Abstract
Tapetum,the innermost layer of the anther wall,provides essential nutrients and materials for pollen development.Timely degradation of anther tapetal cells is a prerequisite for normal pollen development in flowering plants.Tapetal cells facilitate male gametogenesis by providing cellular contents after highly coordinated programmed cell death(PCD).Tapetal development is regulated by a transcrip-tional network.However,the signaling pathway(s)involved in this process are poorly understood.In this study,we report that a mitogen-activated protein kinase(MAPK)cascade composed of OsYDA1/OsYDA2-OsMKK4-OsMPK6 plays an important role in tapetal development and male gametophyte fer-tility.Loss of function of this MAPK cascade leads to anther indehiscence,enlarged tapetum,and aborted pollen grains.Tapetal cells in osmkk4 and osmpk6 mutants exhibit an increased presence of lipid body-like structures within the cytoplasm,which is ac-companied by a delayed occurrence of PCD.Ex-pression of a constitutively active version of OsMPK6(CA-OsMPK6)can rescue the pollen de-fects in osmkk4 mutants,confirming that OsMPK6 functions downstream of OsMKK4 in this pathway.Genetic crosses also demonstrated that the MAPK cascade sporophyticly regulates pollen develop-ment.Our study reveals a novel function of rice MAPK cascade in plant male reproductive biology.
基金项目
National Natural Science Foundation of China(Young Scientist Fund,YSF)(32100288)
Natural Science Foundation for Youths of Jiangsu Province(BK20200558)
Fundamental Research Funds for the Central Universities(ZJ22195005)
维普
万方数据