胡萝卜开花抑制子基因DcFLC的克隆与表达模式

Cloning and expression profiles of flowering suppressor gene DcFLC in Daucus carota

开花是植物由营养生长向生殖生长转变的重要标志。开花抑制子基因FLC是植物春化作用的关键调节基因。为了探明FLC基因在胡萝卜花发育过程中的作用,本研究以黑田五寸胡萝卜为试验材料,克隆得到胡萝卜DcFLC基因的编码序列(CDS),并利用实时荧光定量PCR技术(RT-qPCR)分析盛花期黑田五寸胡萝卜各组织及不同发育状态花中DcFLC基因的相对表达量。结果表明,DcFLC基因的开放阅读框(ORF)长度为660 bp,编码219个氨基酸。DcFLC的相对分子量为2.454×10^(4),理论等电点为9.15,是一个亲水性蛋白质。基于FLC编码的蛋白质氨基酸序列,胡萝卜与拟南芥、结球白菜、油菜、萝卜、杧果、白桦、可可、龙眼、葡萄、核桃等物种的遗传距离较远。盛花期胡萝卜肉质根、叶片和叶柄中DcFLC基因的表达量高于茎和花中DcFLC基因的表达量;花中开花抑制子基因DcFLC的相对表达量随着花的发育呈现先上升后下降再上升的变化趋势。本研究结果为胡萝卜FLC基因的利用和耐抽薹胡萝卜品种选育提供依据。

Flowering is an important symbol of the transformation of plants from vegetative growth to reproductive growth.The flowering suppressor gene FLC is a key regulator of plant vernalization.In order to explore the role of FLC gene in the development of carrot flowers,the coding sequence(CDS)of DcFLC gene was cloned from Kurodagosun carrot,and the relative expression of DcFLC gene in different tissues and flowers with different developmental states of Kurodagosun carrot at full-bloom stage was analyzed by real-time fluorescence quantitative PCR(RT-qPCR)in this study.The results showed that the open reading frame(ORF)of DcFLC gene was 660 bp in length,encoding 219 amino acids.The relative molecular weight of DcFLC was 2.454×10^(4),and the theoretical isoelectric point was 9.15.It was a hydrophilic protein.Based on the amino acid sequence of the protein encoded by FLC,the genetic distance between carrot and Arabidopsis thaliana,Chinese cabbage,rapeseed,radish,mango,birch,cocoa,longan,grape and walnut was far.The expression of DcFLC gene in carrot fleshy roots,leaves and petioles was higher than that in stems and flowers at full-bloom stage.With the development of flowers,the relative expression of flowering suppressor gene DcFLC in flowers showed a trend of increasing first,then decreasing and then increasing.The results of this study provide a basis for the utilization of carrot FLC gene and the breeding of bolting-resistant carrot varieties.