Understanding how carbon is partitioned between oil and carbohydrate storage in oilseed crops is crucial for improving seed composition and meeting the growing global demand for plant derived oil and food. This study explores the sugar-lipid metabolic tradeoff in peanut ( Arachis hypogaea L.) by comparing two varieties with contrasting oil and sugar content: a high oil, low sugar variety (Chengyou1016) with a low oil, sweet variety (Jihuatian1hao) across three seed developmental stages. Transcriptomic analysis revealed a significant transcriptional divergence between the varieties, with the number of differentially expressed genes increasing from 3697 at early stage to 6866 at the maturity stage. Weighted gene coexpression network analysis (WGCNA) identified distinct genetic modules: lipid accumulation was strongly associated to the turquoise and black modules, containing hub genes like WRI1 , DGAT4 , and PDAT1 . In contrast, sugar content was associated with the brown, red, and yellow modules, which were enriched in genes involved in sucrose and raffinose biosynthesis. Lipidomic and sugar profiling confirmed that CY1016 favors carbon flux toward triacylglycerol synthesis, whereas JT prioritizes the accumulation of sucrose and raffinose family oligosaccharides. The qRT-PCR validation further confirmed the stage-specific expression of these hub genes. Our results elucidate a transcriptional framework where WRI1 activation of lipid genes in CY1016 channels sucrose toward oil biosynthesis, whereas sustained sugar pathway activity in JT limits oil production. These findings provide valuable genetic insights into the sugar-lipid partitioning switch in peanuts, offering a foundation for future breeding strategies aimed at optimizing seed composition for nutritional and industrial applications in a resource limited era. • By integrating WGCNA with metabolite profiling, this study reveals how coordinated gene networks determine whether carbon is preferentially allocated to oil or sugar during seed development. • Core regulators such as WRI1, DGAT4, and PDAT1 are shown to drive lipid accumulation, while sugar enriched modules highlight sucrose and raffinose pathway genes that limit oil biosynthesis. • The findings offer actionable genetic targets for developing peanut cultivars optimized for nutritional quality, industrial oil production, and sustainable food systems in a resource conscious era.
Umer et al. (2026) studied this question.