Putting the brakes on pollen wall development:A conserved negative feedback loop regulates pollen exine formation in flowering plants  

作　　者：Yuan Zhou Anna A.Dobritsa 

机构地区：[1]Department of Molecular Genetics,Ohio State University,Columbus,OH 43210,USA

出　　处：《Molecular Plant》2023年第9期1376-1378,共3页分子植物（英文版）

基　　金：the US National Science Foundation grant MCB-2240972.

摘　　要：Pollen grains are covered by a complex multi-layered structure,the pollen wall.Exine,the outermost layer of this wall,is made from the biopolymer sporopollenin that exhibits remarkable physical and chemical stability.In different plants,exine,which shields pollen from harsh environmental stresses,has very diverse morphologies and forms different patterns(Wang and Dobritsa,2018).It also contributes to pollination,pollen–stigma interaction,pollen hydration,and eventual release of the pollen tube.Formation of exine begins after male meiosis when four microspores are arranged in a tetrad configuration and enclosed by the callose wall(Ariizumi and Toriyama,2011).At this stage,microspores secrete primexine,the precursor of exine that accumulates between the microspore plasma membrane and the callose wall,providing a scaffold for exine patterning(Wang et al.,2021).As the callose wall gradually gets degraded,sporopollenin is secreted by the nearby tapetal cells and deposited onto the primexine template to form mature exine.This process requires coordination of activities between microspores and the surrounding tapetum.

关 键 词：TEMPLATE CONSERVED POLLEN 

分 类 号：Q94[生物学—植物学]