Sweet Potato Gene Clusters Control Anthocyanin Biosynthesis and Leaf Morphology

Area of Science:

• Plant genetics and genomics
• Agricultural science
• Evolutionary biology

Background:

• Sweet potato (Ipomoea batatas) shows diverse pigmentation and leaf shapes.
• The genetic basis for these traits, especially organ-specific control, is not well understood.

Purpose of the Study:

• To investigate the genetic architecture of pigmentation and leaf morphology in sweet potato.
• To identify key genes and regulatory modules controlling these agronomic traits.

Main Methods:

• Genome-wide association studies (GWAS) using 4.6 million SNPs in 260 accessions.
• Integration with transcriptomic, haplotype, and functional analyses.
• CRISPR/Cas9 gene editing for functional validation.

Main Results:

• Two MYB transcription factor clusters on chromosome 5 regulate leaf anthocyanin.
• Distinct genomic regions control storage root pigmentation, involving genes like IbAOMT, Ib3GGT, and IbLDOX.
• A major locus on chromosome 7 controls leaf shape, with genes like BEL1-like, WD40, and LMI1-like playing roles.

Conclusions:

• Clustered gene modules regulate organ-specific traits in sweet potato.
• Evolutionary selection may have driven the expansion of MYB clusters for transcriptional control.
• Identified genetic factors provide insights into phenotypic diversification and trait improvement.