Abstract:
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.