铁皮石斛14-3-3基因家族鉴定及表达分析

Identification and Expression Analysis of 14-3-3 Gene Family in Dendrobium officinale

【目的】14-3-3蛋白,亦称通用调节因子(GRF),由多基因家族编码,在植物生长发育和逆境应答发挥关键的作用。鉴定铁皮石斛(Dendrobium officinale)GRF基因家族,为铁皮石斛GRF基因功能研究及遗传改良提供理论依据。【方法】通过生物信息学的方法鉴定铁皮石斛14-3-3家族成员,分析其理化性质、染色体定位、系统进化发育、基因结构和启动子顺式作用元件等,同时通过荧光定量PCR技术检测它们在不同组织、低温处理及盐胁迫处理后的表达量。【结果】铁皮石斛有17个GRF家族成员,分为ε类和非ε类亚族,不均匀地分布在7条染色体上,且存在7对串联复制基因。同一亚族成员基因结构、保守基序和蛋白质二级结构相类似。DoGRF家族基因的启动子区域存在大量激素和环境胁迫应答相关的调控元件。DoGRF家族基因在铁皮石斛各组织中均有表达,具有组织表达特异性,大多数基因在花器官中表达最高,其次是茎和根。同时,在低温处理、盐胁迫处理下呈现差异化表达,可能受到低温和盐胁迫的调控,特别是DoGRF2在铁皮石斛逆境应答过程中起着关键的作用。【结论】在全基因组水平从铁皮石斛中鉴定出17个DoGRF家族成员,不同基因对非生物胁迫响应不一,并具有器官表达特异性。DoGRF2对低温和盐胁迫呈现正向响应。

【Objective】14-3-3 protein,also known as general regulatory factor(GRF),encodes through multi-gene family,and plays a central role in encouraging plant growth and development and stress-related adversity responses.The identification of GRF gene family in Dendrobium officinale may provide theoretical basis for the study of D.officinale GRF gene function and genetic improvement.【Method】Bioinformatics was used to identify the members of 14-3-3 gene family,and analyze their physicochemical properties,chromosomal localization,phylogenetic tree,gene structure,and cis-acting elements of each DoGRF member.Simultaneously,their expression profiles in different tissues and under the treatment of low-temperature or salt stress were detected using the real-time quantitative PCR.【Result】Results demonstrated that seventeen DoGRF gene family members were presented in D.officinale,which harbored two subfamilies(εgroup and non-εgroup).They were unevenly located on 7 chromosomes,and harbored seven tandem repeat gene pairs.The gene structure,conserved motifs,and secondary structure of DoGRF members within the same subfamily were similar.The cis-acting elements at the promoter regions of DoGRF family genes contained abundant hormone and stress response elements.DoGRF genes family were expressed in various tissues(flower buds,sepals,labellum(lip),pollinia,gynostemium(column),stems,leaves,roots,green root tips,and white part of roots),and most of them were highly expressed in floral organs,followed by stems and roots.Besides,they were differentially expressed under treatment of low-temperature or saltstress,suggesting that they might be involved in regulating the stresses of low-temperature and salinity.Especially,DoGRF2 might play a crucial role in the process of stress responses.【Conclusion】17 members of DoGRF family were systematically identified from D.officinale at the genome level.Different genes possessed different responses to abiotic stresses,and exhibited tissue-specific expression profiles.DoGRF2 showed positively response to low-temperature and salt stress..