Qian Dong, Li Tian, Zheng Chen, Wang Muxuan, Chen Shuyuan, Li Chengying, An Jiale, Yang Yang, Niu Yue, An Lizhe, Xiang Yun
MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
Nat Commun. 2025 Apr 17;16(1):3642. doi: 10.1038/s41467-025-58869-1.
Global warming intensifies extreme heat events, threatening crop reproduction by impairing pollen development, germination, and tube growth. However, the mechanisms underlying pollen heat responses remain elusive. The actin cytoskeleton and actin-binding proteins (ABPs) are crucial in these processes, yet their roles under heat stress are poorly understood. Here, we identify a mutant, pollen germination sensitive to LatB (pgsl1), via forward genetic screening. PGSL1 encodes a heat-stable, plant-specific ABP that binds and stabilizes actin filaments (F-actin), preventing heat-induced denaturation. High temperatures reduce F-actin content but promote bundling in pollen tubes. Notably, pgsl1 mutants exhibit decreased F-actin abundance and bundling under heat stress compared to wild-type plants. These findings highlight PGSL1 as a key regulator of actin dynamics, essential for pollen heat tolerance, offering potential strategies to enhance crop resilience in a warming climate.
全球变暖加剧了极端高温事件，通过损害花粉发育、萌发和花粉管生长来威胁作物繁殖。然而，花粉热响应的潜在机制仍然不清楚。肌动蛋白细胞骨架和肌动蛋白结合蛋白（ABP）在这些过程中至关重要，但它们在热胁迫下的作用却知之甚少。在这里，我们通过正向遗传学筛选鉴定出一个对LatB敏感的花粉萌发突变体（pgsl1）。PGSL1编码一种热稳定的、植物特有的ABP，它结合并稳定肌动蛋白丝（F-肌动蛋白），防止热诱导的变性。高温会降低花粉管中F-肌动蛋白的含量，但会促进其成束。值得注意的是，与野生型植物相比，pgsl1突变体在热胁迫下表现出F-肌动蛋白丰度降低和成束减少。这些发现突出了PGSL1作为肌动蛋白动力学的关键调节因子，对花粉耐热性至关重要，为在气候变暖的情况下提高作物抗逆性提供了潜在策略。
