Deficiency of a triterpene pathway results in humidity-sensitive genic male sterility in rice

• Published in: Nature communications 2018-02, Vol.9 (1), p.604-10, Article 604
• Main Authors: Xue, Zheyong, Xu, Xia, Zhou, Yuan, Wang, Xiaoning, Zhang, Yingchun, Liu, Dan, Zhao, Binbin, Duan, Lixin, Qi, Xiaoquan
• Format: Article
• Language: English
• Subjects: 101/58; 101/6; 13; 13/1; 13/44; 14/28; 38; 38/39; 38/77; 42; 631/449/2653/2659; 631/449/2679/1743; 631/449/711; Biosynthetic Pathways - genetics; Coating; Corn; Dehydration; Desiccation; Drying; Fatty acids; Flowering; Gene Expression Profiling - methods; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Germ cells; Grains; Humanities and Social Sciences; Humidity; Intramolecular Transferases - genetics; Intramolecular Transferases - metabolism; Linolenic acid; Male sterility; Microscopy, Electron; multidisciplinary; Mutation; Oryza; Oryza - enzymology; Oryza - genetics; Oryza - metabolism; Palmitic acid; Plant breeding; Plant Infertility - genetics; Plant protection; Plant Proteins - genetics; Plant Proteins - metabolism; Plants (botany); Plants, Genetically Modified; Pollen; Pollen - genetics; Pollen - metabolism; Pollen - ultrastructure; Pollination; Pollination - genetics; Relative humidity; Rice; Science; Science (multidisciplinary); Stearic acid; Triterpene synthase; Triterpenes - metabolism; Wheat
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-03048-8

In flowering plants, the pollen coat protects the released male germ cells from desiccation and damage during pollination. However, we know little about the mechanism by which the chemical composition of the pollen coat prevents dehydration of pollen grains. Here we report that deficiency of a grass conserved triterpene synthase, OsOSC12/OsPTS1, in rice leads to failure of pollen coat formation. The mutant plants are male sterile at low relative humidity (RH 80%). The lack of three major fatty acids in the pollen coat results in rapid dehydration of pollen grains. We show that applying mixtures of linolenic acid and palmitic acid or stearic acid are able to prevent over-dehydration of mutant pollen grains. We propose that humidity-sensitive genic male sterility (HGMS) could be a desirable trait for hybrid breeding in rice, wheat, maize, and other crops. In flowering plants, the pollen coat surrounds the male germ cells and protects against dehydration, damage and pathogen attack. Here, the authors show that a deficiency in terpenoid synthesis results in rice pollen over-dehydration and leads to a humidity-sensitive conditional male sterile phenotype.