Small RNA profiles of the rice non-pollen male sterile line Wuxiang S reveal miRNAs involved in the fertility transition. Oryza sativa Indica Group

Illumina sequencing was employed to examine the expression profiles of rice anther miRNAs from the a non-pollen male sterile line Wuxiang S (WXS), one of photo-thermo sensitive genical male sterile (PTGMS) line rice, during in the fertility transition stage. A total of 493 known miRNAs and 273 novel miRNAs were identified during rice anther development. Based on the number of sequencing reads, a total of 26 miRNAs were discovered to be significant difference expression between WXS(S, Sterility) and WXS(F, Fertility), and the results were partially validated by qRT-PCR. Among these, 11 miRNAs were decreased and 15 miRNAs were increased in WXS(S) compared with WXS(F). The expression patterns for targets of osa-miR156a-j, osa-miR3879, osa-miR159c/d/e, osa-miR171a/c/e/i, osa-miR398b, osa-miR164d, osa-miR528 and osa-miR408 were selectively examined, and the results showed that there was a negative correlation on the expression patterns between miRNAs and their targets. These targets have previously been reported to be related with pollen development and male sterility, suggesting that miRNAs might act as regulators of rice anthers. Furthermore, miRNA editing events were observed. The U-to-C and U-to-A editing phenomenon was validated by molecular cloning and sequencing. Overall design: Examine small RNA profiles change of four tissues of the rice non-pollen male sterile line Wuxiang S under two different environments.