铁皮石斛WD40转录因子家族鉴定及光胁迫下与花青素合成的相关性分析OA

[Objective]In order to clarify the molecular characteristics of the WD40 transcription gene family in Dendrobium officinale and its role in regulating anthocyanin biosynthesis under light stress.[Method]Two Dendrobium officinale cultivars,'Jiuxianhu-5'(red),and'1-8#'(green)were used as experimental materials.Combined with the whole-genome data and transcriptome data under three different light intensity treatments,bioinformatics methods were employed to identify members of the WD40 family.Their phylogenetic evolution,physicochemical properties of proteins,gene structure,cis-acting elements in promoters,and differential expression patterns were analyzed.Key genes associated with anthocyanin synthesis were screened out through correlation analysis.[Result]A total of 129 WD40 gene family members were identified from the Dendrobium officinale genome,which could be clustered into 16 subfamilies with WD40 proteins from Arabidopsis thaliana.Among them,five members in the S5 subfamily were grouped into the same branch as Arabidopsis anthocyanin regulatory gene AtWD40-106(TTG1).The amino acid number of D.officinale WD40 proteins ranged from 192 to 3037,with the molecular weight ranging from 21.73 to 332.44 kDa.Of these proteins,80 were acidic,49 were basic,53 were stable,76 were unstable,127 were hydrophilic,and 2 were hydrophobic,and all were localized in the nucleus.Gene structure and conserved motif analysis revealed that the DcWD40 gene family contained 4 to 15 conserved motifs and 1 to 19 introns,with motif1 being highly conserved.Cis-acting element analysis showed that the promoters of D.officinale WD40 genes contained hormone-responsive,stress-responsive,and light-responsive elements,among which 1,321 light-responsive elements were distributed across 129 DcWD40 genes.Nine genes with different and differential expression genes were screened from the transcriptome data of the three light intensity treatments,among which the expression of DcWD40-105,DcWD40-107 and DcWD40-129 was up-regulated with light enhancement,and was higher than that of green varieties in red varieties.Among the nine differentially expressed genes,DcWD40-105,DcWD40-107 and DcWD40-129 were significantly correlated with anthocyanin components,among which DcWD40-129 had the highest correlation with all anthocyanin components,followed by DcWD40-105 and DcWD40-107.[Conclusion]This study provides theoretical support for analyzing the molecular mechanism of the D.officinale WD40 gene family in response to light and clarifying its regulatory pathway on anthocyanin biosynthesis,and also supplies key candidate genes for the breeding of excellent D.officinale cultivars.