北京大学瞿礼嘉团队在研究中取得进展。他们开发出两步自花授粉机制使十字花科植物的育性最大化。该研究于2025年4月14日发表于国际一流学术期刊《细胞》杂志上。

通过跟踪拟南芥授粉的时间进程，研究组观察到花粉主要集中在未开放花的柱头外侧区域。值得注意的是，在花开放约7小时后，花闭合，从而将花药压向柱头的中心区域进行第二次自花授粉。这两步自花授粉导致花粉沉积加倍，这在花粉限制条件下显著提高了胚珠靶向率，提高了育性，这在花药开裂缺陷突变体myb108和环境胁迫条件下得到了证明。对配子相互作用缺陷突变体hap2/gcs1和dmp8 dmp9的分析表明，授粉事件的及时分离促进了受精恢复效率。在其他两种自花授粉中观察到类似的两步授粉，但在异交的芸苔科物种中没有观察到。这种机制代表了在不利条件下，以自花授粉为主的一年生植物最大限度地提高生育力的生殖保证策略。

据悉，自交亲和植物的自花授粉通常发生在开花之前。

附：英文原文

Title: A two-step self-pollination mechanism maximizes fertility in Brassicaceae

Author: Pu Liu, Xin Quan, Zihan Song, Wenhao Li, Yuan Wang, Hongya Gu, Daoxin Xie, Weicai Yang, Thomas Dresselhaus, Sheng Zhong, Li-Jia Qu

Issue&Volume: 2025-04-14

Abstract: Self-pollination in self-compatible plant species often occurs prior to flower opening. By tracking the temporal progress of pollination in Arabidopsis, we observed that pollen predominantly targets the lateral region of the stigma in unopened flowers. Notably, approximately 7 h after flower opening, flowers close, thereby pressing anthers toward the central region of the stigma for a second self-pollination. This two-step self-pollination results in a doubling of pollen deposition, which significantly increases the ovule-targeting ratio and improves fertility under pollen-limiting conditions, as evident in the anther-dehiscence-defective mutant myb108 and under environmental stress conditions. Analysis using gamete-interaction-defective mutants hap2/gcs1 and dmp8 dmp9 revealed that the timely separation of both pollination events promotes fertilization recovery efficiency. A similar two-step pollination was observed in two other self-pollinating but not in outcrossing Brassicaceae species. This mechanism represents a reproductive assurance strategy in predominantly self-pollinating annuals to maximize fertility under unfavorable conditions.

DOI: 10.1016/j.cell.2025.03.021

Source: https://www.cell.com/cell/abstract/S0092-8674(25)00294-6