Mechanistic Basis of Silicon Mediated Cold Stress Tolerance in Alfalfa (Medicago sativa L.)

Abstract

Cold stress (CS) impact on crops is one of the critical constraints for sustainable and smart agricultural production. CS adversely affects plants leading to growth retardation, necrosis, chlorosis, and significant yield loss. The objective of this study was to explore the mechanistic basis of silicon (Si) in enhancing CS tolerance in alfalfa plants. The fluorescence staining indicated that Si-reduced the intensity of CS-induced superoxide radical (O2•–) and hydrogen peroxide (H2O2) generation in plants that improved plant photosynthesis, cellular integrity, and alfalfa biomass production under CS. The exogenous supplementation of Si significantly restored the endogenous Si status accompanied by the upregulation of NIP (nodulin 26-like intrinsic protein) genes NIP2, NIP5;1, and NIP6;1 in alfalfa. The elemental concentration analysis revealed that exogenous silicon (E-Si) triggers the increase of calcium (Ca), magnesium (Mg), and sulfur (S) in plants subjected to Si-supplementation compared to the plants cultivated without Si under CS. The application of Si significantly increased the activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR). Furthermore, Si significantly enhanced the expression of CS-responsive candidate genes including ICE1, CBF1/DREB1C, CBF2/DREB1B, CBF3/DREB1A, COR15A, COR47, and KIN1 in alfalfa. These findings together provide mechanistic insights into Si-involving CS tolerance in alfalfa. This eco-friendly SC management strategy using Si treatment can be useful to plant breeders and farmers for developing CS-resilient smart alfalfa production through breeding program.

Effects of exogenous glycine betaine on growth and development of tomato seedlings under cold stress

“…Cold stress is a significant environmental factor that has a detrimental impact on plant growth and productivity (Liu et al, 2012;Réet al, 2017). When exposed to low temperature, plants undergo physiological and biochemical responses, including the production of reactive oxygen species (ROS), inhibiting photosynthesis and changes in osmotic solutes (Lu et al, 2020;Rahman et al, 2023;Xu et al, 2023). In order to survive under cold stress, plant activates cold response signals and transduction to regulatory networks which initiates multiple responses, including physiological and biochemical responses (Ding et al, 2020).…”