Unraveling the Dual-Functionality of Chickpea Methyltransferases in Selenium Homeostasis and Stress Resilience

Selenium is vital for plant defence against pathogens and oxidative stress but requires careful regulation to prevent toxicity. This study reveals a new role for dual-function methyltransferases in chickpeas, showing they possess phosphoglycerate kinase (PGK) activity linked to selenium homeostasis, glycolysis, and redox regulation, in addition to their known methylation functions. This finding suggests that methyltransferases contribute to both selenium detoxification and ATP production. Their interaction with PGK connects selenium metabolism to energy production, essential for adapting to oxidative stress. We characterized 32 methyltransferase proteins and found distinct evolutionary differences that separate selenium-related methyltransferases from conventional ones. The presence of PGK-like domains indicates adaptive evolution in selenium-rich environments, enhancing plant resilience. Additionally, we identified regulatory elements and miRNA interactions, emphasizing the importance of methyltransferase-PGK integration in stress resistance. These proteins play crucial roles in selenium detoxification, redox balance, selenoprotein synthesis, and energy regulation, making them key for adapting to stress. Overall, this research enhances our understanding of selenium metabolism in chickpeas and opens pathways for breeding selenium-efficient cultivars with improved stress tolerance.