烟草DGAT基因家族全基因组鉴定与分析

二酰甘油酰基转移酶（DGAT）是三酰甘油合成的关键酶和唯一限速酶。在烟草中鉴定DGAT基因对于研究油脂代谢途径和创造具有附加值的新型油料作物具有重要意义。本研究从烟草基因组鉴定DGAT家族基因，并对序列特性、基因结构、亚细胞定位、进化模式、表达模式等进行分析。结果表明，共获得25个烟草DGAT家族蛋白，其平均氨基酸长度为485，大部分为碱性蛋白和亲水性蛋白，有13个DGAT蛋白定位到8条连锁群上；有16个蛋白定位到内质网，6个定位叶绿体，3个定位到胞外；烟草DGAT蛋白包含典型的WS_DGAT结构域和LPLAT结构域；系统发育树将DGAT家族分为DGAT1、DGAT2、DGAT3和WSD等4个类群，但烟草DGAT仅划分到DGAT2和WSD两个类群；不同烟草DGAT基因的时空表达特性有所差异，并表现出一定的组织特异性，主要集中在衰老叶片和花器官中大量表达。

Genome-wide Identification and Analysis of DGAT Family Genes in Tobacco

Diacylglyceryl transferas(DGAT)is the key enzyme and the only rate-limiting enzyme in the synthesis of triglyceride.Identification of DGAT genes in tobacco is of great significance for creating new oil crops with potentially high value.In this study,we identified DGAT family genes from tobacco genome,and analyzed their sequence characteristics,gene structure,subcellular localization,evolutionary pattern and expression pattern.A total of 25 DGAT family proteins were obtained,with an average length of 485 amino acids,and most of them were basic proteins and hydrophilic proteins.16 proteins located in endoplasmic reticulum,six proteins located in chloroplasts,and 3 proteins located in extracellular space.Tobacco DGAT protein contains typical WS_DGAT domain and LPLAT domain.At genetic level,13 DGAT genes were located to 8 linkage groups.Plant DGAT family genes could be divided into four groups(DGAT1,DGAT2,DGAT3 and WSD)in phylogenetic tree.Tobacco DGAT genes belong to group DGAT2 and group WSD.The temporal and spatial expression of DGAT genes was different in differential tobacco cultivars and showed some tissue specificity,i.e.,mainly expressed in senescent leaves and flower organs.