龙眼胚性愈伤组织中TFL1基因克隆及其表达分析

Cloning and Characterization of TFL1 Family Genes from Embryogenic Callus in Dimocarpus longan Lour.

TFL1是FT/TFL1家族的一个成员,TFL1通过对顶端分生组织的维持从而延迟了植物开花时间。以龙眼松散型胚性愈伤组织为材料,采用RT-PCR结合RACE法克隆了TFL1的c DNA全长和g DNA序列,命名为Dl TFL1。Dl TFL1全长866 bp,编码175个氨基酸。Dl TFL1的g DNA序列长为1 492 bp,由3个内含子和4个外显子组成。Dl TFL1为稳定的亲水蛋白,没有信号肽与跨膜结构,含有PEBP功能保守结构域。进化树分析表明,Dl TFL1与小油桐、葡萄、毛果杨等植物TFL1的亲缘关系较近。q-PCR表明,Dl TFL1在"四季蜜"龙眼不同组织部位中的表达差异明显,在花蕾中的表达量最高,在根、叶和花中表达量较低,在其他部位甚至不表达。说明Dl TFL1是植物TFL1同源基因,可能具有抑制开花作用,对"四季蜜"龙眼花早期的器官发育可能有促进作用。

TFL1 is belonging to the FT/TFL1 family, and it is involved in delaying the plant flowering time through maintaining the apical meristem. The RT-PCR combined with RACE method was used to obtain the complete c DNA and g DNA sequences of Dl TFL1 from embryogenic callus in Dimocarpus longan. The complete c DNA sequence of Dl TFL1 was 866 bp, encoding 175 amino acids. The g DNA sequence of Dl TFL1 was 1 492 bp, contains three introns and for exons. Dl TFL1 was stable and hydrophilic proteins, without signal peptides and Tran membrane structures, had the PEBP protein function domain. Phylogenetic tree analyses indicated that Dl TFL1 has a close genetic relationship with Jatropha curca、Vitis vinifera、Populus trichocarpa.q PCR result indicated that the expressing of Dl TFL1 was very differential in ＂Sijimi＂different tissues, it expressed at the highest level in the flower bud, lower in root, leaf and flower, but not expressing in other tissues. Dl TFL1 is a plant TFL1 homologous gene, may have inhibitory effect on flowering, it may promote the development of early flowers of＂Sijimi＂longan.