Cotton pollen abortion, under drought stress, was closely associated with changes in anther carbohydrate metabolism, and pollen abortion rate due to drought was higher in drought-sensitive cultivars than drought-tolerant cultivars. Cotton reproductive failure under drought stress is intrinsically connected with altered male fertility, however, studies investigating the effect of drought stress on cotton male fertility are nonexistent. Thus, a drought stress experiment was conducted with two cotton cultivars, differing in drought tolerance, to study pollen fertility and anthers' physiology. Results indicated that drought stress reduced pollen fertility of both cultivars due to decreases in anther starch and adenosine triphosphate (ATP) synthesis. Lower assimilate supply capacity in conjunction with impaired activities of ADP-glucose pyrophosphorylase and soluble starch synthase were the main reasons for the decreased starch levels in drought-stressed anthers. The decreased activities of sucrose synthetase and acid invertase were responsible for the higher sucrose level in drought-stressed anthers than well-watered anthers and the changing trend of sucrose was intensified by the decreased expressions of sucrose synthase genes (GhSusA, GhSusB, GhSusD) and acid invertase genes (GhINV1, GhINV2). However, despite sucrose degradation being limited in drought-stressed anthers, glucose level was higher in droughted anthers than well-watered ones, and that might be attributed to the down-regulated respiration since decreased anther ATP levels were detected in drought-stressed plants. Furthermore, compared to the drought-tolerant cultivar, pollen fertility was more suppressed by drought stress for the drought-sensitive cultivar, and that was attributed to the larger decrease in starch and ATP contents.

中文翻译：

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干旱诱导的两种不同耐旱性陆地棉品种的花药碳水化合物代谢紊乱和雄性流产。

干旱胁迫下的棉花花粉败育与花药碳水化合物代谢的变化密切相关，干旱敏感品种的花粉败育率高于耐旱品种。干旱胁迫下的棉花繁殖失败与雄性生育力的改变存在内在联系，然而，研究干旱胁迫对棉花雄性生育力的影响的研究尚不存在。因此，对耐旱性不同的两个棉花品种进行了干旱胁迫试验，以研究花粉育性和花药生理。结果表明，由于花药淀粉和三磷酸腺苷 (ATP) 合成减少，干旱胁迫降低了两个品种的花粉育性。较低的同化供应能力以及ADP-葡萄糖焦磷酸化酶和可溶性淀粉合酶的活性受损是干旱胁迫花药中淀粉水平降低的主要原因。蔗糖合成酶和酸性转化酶活性降低是干旱胁迫花药中蔗糖水平高于水分充足花药的原因，而蔗糖合成酶基因（GhSusA、GhSusB、GhSusD）和酸性转化酶基因（GhINV1、GhINV2）。然而，尽管蔗糖降解在干旱胁迫的花药中受到限制，但干旱花药中的葡萄糖水平高于浇水充足的花药，这可能是由于在干旱胁迫植物中检测到花药 ATP 水平降低导致呼吸下调。此外，