Bioinformatic Analysis Of Linkage Relationship Between Genes Of Herbicide Resistance And Nuclear Male Sterility In Arabidopsis Thialiana

Arabidopsis thaliana, a Cruciferous grass, is a model plant for molecular biology and has a close genetic relationship with brassicas. The genome sequencing was completed successfully al the end of 2000, which provided rich gene resource for biological research and application. Full use of these gene resources and searching the valuable genes for crop genetic improvement will become the targets of research. Crop resistance to herbicide had been used to control weeds comprehensively in agricultural production. Herbicide resistance was also used to remove '50 percent fertile plants in the transgenic population of nuclear male sterile line, in which the herbicide resistance gene and male sterile gene were linked tightly by genetic engineering technique. Whereas, the safety of transgenic crops and the limit of available gene resources at present restrict the transgenic research and application .In order to bypass the safety question of transgenic crops and undermine the gene resources, we adopted the bioinformatic method to search the male sterile genes linked to herbicide resistance gene in plant genome, for solution of 50 percent fertility of nuclear male sterile line during production of hybrid seeds, this natural kind of linkage relationship is a new idea.Because there is the Arabidopsis sequence information in the public database and the annotation of Arabidopsis genome has been consummated primarily, the Arabidopsis genome was chosen as the data resource for data mining. We scanned the chromosome region of the three herbicide resistance genes (ALS , EPSPs, CESA) , and searched the male development related genes tightly linked to the herbicide resistance gene by analyzing the arabidopsis related database in silico. At the same time, the Arabidopsis expression analysis information was searched, mainly focusing on the expression data in the Arabidopsis EST database and microarray database to look for the male or flower development related gene. After analysis the genes around the three herbicide resistance genes, although a male sterile gene DAD] was found, which linked to the herbicide gene EPSPs, no gene was discovered around the other two genes. The expression data analysis showed that there were some male or flower development related genes around them.These genes could be candidate genes for further biological experiments.The creation and application of mutants is an effective method for annotation of gene functions. Because the herbicide resistance transformed brassica was produced by point mutation of ALS gene in our library, genes around the ALS gene were selected as targets to screen the male sterile mutant. Among 124 mutants, no mutant exhibited male sterile trait. Moreover, the hpRNA post-transcription gene silencing vector was constructed with Arabidopsis male sterile gene and introduced into Agrobacteria to transform excised brassica cotyledon, the positive plants were selected by PCR analysis.For the further study of gene function, more resistance genes and male sterile genes will be discovered, so linkage relationship of the two kinds of genes will be expected in the future, which will provide valueable resources and wide choose of crop genetic improvement.