FT/TFL1-like基因在板栗一次花和二次花发育中的表达分析

Expression Analysis of FT/TFL1-like Genes in Primary and Secondary Flowering of Chinese Chestnut

板栗的雌雄花存在春季和夏秋季两次开花的现象,对产量有决定性影响。FT/TFL1基因在植物成花转变的过程中有着非常重要的调控作用,目前该基因在板栗花发育中的表达模式及功能尚不明确。本研究在板栗基因组中鉴定出5个FT/TFL1-like基因,通过生物信息学的方法,系统地对板栗FT/TFL1基因的理化性质、进化关系、保守基序以及基因的表达模式进行分析。结果表明:板栗FT/TFL1基因均具有PEBP保守结构域,开放阅读框为513~570 bp,编码170~189个氨基酸,外显子数目为3~4个。系统进化分析将FT/TFL1基因分为3个亚类:TFL1-like、FT-like和MFT1-like。基因表达分析显示:CmFT基因在板栗的雌雄花的表达较高;在板栗一次花和二次花的表达分析显示,CmFT基因在两次发育时期都具有较高的表达,其中在雄花序的发育进程表现下降的趋势,相同发育时期一次花的表达均高于二次花的表达;CmFT在雌花簇的发育进程呈上升趋势,相同发育时期一次花的表达低于二次花。本研究表明,在FT/TFL1-like基因家族中,FT基因是参与调控板栗雄花序和雌花簇形态建成的重要基因,通过探讨板栗FT/TFL1基因在一次花和二次花的表达分析,以期进一步为板栗花发育建成与调控提供理论依据。

A phenomenon that Chinese chestnuts bloomed twice per year in the spring and summer or the beginning of the fall,contributes to the yield significantly.The FT/TFL1-like genes play the key roles in floral initiation and morphogenesis.However,the knowledge of its expression profiles and function in flowers of the Chinese chestnuts is still limited.Five FT/TFL1-like genes were identified and the physical and chemical properties,evolutionary relationships,conservative motifs,and gene expression patterns of those genes were systematically predicted and analyzed in the Chinese chestnut genome by bioinformatics methods.The results showed that the FT/TFL1genes had a conserved domain of PEBP,encoded 170 to 189 amino acids with open reading frame of 513~570 bp and the number of exons ranges from 3 to 4 in the genome of Chinese chestnuts.Phylogenetic analysis divided the FT/TFL1 genes into 3 subgroups,including TFL1-like,FT-like and MFT1-like subgroups.Additionally,expression analysis showed that the CmFT gene was mainly expressed in staminate catkin and female flower.The comparative expression analysis of the primary flower and the secondary flower showed that the CmFT gene was highly expressed during the developmental stages both in primary and secondary flower,showing a downward expressed trend in the developmental stage of the staminate catkin.The CmFT gene showed an upward expressed trend during the developmental period of female flowers,and the expressions of primary flowers were higher than secondary flowers in the same stages.This study revealed that FT genes play an important role in regulating the formation of staminate catkin and female flower,and the expression analysis of FT/TFL1 gene in primary and secondary flowers is expected to provide a basis information for further studies in flower development and regulation of Chinese chestnuts.