Find in Library

Multiple allele-inherited male sterility has been widely used by breeders of Brassica rapa L. ssp. pekinensis, but the molecular mechanisms of male sterility are not yet clear. In this study, we isolated the full-length cDNA of a new gene (not included in the Brassica database). This gene, comprising 1 054 bp, encodes a 39.99 kDa protein with a Gly-Asp- Ser-Leu (GDSL)-lipase domain that is a member of the lipolytic protein GDSL family. The sequence of candidate gene is the most similar to extracellular lipase 6 (EXL6) of Arabidopsis and was therefore designated BrEXL6 and submitted to NCBI (accession No. JX131630.1). Reverse transcription semi-quantitative PCR and Western blot analysis showed that BrEXL6 and its encoded protein were significantly more expressed in fertile buds than in sterile buds. Quantitative PCR and in situ hybridization showed that BrEXL6 was highly expressed in the anthers of fertile buds, especially anthers at the pollen-development stages, but only weakly expressed in other tissues and floral organs of fertile plants and whole sterile plants. These results suggest that BrEXL6 is a pollen development-related gene. The results of this study provide clues for understanding the mechanisms underlying multiple allele-inherited male sterility.