摘要
梅花(Prunus mume)是我国特有早春木本观赏植物,因其花香清新、花型多样、树姿隽秀深受人们喜爱。梅花品种以直枝类为主,垂枝类和龙游类品种极少,因此株型是梅花育种的一个重要方向。植物HD-Zip III转录因子作为调控分生组织形成和维持的重要转录因子,对枝条发育和株型建成具有重要调控作用。为揭示梅花株型性状形成的分子机理,本研究克隆了梅花PmHB5基因和启动子序列并进行了基因时空表达模式、启动子功能、激素应答和亚细胞定位分析。测序结果表明梅花PmHB5基因编码区长2523 bp,编码840 aa,存在miR165/166的靶位点;PmHB5启动子存在大量的光响应元件、植物激素响应元件以及芽和分生组织特异性表达元件。qRT-PCR结果表明PmHB5基因在茎和叶芽中表达量较高,尤其是形成层和分化木质部组织中最高,且受赤霉素(GA3)、生长素(IAA)、玉米素(ZA)、激动素(KT)和油菜素内酯(BR)等诱导表达。梅花miR165和miR166在木质部、形成层和韧皮部中的表达量和PmHB5基因呈相反趋势。PmHB5启动子驱动GUS活性显示主要在转基因拟南芥花序分生组织、侧芽分生组织、茎和幼嫩叶片的维管组织等细胞分裂与分化活跃的部位表达较高。亚细胞定位表明PmHB5是在细胞核上形式功能的转录因子。本研究明确了梅花PmHB5基因的时空表达及激素应答模式,为深入研究PmHB5参与茎发育的分子机理提供了参考。
Prunus mume(Mei)is an early spring woody ornamental plant native to China and is loved by people because of its fresh flower fragrance,diverse flower types and beautiful plant architecture.However,the majority of varieties of P.mume have upright branches,and only few varieties have weeping or tortuous traits.Thus,the plant architecture is a major direction of breeding in P.mume breeding.HP-ZipⅢ,as important transcription factors regulating the formation and maintenance of meristem,plays critical roles in the regulation of stem development and plant architecture formation.To explore the function and molecular mechanism of the HD-ZipⅢgenes in plant architecture in P.mume,PmHB5 gene and its promoter sequences were cloned,followed by analysis of temporal and spatial expression pattern,promoter function,hormone response and subcellular localization.The sequencing results showed that the coding region of PmHB5 gene was 2,523 bp encoding 840 aa,and there was a target site of miR165/166;PmHB5 promoter has a large number of light response elements,plant hormone response elements and bud and meristem specific expression elements.PmHB5 was highly expressed in stem and leaf buds,especially in cambium and xylem,and responded to a variety of plant hormones such as gibberellin(GA3),auxin(IAA),zeatin(ZA),kinetin(KT)and brassinolide(BR).The expression of miR165 and miR166 in xylem,cambium and phloem showed the opposite trend of PmHB5.The GUS gene driven by PmHB5 promoter in transgenic arabidopsis was mainly expressed in the parts with active cell division and differentiation,such as inflorescence meristem,lateral bud meristem,vascular tissue of stem and young leaves.Subcellular localization showed that PmHB5 functioned in the nucleus as a transcription factor.This study described the temporal and spatial expression pattern and hormone response pattern of PmHB5 in P.mume,which provided a theoretical reference for further study on the molecular mechanism of PmHB5 involved in stem development.
作者
郑唐春
李璐璐
王佳
程堂仁
张启翔
ZHENG Tangchun;LI Lulu;WANG Jia;CHENG Tangren;ZHANG Qixiang(Beijing Key Laboratory of Ornamental Plants Germplasm Innovation&Molecular Breeding,National Engineering Research Center for Floriculture,Beijing Laboratory of Urban and Rural Ecological Environment,Engineering Research Center of Landscape Environment Ministry of Education,Key Laboratory of Genetics and Breeding in Forest trees and Ornamental Plants of Ministry of Education,School of Landscape Architecture,Beijing Forestry University,Beijing 100083,China)
出处
《河北农业大学学报》
CAS
CSCD
北大核心
2022年第5期77-85,F0003,共10页
Journal of Hebei Agricultural University
基金
中央高校基本科研业务费专项资金资助(2021ZY39)
北京市共建项目资助(2020GJ-03).
关键词
梅花
PmHB5
株型
激素响应
表达模式
Prunus mume
PmHB5
plant architecture
hormone response
expression pattern
