Transporters regulate silicon uptake to make stripe rust resistant wheat genotypes more effective

Silicon (Si) supplementation is known to aid plants in mitigating various biotic and abiotic stressors. However, the mechanisms underlying Si-mediated stress alleviation, particularly the involvement of Si transporters and genotype-specific responses, remain poorly understood. Against this backdrop, we investigated the role of Si transporters in biotic stress alleviation in specific wheat genotypes infected with stripe rust. The primary objectives were to assess the role of Si accumulation in stripe rust resistance across different wheat genotypes and to determine how Si transporters affect their resistance responses. Twenty wheat genotypes were evaluated for their ability to accumulate Si in shoots, revealing significant variations among the selected genotypes. Resistant genotypes showed higher Si concentrations than susceptible ones, leading to the selection of two contrasting genotypes, viz., WW-120 (resistant) and K-88 (susceptible), for further analysis. In these genotypes, the expression of Si transporters and various physiological and biochemical responses were studied under stripe rust infestation with and without Si supplementation. We found that Si supplementation upregulated the expression of Si transporters, with a more pronounced increase in the resistant genotype than in the susceptible one, resulting in higher Si accumulation in the former. Moreover, differential physiological and biochemical responses to rust infection and Si supplementation were observed in both genotypes, indicating genotype-dependent variations across all measured variables. Our results suggest that higher Si accumulation in resistant wheat genotypes, due to the upregulation of Si transporters, plays a crucial role in their defense against rust infection. Further elucidation of these mechanisms could be used to enhance plant resistance to biotic stressors through targeted Si management.