烟草抗冷相关基因在两种不同育苗方式下的低温应答差异分析

为探究水旱两段式育苗技术抗低温胁迫的分子机制，利用生物信息学方法分析了烟草低温应答关键转录因子CBF（C-repeat binding factor）基因家族的进化关系、基因结构、保守结构域及其启动子顺式作用元件，进一步利用qRT-PCR分析两种育苗方式下（常规漂浮育苗和水旱两段式育苗）NtCBF基因家族、CBF-regulon基因和非CBF-regulon相关基因的低温应答模式。结果表明，NtCBF15~NtCBF21基因与拟南芥CBF5、CBF6基因进化关系相近，NtCBF1~NtCBF14基因与拟南芥CBF1~CBF4基因进化关系相近。NtCBF基因家族成员均具有motif 1/2/4/5保守蛋白结构域，表明该家族在进化过程中较为保守；其中，NtCBF3、NtCBF4、NtCBF5、NtCBF6、NtCBF10、NtCBF13、NtCBF14和NtCBF18等8个基因启动子区具有低温响应元件。低温处理后，NtCBF5、NtCBF12和NtCBF13及CBF-regulon基因中NtRD29A、NtRD29B和NtGOLS3的表达量均显著升高。推测NtCBF5、NtCBF12和NtCBF13及其下游调控基因NtRD29A、NtRD29B和NtGOLS3在水旱两段式育苗抗低温胁迫过程中起重要作用。 

Differential analysis of low temperature gene responses related to cold resistance in tobacco under two seedling cultivation methods

To explore the molecular mechanism of water-soil two-stage seedling cultivation method against low temperature stress, bioinformatic methods were used to analyze the evolutionary relationship, gene structure, conserved domains and cis-acting elements in promoter of CBF (C-repeat binding factor) gene family in tobacco. Furthermore, qRT-PCR was used to analyze the responsive models of NtCBF gene family, CBF-regulon related genes and non-CBF-regulon related genes to low temperature under two seedling cultivation methods, conventional floating seedling cultivation and water-soil two-stage seedling cultivation. The results showed that the evolutionary relationship between NtCBF15-NtCBF21 gene and CBF5 or CBF6 of Arabidopsis thaliana was close, and that between NtCBF1-NtCBF14 genes and CBF1-CBF4 genes of Arabidopsis thaliana was close. All members of NtCBF gene family had conserved protein domains of motif 1/2/4/5, indicating that the family was relatively conserved during evolution. Among them, promoter regions of eight genes (NtCBF3, NtCBF4, NtCBF5, NtCBF6, NtCBF10, NtCBF13, NtCBF14 and NtCBF18) had low temperature response elements. The expression levels of NtCBF5, NtCBF12 and NtCBF13 of NtCBF gene family and NtRD29A, NtRD29B and NtGOLS3 of the CBF-regulon related genes were significantly increased in water-soil two-stage seedling after the cold treatment. The evidence suggested that NtCBF5, NtCBF12, NtCBF13 and their downstream regulatory genes NtRD29A, NtRD29B and NtGOLS3 might play important roles in the resistance of seedlings cultured by the two-stage method to low temperature stress.