The Study Of BnaSOT12 Gene On Plant Stress In Brassica Napus

Sulphotransferase (SOT, EC 2.8.2.-) is an important protein family, widespreads in plants and animals, catalysing transfer reaction of sulfonic acid group from donator to substrate, so that the substrate occurs sulfonamide acidification. Studies shows Arabidopsis contains 22 AtSOT genes encoding SOT, wherein, the expression of the AtSOT12 can be greatly enhanced by salt, osmotic pressure and hormones. And the germination ratio of T-DNA knockout mutants(sot 12) of AtSOT 12 shows highly sensitive to NaCl and abscisic acid (ABA). In this study, we analysed the distribution and classification of SOT protein family in brassica rapa, brassica oleracea and Brassica napus L. Accroding to the structure of proteins and genes, we selected three BnaSOT12 genes of Brassica napus as the object of this study. By constructing BnaSOT12 over-expression vector and transforming into the Arabidopsis and Brassica napus, we obtained the following results:1. Analysis of the chinese cabbage genome shows that 56 genes encoding BraSOT protein exist in cabbage,53 genes among of them can be located on the chromosomes of cabbage. But the distribution of genes in the chromosome is uneven, chromosome 7 and 9 containing more BraSOT genes, no BraSOT show up on chromosome 5.56 Arabidopsis genes could be classified into nine subfamilies. Most of BraSOT genes contains no intron.2. Analysis of brassica oleracea indicates that its genome has 33 genes of encoding BolSOT protein and can be located in the nine chromosomes, the most of them intensive on the chromosome 3 and 6. But the classification of 33 BolSOT proteins are much dispersed, most among them are subfamily ?, not including homogenous proteins to subfamily ? and ?? in Arabidopsis. Most of BolSOTs do not contain introns, and the length of each gene is quite different.3. Analysis of Brassica napus shows that 115 genes encoding BnaSOT protein exist in Brassica genome. Most of these genes spread in A07, A09, C06 and C09 chromosomes. While, the homologous gene of AtSOT 12 number is 13, indicating that gene in Brassica napus were copied and multiplied, suggesting that it probably has important biological functions. By comparing the gene structure and protein structure, we determined three genes shows the highest similarity with AtSOT12 in structure:BnaC02g35150D, BnaA09g53490D, BnaA09g19440D, named respectively as BnaSOT12a?BnaSOT12b? BnaSOT12c, for the experiment research object.4. Constructed the BnaSOT12a, BnaSOT12b, BnaSOT12c gene overexpression vector, respectively, and Col-0 wild-type Arabidopsis were transformed. Salt resistance experiments on mutant showed that overexpression of BnaSOT12a gene in Arabidopsis, the transgenic plants can increase stress tolerance to NaCl.5. Transformed Brassica napus by pFGC5941::35S:BnaSOT12a vector, the two regeneration system from hypocotyls and cotyledon were used.9 resistant plants of Xiangyou-15 Brassica napus were obtained by method of cotyledon Agrobacterium transformation and the ratio is 0.77%; we used two materials of Xiangyou-15 Brassica and Brassica zhongshuang -6 napus by the regeneration system from hypocotyls, in the process of producing callus and adventitious buds, the Brassica zhongshuang -6 napus exhibits stronger differentiation than Xiangyou-15.