巨桉脱水素基因EgrDHN家族鉴定及表达模式分析  

Identification and expression pattern analysis of EgrDHN gene family in Eucalyptus grandis

作　　者：苏国芬 李大华 王潘 周料 胡浩 邓海群[3] 陈鑫 冯名开[3] 耿显宸 王翊 徐增富 SU Guofen;LI Dahua;WANG Pan;ZHOU Liao;HU Hao;DENG Haiqun;CHEN Xin;FENG Mingkai;GENG Xianchen;WANG Yi;XU Zengfu(College of Forestry,Guangxi University,Nanning 530004,Guangxi,China;State Forestry and Grassland Administration Key Laboratory of Fast-Growing Timber Breeding in South China,Guangxi University,Nanning 530004,Guangxi,China;State-owned Dongmen Forest Farm,Chongzuo 532108,Guangxi,China)

机构地区：[1]广西大学林学院,广西南宁530004 [2]广西大学中南速生材繁育国家林业和草原局重点实验室,广西南宁530004 [3]广西壮族自治区国有东门林场,广西崇左532108

出　　处：《中南林业科技大学学报》2024年第12期166-177,共12页Journal of Central South University of Forestry & Technology

基　　金：广西重点研发计划揭榜制科技项目(桂科JB22035001);广西科技基地和人才专项(桂科AD23026337)。

摘　　要：【目的】深入挖掘巨桉Eucalyptus grandis脱水素基因EgrDHN家族成员并探讨其应对逆境胁迫的表达模式,从中筛选具有抗逆功能的EgrDHN基因对于培育桉树抗逆新品种具有重要意义。【方法】以巨桉全基因组数据为参考,利用生物信息学筛选鉴定得到巨桉EgrDHN基因家族成员,对其进行生物信息学分析,具体包括进化树分析、蛋白序列比对、启动子序列中顺式作用元件预测等;并基于生物信息学分析结果,采用RT-qPCR测定方法,对EgrDHN基因家族成员在低温、高盐和ABA胁迫处理下的表达模式及其组织表达特异性进行了分析。【结果】从巨桉基因组中共鉴定出EgrDHN家族9个成员,将其命名为EgrDHN1~EgrDHN9,分布于5条染色体上,根据蛋白质保守序列的特点可分为K_(n)S、SK_(n)和Y_(n)SK_(n) 3种类型。系统进化树显示植物DHN家族成员可分为4个进化枝,其中第Ⅳ进化枝包含巨桉EgrDHN7、EgrDHN8、EgrDHN9,但不包含任何毛果杨Populus trichocarpa DHN同源基因(PtrDHNs),两者存在明显差异。启动子元件预测分析发现巨桉EgrDHN启动子中含有低温响应(Low-temperature response,LTR)元件,MYB、MYC等与抗逆性相关以及植物激素响应类顺式作用元件。组织特异性表达分析发现EgrDHN家族成员在根、成熟叶片、子叶中表达量较高,其中EgrDHN2在成熟叶片中表达量最高。非生物逆境胁迫下经RT-qPCR检测发现EgrDHN家族成员中,EgrDHN1在高盐胁迫下表达量下调,在低温和ABA胁迫时上调,而其他成员在低温、高盐、ABA胁迫下均表现为上调,其中低温条件下以EgrDHN2、EgrDHN3、EgrDHN4响应最为明显。【结论】大部分EgrDHNs基因参与逆境胁迫响应,且除EgrDHN1在盐胁迫下的表达量下降外其他成员在逆境胁迫下的表达量均上升。【Objective】It is of great significance to explore the expression patterns of DHN gene family members in E.grandis and to screen the EgrDHN genes with stress resistance function for breeding new varieties of Eucalyptus.【Method】Based on the whole genome data of E.grandis,the EgrDHN gene family members were screened and identified by bioinformatics analysis,including phylogenetic tree analysis,protein sequence alignment,and promoter cis-acting element prediction.【Result】A total of 9 members of the DHN family were identified from the genome of E.grandis and named EgrDHN1-9,which were distributed on five chromosomes.The EgrDHN1-9 were divided into three types of K_(n)S,SK_(n),and Y_(n)SK_(n),based on the conserved characteristics of their sequences.The phylogenetic tree showed that the plant DHN family could be divided into four evolutionary branches,among which the IV evolutionary branch contained EgrDHN7/8/9,but did not contain any P.trichocarpa DHN homologs(PtrDHN),suggesting EgrDHNs and PtrDHN were significantly different from each other.Further analysis revealed that the promoters of EgrDHN mainly contained stress-responsive elements such as low-temperature response(LTR),and the cis-acting elements of stress-resistance related MYB,MYC and phytohormone-responsive genes.Tissue specific expression analysis found EgrDHN family members were highly expressed in roots,mature leaves,and cotyledons,with EgrDHN2 having the highest expression in mature leaves.RT-qPCR analysis revealed that the expression of EgrDHN1 in EgrDHN family members was down-regulated under high salt stress and up-regulated under low temperature and ABA stress,but the expression of other members were up-regulated under low temperature,high salt and ABA stress.Among them,EgrDHN2/3/4 showed the most obvious response at low temperature.【Conclusion】Most of EgrDHN genes are involved in stress response,and all members except EgrDHN1 are down-regulated under salt stress and may play a positive regulatory role.

关 键 词：巨桉 脱水素 非生物胁迫 表达分析 

分 类 号：S718.43[农业科学—林学]