白菜春化相关基因BcFLC的克隆及表达研究

运用同源基因克隆法从‘上海青’白菜（Brassica campestris ssp. chinensis var. ommunis ‘Shanghai Qing’）和‘四九’菜薹（var. parachinensis‘Sijiu’）叶片中分离到FLC的同源基因BcFLC的编码序列、启动子以及内含子1序列；序列比对发现，二者编码的核苷酸序列几乎完全一致，而且启动子及内含子1序列也无实质性差异；对‘上海青’进行人工低温春化处理，BcFLC1基因在‘上海青’茎尖的表达随着低温处理时间的延长逐渐减弱，低温处理20 d时BcFLC1基因的表达已经非常弱，低温处理30 d时，表达已检测不到，花芽分化石蜡切片也表明，低温处理20 d，茎尖已开始向生殖状态过渡。BcFLC2基因在‘四九’菜薹未现蕾之前的叶片中有强表达，而现蕾之后叶片中则检测不到。

Cloning and Expression Analysis of Vernalization-related Gene BcFLC in Brassica campestris

In order to investigate the flowering repressor geneFLC in Chinese cabbage-pak-choi, by homologous cloning and RACE, vernalization related gene BcFLC1 andBcFLC2 were respectively isolated from Brassica campestris ssp. chinensis var. communis ‘Shanghai Qing’ andBrassica campestris ssp. chinensis var. parachinensis ‘Sijiu’. The results of alignment indicated that there was no difference between the coding sequences (CDS) of BcFLC1 and BcFLC2, and the nucleotide sequence of promoter and intron 1 of them ere of no substantial difference. RT PCR analysis showed that the expression of BcFLC1 in the shoot apical meristem of ‘Shanghai Qing’was reduced gradually by the time of artificially vernalization at 4℃, and it got a very low level after 20 days and was undetectable after 30 days. The paraffin section also proved that 20 days cold treatment was enough for the apical meristem transforming to reproductive development. BcFLC2 was strongly expressed in the leaf of flowering Chinese cabbage‘Sijiu’ before floral buds appear; however, the expression of BcFLC2 was undetectable after floral buds’ appearance.