Evaluation of silicon-facilitated growth performances and regulation of Na+ and K+ homeostasis in salt-stressed wheat varieties

Silicon (Si) supplementation is currently gaining popularity in the field of salt tolerance in a variety of crop plants. Si in plants substantially diminishes the negative effects of salinity and can boost wheat's ability to withstand stress. However, the effect of Si on different wheat varieties and how they respond to Si under severe stress conditions are still unknown. In this investigation, we demonstrated the effect of Si on the growth attributes like germination percent, radicle length, seed vigor index, shoot-root length, plant biomass, biochemical parameters like sodium and potassium ions, and K+/Na+ ratio of two wheat varieties, i.e., KRL-210 (salt-tolerant) and WH-1105 (salt-sensitive) under different saline conditions (40, 80, and 120 mM), both with and without Si treatments. Higher levels of salinity reduced the growth performance of both wheat varieties. It was observed that the increase in sodium ion content during salinity decreased the overall growth of the plants. Potassium content was also found to decrease under increased concentrations of salt. Consequently, the K+/Na+ ratio of roots, shoots, and leaves was also dramatically decreased under salt stress. The WH-1105 variety was found to be badly affected during high salt stress, as KRL-210 is more salt-tolerant than WH-1105, while Si supplementation amended the growth attributes of both varieties under severe salt stress. Moreover, Si supplementation enhanced the potassium content and reduced the sodium uptake in plants under stress situations. The positive effect of Si was found more remarkable in the WH-1105 variety than in KRL-210, showing Si's species-dependent nature. The outcome of this research may aid in the development of alternative approaches for defending wheat plants from severe salinity, as well as providing a scientific base for the assessment of salt tolerance and the systematic agriculture of wheat.