基于油橄榄全基因组参与水胁迫NAC基因的鉴定及表达分析

Identification and Expression Analysis of NAC Gene Involved in Water Stress Based on the Whole Genome of Olea europaea

本研究以干旱和水淹胁迫中的‘佛奥’和‘TYZ-1号’2个油橄榄品种苗木为试材,基于油橄榄全基因组数据,鉴定出36个油橄榄NAC转录因子家族成员,利用生物信息学软件进行结构及功能预测,将油橄榄OeNAC蛋白与模式植物拟南芥AtNAC蛋白构建进化树。结果表明OeNAC转录因子分为两个大类和14个亚家族,14个亚家族中有13个亚族同时包含了油橄榄和拟南芥NAC蛋白,说明拟南芥和油橄榄的NAC家族在进化水平上有一定的相似性。结合油橄榄水分胁迫(干旱,水淹)基因表达谱,分析出8个NAC转录因子(OeNAC31,OeNAC33,Oe NAC25,Oe NAC30,OeNAC7,OeNAC23,OeNAC20,OeNAC1)在‘佛奥’和‘TYZ-1号’中均呈现高表达且对水分胁迫均有响应,推测这8个基因是油橄榄水分调节的主要基因。将在水分胁迫下具有表达量的Oe NAC蛋白与已知水分胁迫相关的NAC转录因子构建进化树发现8个胁迫相关的转录因子中的Oe NAC31与已知的水分调控因子支持率更高,表明OeNAC31转录因子可能是参与油橄榄水分调控的最主要基因,其在两个品种中都有不同的表达量,这可能是‘佛奥’和‘TYZ-1号’抗性不同的原因。本研究通过油橄榄转录组测序,对油橄榄NAC转录因子进行全基因组鉴定、蛋白理化性质、系统发育、保守元件及基因表达谱分析,探究油橄榄NAC转录因子在‘TYZ-1号’和‘佛奥’中基因表达模式,也为油橄榄NAC基因家族的功能验证及水胁迫反应关键基因的挖掘提供参考。

In this study,seedlings of’Frantoio’and’TYZ-1’Olea europaea varieties were used as experimental materials under drought stress and water flooding stress.Based on the whole genome data of Olea europaea,36members of NAC gene family were identified.Using bioinformatics software to predict the structure and function;Olea europaea Oe NAC protein and model plant Arabidopsis AtNAC protein were used to construct the evolutionary tree.The results showed that the Oe NAC transcription factors could be divided into two major groups and 14subfamilies,of which 13 subfamilies contained the NAC proteins of Olea europaea and Arabidopsis thaliana,suggesting that the NAC families of Arabidopsis thaliana and Olea europaea had some similarities at the evolutionary level.By analyzing the gene expression profile of Olea europaea(under drought and water flooding conditions),it was found that 8 NAC transcription factors(OeNAC31,OeNAC33,OeNAC25,OeNAC30,OeNAC7,OeNAC23,OeNAC20,OeNAC1)were highly expressed in both varieties and were highly responsive to water stress.It was speculated that these 8 genes might be the main genes of water regulation in Olea europaea.The phylogenetic tree was constructed between Oe NAC protein with expression under water stress and known NAC transcription factors related to water stress.It was found that OeNAC31 had the highest support rate with known water regulatory factors,indicating that Oe NAC31 transcription factor may be the main gene involved in water regulation of olive.Moreover,there were different expression levels of OeNAC31 in both cultivars,which might be the reason for the different resistance between’Frantoio’and’TYZ-1’.In this study,the whole genome of the Olea europaea NAC transcription factors was identified by transcriptome sequencing,and the physicochemical properties,phylogeny,conserved elements and gene expression profiles of the proteins were analyzed to explore the expression patterns of the Olea europaea NAC transcription factors in’TYZ-1’and’Frantoio’.It also provides reference for functional verification of NAC gene family in Olea europaea and mining of key genes in water stress response.