Unraveling silicon-induced salinity tolerance mechanism in finger millet (Eleusine coracana) through a transcriptomic approach

Abstract

Finger millet (Eleusine coracana), a nutrient-rich and climate-resilient cereal crop, is widely cultivated in Asia and Africa. Silicon (Si) supplementation has been shown to enhance plant tolerance to abiotic stresses; however, the underlying molecular mechanisms remain unclear. Integrated physiological and transcriptomic analyses were performed to investigate the responses of finger millet seedlings subjected to control, NaCl (200 mM), Si (10 ppm), and NaCl + Si (10 ppm) treatments. Silicon supplementation alleviated salinity stress by reducing membrane damage and enhancing osmolyte accumulation and antioxidant enzyme activities. Transcriptome analysis revealed that Si-mediated salinity tolerance was associated with the upregulation of genes encoding key glycolytic enzymes, including glucose-6-phosphate isomerase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase, enolase, and pyruvate kinase, indicating enhanced carbon flux through glycolysis. Additionally, increased expression of phosphoenolpyruvate carboxylase, malate dehydrogenase, malic enzyme, and RuBisCO indicated enhanced carbon assimilation and coordinated regulation of central carbon metabolism under salt stress. These transcriptional adjustments likely support osmotic balance, energy production, and cellular protection, thereby contributing to improved stress tolerance. The findings provide insights into the molecular basis of silicon-mediated salinity tolerance in finger millet and highlight the potential of silicon-based strategies for enhancing crop resilience in saline conditions.