Metabolomic profiling reveals biochemical dynamics during chickpea seed development and weight determination

This study investigated the complex biochemical changes during chickpea seed development, directly linking them to nutrient accumulation and final seed weight. Researchers comprehensively profiled previously unexplored metabolites in contrasting desi (Himchana, PBG7) and kabuli (L550, JGK1) chickpea cultivars. Samples were collected at key developmental stages: cotyledon, early, mid, and late maturation, just before dry, and almost dried seeds. Non-targeted metabolomics identified 201 metabolites, with desi cultivars showing higher overall accumulation, potentially due to their denser seeds. Metabolite diversity peaked during mid and late maturation (113 and 132 distinct metabolites), aligning with rapid dry matter accumulation and seed weight gain. GC–MS analysis revealed 66 distinct Volatile Organic Compounds (VOCs), predominantly fatty acids. PLS-DA analysis confirmed clear metabolic distinctions across developmental stages and cultivar types, indicating dynamic biochemical remodelling. Himchana and JGK1 exhibited more VOCs than PBG7 and L550. Amino acid and sugar/carbohydrate accumulation was highest in the cotyledon stage, serving as primary building blocks, but decreased later as they converted into storage forms. Secondary metabolites, like terpenoids and flavonoids, peaked during mid and late maturation, suggesting roles in protection and viability. Enrichment analysis highlighted active metabolic pathways, including pantothenate and CoA biosynthesis, various amino acid biosynthesis pathways, carotenoid biosynthesis, and purine metabolism. This in-depth study offers crucial insights into chickpea seed development and weight determination, providing valuable information for breeding programs aimed at enhancing food security. Desi chickpea cultivars consistently show higher and more diverse metabolite accumulation, including amino acids, sugars, and secondary metabolites, compared to Kabuli cultivars, particularly during mid and late maturation stages.