Cloing And Analysis Of Expression Of Related Genes Of MAX Pathway In Brassica Juncea Var. Gemmifera Lin.

Brassica juncea var. gemmifera Lin. is a kind of mustard mutants and belongs to Cruciferae Brassica, mainly growing in the region near the Yangtze River. Because it is not commonly grown in other place, the production of Brassica juncea var. gemmifera Lin.is limited and cannot meet the demand for supplying the whole country. However, if we can increase the production, it has significant meaning to commercial popularizing. Utilizing molecular biology techniques, it can be done to extract the gene controlling its lateral bud growth and clear its expression pathway and this research will help to increase the production of Brassica juncea var. gemmifera Lin.Through the analysis of Arabidopsis mutants, researchers found a pathway that regulates lateral bud growth, as known as MAX pathway. This pathway includes regulation of gene MAX1, MAX2, MAX3, MAX4 and interaction among auxins, cytokinins and strigolactone. Currently in Peas, morning glory and rice, the homologous gene has been cloned. On the base of phenotypic and molecular biological characteristics of lateral bud of Brassica juncea var. gemmifera Lin. and mustard, this research mainly focused on the relative gene in MAX pathway. The study of gene regulating lateral bud of Brassica juncea var. gemmifera Lin. is blank now. We utilized wild type Brassica juncea var. gemmifera Lin. and mustard to study their lateral bud regulation and got following results:1. The gene related to MAX pathway of Brassica juncea var. gemmifera Lin.is named eMAX2, eMAX3, and eMAX4 fragment and the ones in mustard is named jMAX2, jMAX3, jMAX4 fragment. The homology with Arabidopsis thaliana is MAX2 84%,MAX3 56%,MAX4 87%. eMAX2 fragment and jMAX2 fragment, eMAX3 fragment and jMAX3 fragment have the exactly same nucleotide sequence, while eMAX4 gene fragment, relative to the jMAX4 fragment, has several point mutations.2. Through the specific gene expression of Actin in Brassica juncea var. gemmifera Lin. and mustard as a reference, by semi-quantitative RT-PCR analysis, we studied the differences of expression mode between eMAX2, eMAX3, and eMAX4 in Brassica juncea var. gemmifera Lin.and between jMAX2, jMAX3, jMAX4 in mustard. The result indicated that the expression of MAX2 gene is higher in mustard than that in Brassica juncea var. gemmifera Lin. And the expressions of MAX3 and MAX4 genes have almost no difference. 3. To clear the effect of auxins, cytokinins and strigolactone to the gene expression mode in MAX pathway, we treated Brassica juncea var. gemmifera Lin. and mustard respectively with auxins, cytokinins and strigolactone, then analyzed with semi-quantitative RT-PCR. The results showed that IAA and ZT have no effects on the genes related in MAX pathway, while applied with GR24, the expression of MAX2 gene increased slightly but the expression of MAX3 and MAX4 genes have no significant changes.