Expressional Analysis Of TCP Family Transcriptional Factor BcBRC1 Gene And Tillering Trait Genetic Analysis In Non-Heading Chinese Cabbage

Tillering was a special kind of branches during the growth and development in higher plant,and the development of branches played an important role in plant morphogenesis.Branches—one of important characteristics in crops determined producing seed rate and further affected the productivity of crop.The number of tillering in rice associated closely with the productivity,so,apprently,the control of branches was important for improving plant.At the same time,if tillering genes were cloned successfully in Brassicacrae plant,it woud be a giant economic value.Study of TCP transcriptional factor family in non-heading Chinese cabbage contributed to explain tillering molecular mechanism in non-heading Chinese cabbage.In this study,TCP transcriptional factor gene was cloned from cDNA library of non-heading Chinese cabbage by homology-based cloning,and the gene expressed differently in tissue of non-heading Chinese cabbage especially before and after tillering,so we designed the primer and gained the gene full-length.At last,we reported that the expression of the gene was affected by sucrose treatment,so the relationship between the gene and the tillering was analyzed.Moreover,we conducted the quantitative genetic analysis of the F2 and F2:3 segregation generations and estimated gene effect,genetic model and heritability of tillering trait of parent and related generation.The main results are as follows:1?BcBRC1 gene which was a member of TCP family transcriptional factor was cloned from cDNA library of non-heading Chinese cabbage(Brassica campestris ssp.chinensis Makino).The full-length cDNA of BcBRCl was 1287 bp in length and encoded 428 amino acids,which contained a conserved TCP domain that was necessary for it to dimerize and combine DNA molecule.The deduced amino acid sequence of the BcBRC1cDNA revealed that it has high homology to AtTCP18 members in Arabidopsis species.Reverse transcription-PCR(RT-PCR)results showed that there was a significant increase of the BcBRC1 in young shoot of non-heading Chinese cabbage before its tillering stage and that there was a significant decrease after its tillering stage.These findings suggested that BcBRC1 may play prominent roles in tillering of non-heading Chinese cabbage.2?We observed that phenotype of non-heading Chinese cabbage changed after sucrose treatment.It showed that the buds form earlier and that the number of buds was more after sucrose treatment,which consistent with the observation gained from microphoto in tissue.RT-PCR results showed that the expression of BcBRC1 and MAX2 gene was down-regulated by sucrose,which indicated that BcBRCl gene may involve in tillering of non-heading Chinese cabbage.3?In this study,two varieties of non-heading Chinese cabbage-'Maertou' and'Suzhouqing' were crossed to gain the F2 and F2:3 segregation populations which were analyzed by single generation segregation model method.It showed that the tillering trait in non-heading Chinese cabbage was mainly controlled by two couple major genes which had additive and dominance interaction.The heritability of the major genes was significantly higher than the heritability of the polygenes,which suggested that the tillering of generation F2 and F2:3 was mainly controlled by major genes and less affected by environment and polygenes.