2025/04/18 by Hiroshi Wada, Yuto Hatakeyama, Rosa Erra‐Balsells +6 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Photosynthetic Processes and Mechanisms #Plant Molecular Biology Research #Plant Reproductive Biology
paper · pdf · doi:10.1038/s42003-025-08018-7
openalex publication_date 2025/04/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
In angiosperm, successful pollen adhesion and hydration on the stigma are essential for pollen germination and tube elongation. Self-pollinated grass plants, such as rice, exhibit viscous 'pollen exudation' prior to adhesion; however, its cellular dynamics, including their chemical composition, remain unknown. Here, we revisit pollen exudation in rice to find that pollen grains showed 'Roly-poly toy'-like rocking motion on the exudates to lead pollen adhesion. Single-cell metabolomics revealed that exudates were composed of high content of sugar together with fatty acids and redox-related metabolites, different from mature pollen grains and stigma cells. And hence, these solutes might participate in osmotic and molecular signaling in stigmatic apoplast, increasing the fluid viscosity. Taken together, it is concluded that the unique behaviour observed in rice pollen grains might play a crucial role on optimal self-positioning and adhesion prior to pollen germination, resulting in the rapid self-pollination.