Abstract：
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.
摘要：
孢子蛋白,作为花粉外壁的主要成分，是一种高抗性聚合物，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）是孢子囊蛋白形成所必需的，催化四酮羰基还原为羟基化α-吡喃酮。TKPR1在雄性不育中的功能作用已在开花植物如玉米中报道，大米,和拟南芥。然而,棉花中TKPR1的分子克隆和功能表征仍未解决。在这项研究中,我们从四种棉种中鉴定出68种TKPR1，分为三个分支。转录组学和RT-qPCR表明GhTKPR1_8在花药的四聚体阶段表现出典型的表达模式。GhTKPR1_8定位于内质网。此外，如荧光素酶互补试验所示,缺失的微孢子(GhAMS)转录激活的GhTKPR1_8。GhTKPR1_8敲除抑制棉花花药开裂，降低花粉活力。此外,在attkpr1突变体中过表达GhTKPR1_8恢复了其雄性不育表型。这项研究为棉花中TKPR1的研究提供了新的见解，同时为研究雄性不育提供了遗传资源。
