Exogenous Silicon Application Promotes Tolerance of Legumes and Their N2 Fixing Symbiosis to Salt Stress

How Silicon Alleviates the Effect of Abiotic Stresses During Seed Germination: A Review

“…Previous investigations showed that Si is beneficial to plant abiotic stress tolerance (Debona et al 2017;El Moukhtari et al 2021;Rizwan et al 2015), but the mechanisms of Si action are still unclear. Some authors hypothesized that Si can protect plant by forming a mechanical barrier (Coskun et al 2019).…”

“…Several studies showed the beneficial concentration-dependent effects of various compounds of Si, including CaSiO3, NaSiO3, K2SiO3, and silicon nanoparticles, on seed germination (El Moukhtari et al 2021;Rizwan et al 2015;Siddiqui et al 2020). However, according to Voogt and Sonneveld (2001), silicate salts, like NaSiO3 and K2SiO3, used as sources of Si in growth media, are highly alkaline and if not carefully handled, may cause precipitation issues.…”

“…Si is the second most abundant element after oxygen in the earth's crust. Exogenous application of Si has improved seed germination and embryo viability under various abiotic stresses (El Moukhtari et al 2021;Lamsaadi et al 2022;Rizwan et al 2015;Siddiqui et al 2020). An example of Si improving the seed viability of Medicago sativa L. under salt stress is illustrated in Fig.…”

“…Under drought, salinity, or heavy metal stresses, the addition of Si was found to improve seed germination rates in various plant species by influencing reserve mobilization, membrane integrity, ROS detoxification, antioxidant system, phytohormone metabolism, and gene expression (Ayed et al 2021;Delavar et al 2017;Gou et al 2020;Khan and Gupta 2018). The beneficial effects of exogenous Si on plant tolerance to various abiotic stresses have been the subject of several reviews (El Moukhtari et al 2021;Rizwan et al 2015;Siddiqui et al 2020) covering effects on plant growth, photosynthesis, water nutrition, and productivity of different crops under various abiotic stresses. Here we focus on reviewing the effect of exogenous Si on seed germination under abiotic stresses.…”

Silicon Supply Improves Nodulation and Dinitrogen Fixation and Promotes Growth in Trifolium incarnatum Subjected to a Long-Term Sulfur Deprivation

“…In legumes, the beneficial effects of silicon have also been demonstrated in plants subject to a large panel of abiotic stresses. For example, in several legume species exposed to salt stress, Si supply leads to maintenance of atmospheric N 2 fixation by increasing the number of nodules and their leghemoglobin concentration and nitrogenase activity [ 29 , 30 ]. Although Si has several beneficial effects under a variety of adverse conditions, there are currently no studies that have focused on the effects of Si application to legumes subjected to S-deficiency.…”