草地早熟禾NAC基因鉴定及非生物胁迫下表达模式分析

Identification of NAC gene family and analysis ofits expression pattern under abiotic stressin Poa pratensis

摘要:

草地早熟禾(Poa pratensis)是世界上广泛应用的草坪草种,其抗逆基因的挖掘对抗逆新品种的选育具有重要意义。NAC基因家族是植物特有的转录因子之一,在植物逆境响应中起到重要作用。以二穗短柄草(Brachypodium distachyon)的NAC蛋白序列为请求序列,从草地早熟禾转录组数据库序列比对分析得到15个草地早熟禾PpNACs基因的cDNA全长序列,具有完整的开放阅读框。运用生物信息学方法预测早熟禾NAC家族成员的理化性质和保守结构域,发现15个PpNACs转录因子都是酸性蛋白,除PpNAC16外都属于不稳定蛋白,疏水性蛋白,具有相似的结构,通过聚类分析可将15个PpNACs成员分为3类。荧光定量PCR结果显示,在重金属胁迫下显著上调表达的基因有PpNAC10、PpNAC18、PpNAC19和PpNAC24,在盐胁迫过程下显著上调表达的基因有PpNAC10和PpNAC24,在干旱胁迫下显著上调表达的基因有PpNAC1、PpNAC6、PpNAC10和PpNAC13,在低温胁迫下显著上调表达的基因有PpNAC1、PpNAC10和PpNAC18,在高温胁迫下显著上调表达的基因有PpNAC20。其中,PpNAC10在重金属、盐、干旱和低温胁迫下均被显著诱导上调表达,PpNAC18在重金属、干旱和低温胁迫下均被显著诱导上调表达,PpNAC10和PpNAC18可作为草地早熟禾逆境胁迫响应的候选基因。

Abstract:

Poa pratensis is a turfgrass species widely used in the world,and the mining of its resistance genes is of great significance to the genetic breeding of new varieties.The NAC gene family is one of plant-specific transcription factors and plays an important role in plant stress response.In this study,the NAC protein sequence of Brachypodium distachyon was used as the request sequence,and the sequence analysis of the P.pratensis transcriptome database obtained 15 full-length cDNA sequences of PpNACs gene of P.pratensis with complete open reading frame.Using bioinformatics methods to predict the physicochemical properties and conserved domains of the NAC gene family of P.pratensis,it was found that the 15 PpNACs genes were all acidic proteins,except PpNAC16,which were unstable and hydrophobic protein,which had similar structure.The 15 PpNACs members could be divided into three categories by cluster analysis.Fluorescence quantitative PCR results showed that the genes that were significantly up-regulated under heavy metal stress were PpNAC10,PpNAC18,PpNAC19 and PpNAC24;the genes that were significantly up-regulated during salt stress were PpNAC10 and PpNAC24;and the genes that were significantly up-regulated under drought stress were PpNAC1 ,PpNAC6,PpNAC10 and PpNAC13;the genes significantly up-regulated under low temperature stress were PpNAC1,PpNAC10 and PpNAC18;and the genes up-regulated under high temperature stress were PpNAC20.Among them,PpNAC10 was significantly up-regulated under heavy metal,salt,drought and low temperature stress,PpNAC18 was significantly up-regulated under heavy metal,drought and low temperature stress.Therefore,PpNAC10 and PpNAC18 could be used as candidate genes of meadow grass in response to abiotic stress.