Integrated analysis of metabolome and transcriptome reveals the mechanism of divergent acute heat stress responses in mango cultivars

Background Mango ( Mangifera indica L.) growth is affected by temperature, and heat stress often occurs in southern China, leading to a sharp decline in mango quality and yield. Understanding the response mechanism of mangoes and conducting research on their acute heat stress response and genetic breeding are urgently needed. Results and discussion Heat stress induces multiple physiological impairments in mango seedlings through oxidative stress. Metabolome analysis identified 12 major metabolite classes, with amino acids and derivatives (AADs), phenolic acids (PAs), flavonoids (FLs), and lignans and coumarins (Lc) being the most responsive to acute heat stress, which provides a solid basis for subsequent research. RNA-seq analysis revealed that 12,635 differentially expressed genes (DEGs) were related to photosynthesis, homeostasis regulation, stomatal regulation, and other key plant hormone pathways. Weighted gene co-expression network analysis identified that copper chaperone, cytochrome c, and 5’-AMP-activated protein kinase (AMPK) were the key genes involved in acute heat stress response. Integrated Pearson correlation analysis across 36 samples revealed a strong, statistically significant gene–metabolite network (|r| > 0.7, p < 0.001), with AMPK showing the most extensive associations to lipids, flavonoids, and amino acid derivatives. These findings provide a unique theoretical basis for studying early heat-stress response mechanisms and for genetic breeding of mango, and offer valuable information for breeding heat−tolerant mango varieties.