菜薹花芽分化及BrcuFLC基因的克隆与表达

Study on Flower Bud Differentiation and Cloning and Expression of BrcuFLC in Brassica campestris L.ssp.chinensis (L.) Makino var.utilis

通过制作石蜡切片研究了菜薹[Brassi cacampestris L.ssp.chinensis （L.） Makinovar.utilis Tsen et Lee]早熟品种‘油青四九’和晚熟品种‘油青甜菜心80天’的花芽分化过程，结果表明，当展开2-3片真叶时花芽分化开始启动。用已报道的拟南芥Flowering locus C（FLC）基因和FRIGIDA（FRI）基因的保守区域设计引物，通过RT-PCR的方法从两个菜薹品种中均克隆得到了两个决定开花的关键基因，并命名为BrcuFLC（GenBank登录号为EF138603）和BrcuFRI（GenBank登录号为EU700362）。半定量式RT-PCR表达分析表明，BrcuFLC基因在早、晚熟菜薹品种的不同发育时期表达存在差异，表达量随真叶数增加而逐步减少，但在晚熟品种中BrcuFLC表达量降低幅度小；BrcuFRI则在早、晚熟品种的所有阶段表达都较低。BrcuFLC在菜薹不同部位表达的情况不同，在茎、叶中的表达强，花次之，根中表达较弱；而Brcu-FRI在早、晚熟品种根中的表达量明显高于其它3个部位。

The morphogenesis of the flower buds of the early and late varieties of flowering Chinese cabbage was found to be almost the same.All flower buds began to differentiate at the 2 to 3 leaves stage.Based on the conserved sequence of Flowering locus C（FLC）and FRIGIDA（FRI）gene of Arabidopsis thaliana,a 612 bp fragment with an ORF encoding 198 amino acids and a 463 bp cDNA fragment were amplified by RT-PCR from cDNA of flower stalk and were named BrcuFLC（GenBank accession number：EF138603）and BrcuFRI（GenBank accession number：EU700362）.Semi-quantitative RT-PCR analysis showed that the expression of BrcuFLC was different in the early and late varieties.With the increase of the leaves,the BrcuFLC expression of two varieties were decreased,but the decrease quantity was not obvious in the late variety.The expression of BrcuFRI was very low in both of two varieties.BrcuFLC would transcript differently at various sites.The intensity of the stem and leave was more stronger than that of flower and root,but for the BrcuFRI expression,the intensity of the root was the most strong in four organs.