Graph-based pan-genome reveals structural variations associated with agronomic traits in mung bean

Area of Science:

• Genomics
• Plant Science
• Agricultural Science

Background:

• Mung bean (Vigna radiata) is a vital legume crop globally, especially in developing nations, due to its rapid growth, nitrogen fixation, and nutritional density.
• Understanding mung bean genetic diversity is essential for improving its agronomic traits and addressing food security challenges.

Purpose of the Study:

• To construct a comprehensive graph-based pan-genome for mung bean (Vigna radiata) using diverse global accessions.
• To identify genetic variants and candidate genes associated with key agronomic traits through genome-wide association studies.
• To elucidate the functional mechanisms of specific genetic variants in regulating important traits like flavonoid content and pest resistance.

Main Methods:

• Assembly of a graph-based pan-genome from 11 genetically diverse mung bean accessions.
• Identification and characterization of gene families and structural variants within the pan-genome.
• Genome-wide association studies (GWAS) integrating structural variants and single nucleotide polymorphisms across multiple environments.
• Functional validation of specific genetic variants in key genes (VrTIFY6B and VrPGIP1).

Main Results:

• The mung bean pan-genome encompasses 75,268 gene families and 66,862 structural variants, providing a rich resource of genetic diversity.
• GWAS identified candidate genes for 20 agronomic traits, highlighting the role of structural variants in mung bean domestication and improvement.
• A promoter insertion in VrTIFY6B was linked to flavonoid content, and a deletion in VrPGIP1 conferred bruchid resistance, demonstrating mechanistic insights.

Conclusions:

• The developed mung bean pan-genome and identified variants offer a powerful toolkit for accelerating crop improvement.
• Actionable functional variants provide targets for marker-assisted breeding, genomic selection, and genome editing.
• These advancements will contribute to enhancing mung bean productivity and resilience, supporting global food security.