Tetraketone α-pyrone reductase 1 (TKPR1) is essential for sporopollenin formation, catalyzing the reduction of tetraketone carbonyl to hydroxylated α-pyrone. The functional role of TKPR1 in male sterility has been reported in flowering plants such as maize, rice, and Arabidopsis. However, the molecular cloning and functional characterization of TKPR1 in cotton remain unaddressed. In this study, we identified 68 TKPR1s from four cotton species, categorized into three clades. Transcriptomics and RT-qPCR demonstrated that GhTKPR1_8 exhibited typical expression patterns in the tetrad stage of the anther. GhTKPR1_8 was localized to the endoplasmic reticulum. Moreover, ABORTED MICROSPORES (GhAMS) transcriptionally activated GhTKPR1_8 as indicated by luciferase complementation tests. GhTKPR1_8-knockdown inhibited anther dehiscence and reduced pollen viability in cotton. Additionally, overexpression of GhTKPR1_8 in the attkpr1 mutant restored its male sterile phenotype. This study offers novel insights into the investigation of TKPR1 in cotton while providing genetic resources for studying male sterility.
花粉外壁的主要成分是孢粉素，它是一种高度抗性的聚合物，在不利的环境条件下提供结构完整性。四酮α-吡喃酮还原酶 1（TKPR1）对于孢粉素的形成是必不可少的，它催化四酮羰基还原为羟基化的α-吡喃酮。TKPR1 在玉米、水稻和拟南芥等开花植物中的雄性不育中的功能作用已有报道。然而，棉花中 TKPR1 的分子克隆和功能表征尚未得到解决。在这项研究中，我们从四个棉花物种中鉴定出 68 个 TKPR1，分为三个分支。转录组学和 RT-qPCR 表明 GhTKPR1_8 在花药四分体阶段表现出典型的表达模式。GhTKPR1_8 定位于内质网。此外，通过荧光素酶互补试验表明，ABORTED MICROSPORES（GhAMS）转录激活了 GhTKPR1_8。GhTKPR1_8 的敲低抑制了棉花花药开裂，并降低了花粉活力。此外，在 attkpr1 突变体中过表达 GhTKPR1_8 恢复了其雄性不育表型。本研究为研究棉花中的 TKPR1 提供了新的见解，并为研究雄性不育提供了遗传资源。
