杜致辉 杨澜 姚新转 陈之林

摘  要：FT（FLOWERING LOCUS T）基因是植物開花调控过程中的关键整合基因。为探明黑喉石斛（Dendrobium ochreatum）FT同源基因功能及其在黑喉石斛嫩茎开花过程中扮演的角色，本研究以黑喉石斛为试验材料，基于转录组测序结果，克隆得到黑喉石斛FT同源基因，命名为DoFT1。DoFT1基因编码区长度为537 bp，共编码178个氨基酸;生物信息学分析结果表明，该基因编码的蛋白属于PEBP家族蛋白，其含有关键保守氨基酸位点Tyr84和11个连续保守氨基酸残基序列，为FT同源基因;进化树分析结果显示，DoFT1氨基酸序列与铁皮石斛和小兰屿蝴蝶兰同源基因亲缘关系较近;Real-time PCR分析结果显示，DoFT1主要在黑喉石斛叶片部位表达，其表达量在花芽开始分化阶段出现上调，并在花芽成熟期达到峰值后呈下降趋势;将DoFT1导入烟草中超量表达，可以显著促进烟草提前开花。

关键词：黑喉石斛;DoFT1基因;嫩茎开花;成花诱导中图分类号：Q789      文献标识码：A

Expression Pattern Analysis of Dendrobium ochreatum DoFT1 Gene During Flower Development and Its Functional Verification

DU Zhihui¹， YANG Lan¹， YAO Xinzhuan²， CHEN Zhilin^1*

1. Guizhou Horticulture Institute， Guizhou Academy of Agricultural Sciences， Guiyang， Guizhou 550006， China; 2. Tea College， Guihzou University， Guiyang， Guizhou 550025， China

Abstract： TheFLOWERING LOCUS T （FT） gene plays a key role in integrating flowering signals in plants.To study the function of the FT homologous gene and its role in tender stem flowering ofDendrobium Ochreatum， theFT homologous gene， named asDoFT1， was cloned from Den. Ochreatumon the basis of transcriptome sequencing results.DoFT1 contained a 537 bp open reading frame which encoding 178 amino acids. Bioinformatic analysis showed that the DoFT1 belonged to the PEBP family， the conserved key amino acid residue Tyr84 and 11-AA stretch of FT homologs were identified in DoFT1. Phylogenetic tree results showed that DoFT1 was closely related to DcFT inDendrobium candidum and PeFT inPhalaenopsis Equestris. Real-time PCR results indicated that the expression ofDoFT1 was mainly located in leaf tissues， and its expression level was up-regulated during the flower bud differentiation phase， then showed a downward trend after reaching its peak at the flower bud phase. Over-expression ofDoFT1 in transgenic tobacco plants resulted in earlier flowering compared to wild-type plants.

Keywords： Dendrobium ochreatum;DoFT1gene; tender stem flowering; flower induction

DOI： 10.3969/j.issn.1000-2561.2021.04.006

黑喉石斛（Dendrobium ochreatum）是兰科（Orchidaceae）石斛属（DendrobiumSw.）多年生附生草本植物^[1]，属于春石斛。相比于大多石斛只能在2年生老茎上开花，黑喉石斛在新长出的嫩茎上就能抽出花序并开花^[2]，其开花时间明显早于其他春石斛，是珍贵的育种亲本，也是研究石斛早开花机理的重要材料。

花期调控是石斛生产中的关键技术，也是近年研究的热点^[3]。花发育主要分为成花诱导、花发端及花器官发育3个阶段。其中，植物从营养生长向生殖生长的转换即成花诱导是植物发育中最显著的过程，也是植物繁殖的关键事件^[4-6]。……