Transcriptomics Analysis on Fertility Conversion in Thermosensitive Genetic Male Sterility Line Zhu1S under High Temperature

Zhu1S is a thermosensitive genic male-sterile (TGMS) line of rice possessing outstanding combining ability and low critical temperature, which has been extensively utilized as a female parent in two-line hybrid ricebreeding. However, the fertility of Zhu 1S during hybrid seed production is frequently affected by high temperature, thus leading to its fertility alteration and aborted hybrid seed production. To understand its fertility conversion mechanism under high temperature, we employed transcriptomics analyses on the anthers of young panicles of Zhu 1S during the fertility alternation sensitivity stage under high (Zhu 1S-H) and low (Zhu 1S-L) temperatures. The results showed that a total of 1119 differentially expressed genes (DEGs) were identified between Zhu 1S-H and Zhu1S-L anthers, including 680 up-regulated and 439 down-regulated genes. Bioinformatics analysis of these DEGs revealed that the high temperature induction caused fertility-sterility conversion in Zhu1S, mainly by decreasing the mRNA abundances of important genes closely related to plant hormone and MAPK signal pathway and transcriptional regulation factors, thereby impeding the growth and development of the anther of Zhu 1S, which ultimately affected the fertility transition of Zhu 1S under high temperature. The protein–protein interaction network analysis indicates that transcription factor OsTIFY11C possibility plays a central role in the fertility transition of Zhu 1S under high temperature.The present studies offer a theoretical foundation for further research into the molecular mechanism underlying fertility conversion in TGMS line Zhu 1S.