Egg cell-secreted aspartic proteases ECS1/2 promote gamete attachment to prioritize the fertilization of egg cells over central cells in Arabidopsis  

作　　者：Jiahao Jiang Nils Stührwohldt Tianxu Liu Qingpei Huang Ling Li Li Zhang Hongya Gu Liumin Fan Sheng Zhong Andreas Schaller Li-Jia Qu 

机构地区：[1]State Key Laboratory for Protein and Plant Gene Research,Peking-Tsinghua Center for Life Sciences at College of Life Sciences,Peking University,Beijing 100871,China [2]Department of Plant Physiology and Biochemistry,Institute of Biology,University of Hohenheim,Stuttgart 70593,Germany

出　　处：《Journal of Integrative Plant Biology》2022年第11期2047-2059,共13页植物学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.32122014,31991202,31830004,and 32070854);Young Elite Scientists Sponsorship Program by China Association of Science&Technology(Grant No.2019QNRC001);supported by the Peking-Tsinghua Joint Center for Life Sciences;supported by the German Research Foundation(DFG)。

摘　　要：Double fertilization is an innovative phenomenon in angiosperms,in which one sperm cell first fuses with the egg cell to produce the embryo,and then the other sperm fuses with the central cell to produce the endosperm.However,the molecular mechanism of the preferential fertilization of egg cells is poorly understood.In this study,we report that two egg cell-secreted aspartic proteases,ECS1 and ECS2,play an important role in promoting preferential fertilization of egg cells in Arabidopsis.We show that simultaneous loss of ECS1 and ECS2 function resulted in an approximately 20%reduction in fertility,which can be complemented by the full-length ECS1/2 but not by corresponding active site mutants or by secretion-defective versions of ECS1/2.Detailed phenotypic analysis revealed that the egg cellsperm cell attachment was compromised in ecs1 ecs2 siliques.Limited pollination assays with cyclin-dependent kinase a1(cdka;1)pollen showed that preferential egg cell fertilization was impaired in the ecs1 ecs2 mutant.Taken together,these results demonstrate that egg cells secret two aspartic proteases,ECS1 and ECS2,to facilitate the attachment of sperm cells to egg cells so that preferential fertilization of egg cells is achieved.This study reveals the molecular mechanism of preferential fertilization in Arabidopsis thaliana.

关 键 词：Arabidopsis thaliana double fertilization ECS1/2 gamete interaction preferential fertilization 

分 类 号：Q944.44[生物学—植物学]