Gene Expression and Secondary Metabolic Regulation Underlying Variegated Leaf Formation in Sweetpotato

Area of Science:

• Plant Molecular Biology
• Plant Biochemistry
• Genomics

Background:

• Variegated sweetpotato leaves are valuable for ornamental and functional food uses.
• The molecular basis of sweetpotato leaf coloration, particularly pink-purple variegation, is not well understood.

Purpose of the Study:

• To investigate the molecular and metabolic mechanisms behind the pink-purple variegated leaf phenotype in sweetpotato.
• To identify microRNA-mRNA regulatory modules involved in leaf color formation.

Main Methods:

• Transcriptome profiling and miRNA sequencing were performed on variegated (Pink) and normal green leaves.
• Differential gene expression analysis, miRNA sequencing, and metabolome analysis were integrated.
• Candidate microRNA-mRNA modules and metabolite accumulation were analyzed.

Main Results:

• 49 differentially expressed miRNAs and 692 regulatory relationships were identified.
• Modules associated with anthocyanin/flavonoid biosynthesis and vacuolar transport were highlighted.
• Flavonoid abundance was significantly higher in Pink leaves, with 28 accumulating over 2-fold.

Conclusions:

• The pink-purple variegated phenotype is primarily driven by the differential accumulation of anthocyanin and flavonol glycosides.
• Specific microRNA-mRNA modules play crucial roles in regulating these pigment biosynthesis pathways.
• Findings provide insights into sweetpotato coloration for breeding and functional food development.