Differential gene expression profiling of Ogura CMS line and its maintainer in radish (Raphanus sativus L.)

Abstract

Cytoplasmic male sterility (CMS) is a maternally inherited trait, which becomes an important way in heterosis breeding to simplify the seed production procedures and reduce the production cost. Cytological observation of pollen development stages showed a clear difference between the newly developed CMS line and its maintainer; the profiling comparisons between floral buds of CMS line and its maintainer were conducted using differential display reverse transcription PCR (DDRT-PCR) technology. Thirty genes were up-regulated and sixty genes were down-regulated in newly developed CMS line when compared with its maintainer. These genes were involved in cell wall biosynthesis and regulation, transporter and ion channel, flower development and protein metabolism, etc. Expression patterns of six genes encoding RsCAM6, RsGPI, RsPMEI, RsRac, RsCHS, and RsSTP9 were verified by RT-PCR and qRT-PCR in different development stage of floral buds and different organs of CMS line and its maintainer. The expression level of RsRac was higher in stamens and microspores of CMS line than in maintainer. In comparison, the expression levels of the other five genes in CMS line were lower compared with maintainer. This expression profile suggests that these genes played important roles in the development of the pollen and may be closely related to male sterility. The results observed in this study will contribute to understanding the mechanism of pollen abortion during CMS in radish.