Identification And Expression Analysis Of The Genes Related To The Multiple-Allele-Inherited Male Sterility In Chinese Cabbage (Brassica Rapa L. Ssp. Pekinensis)

To investigate molecular-sterility mechanisms of multiple allele of geneticallytransmitted, we use nuclear male sterile of Chinese cabbage male sterility "dual line AB01"fertile plants (MsfMs) and the flower buds of sterile plants (MsMs) as test materials, thoughsuppression subtractive hybridization (SSH) to screen out the differentially expressed genesbetween he sterile and fertile materials, and clone a lipase GDSL gene called BrEXL6bymolecular biology techniques. The gene is closely related to male sterility of Chinese cabbage.And spatial and temporal expression patterns expression of BrEXL6by real-time fluorescentquantitative RT-PCR(qRT-PCR). The main conclusions are as follows:1. In this study, two cDNA libraries were constructed using the flower fertility andsterility buds of “AB01” by suppression subtractive hybridization technique. Twenty twodifferentially expressed genes were obtained from the reverse library in which fertile plantswere determination plants and three differentially expressed genes were obtained from theforward library in which sterile plants were determination plants2. In this study,25homologous sequences of EST include7of flowerdevelopment-specific expression genes,5lipid metabolism related genes,3reactive oxygenand energy metabolism genes,3photosynthesis and Chloroplasts genes,7gene-related withgenes of the NCBI database but the function is unknown..3. A fertility-related gene, BrEXL6, were separated and cloned and the full-lengthcDNA sequence were gained in this study.4. The full-length cDNA of BrEXL6is1057bp, the largest open reading frame is1032bp,encoding331amino acids. BrEXL6cDNA gene sequence is homologous with ArabidopsisGDSL lipase EXL-6sequence by searching in BLAST datebase, the similarity is the highest,reach to95%5. A phylogenetic tree including BrEXL6and CDS lipase gene sequences of otherplants in GneBank database was construct using MEGA3.1software,the system tree can bedivided into three branches, BrEXL6genes gathered in the first branch, most other genes inthis branch are mostly expressed in pollen or bud, so we can preliminary indicated thatBrEXL6may be a pollen-specific lipase gene.6. In order to determine the gene expression pattern of BrEXL6, qRT-PCR techniquewas used to detect its sterile expressed condition in roots, stems, leaves lines. The resultsshowed that the BrEXL6gene was only expressed in the buds of fertile lines, but nothingexpression were found in the sterile plants. So we can concluded that BrEXL6is related to thefertility of cabbage.7. Expression analysis showed that this gene is firstly expressed in the bud of Stage IIand the highest expression were in the Stage IV and Stage V. That show BrEXL6genes play arole in Stage IV and Stage V.8. Analysed the differentilly expression among mature buds, petals, sepals, pistil andstamen organization by qRT-PCR, the results showed that BrEXL6got a high expression only in stamens, but did not express in the other parts of the flower buds, So, BrEXL6may be ananther-specific gene.