Interactive effect of 24-epibrassinolide and silicon alleviates cadmium stress via the modulation of antioxidant defense and glyoxalase systems and macronutrient content in Pisum sativum L. seedlings

Abstract

BackgroundThis study assessed the effects of 24-epibrassinolide (EBL, 10–7M) and silicon (2 mM) on the alleviation of cadmium (Cd, 150 mg L–1) toxicity in Pisum sativum L. seedlings via the modulation of growth, antioxidant defense, glyoxalase system, and nutrient uptake.ResultsShoot and root lengths declined by 46.43% and 52.78%, respectively, following Cd stress. Shoot and root dry weights also declined with Cd toxicity. Biochemical and physiological aspects exhibit significant decline including total chlorophyll (33.09%), carotenoid (51.51%), photosynthetic efficiency (32.60%), photochemical quenching (19.04%), leaf relative water content (40.18%), and gas exchange parameters (80.65%). However, EBL or Si supplementation alone or in combination modulates the previously mentioned parameters. Cadmium stress increased proline and glycine betaine (GB) contents by 4.37 and 2.41-fold, respectively. Exposure of plants to Cd stress increased the accumulation of H2O2, malondialdehyde content, electrolyte leakage, and methylglyoxal, which declined significantly with EBL and Si supplementation, both individually and in combination. Similarly, Cd stress adversely affected enzymatic and non-enzymatic antioxidants, but EBL and/or Si supplementation maintained antioxidant levels. Glyoxalase I (GlyI) accumulated after Cd stress and increased further with the application of EBL and Si. However, GlyII content declined after Cd stress but increased with supplementation of EBL and Si. Cadmium accumulation occurred in the following order: roots > shoots>leaves. Supplementation with EBL and Si, individually and in combination reduced Cd accumulation and enhanced the uptake of macronutrients and micronutrients in shoots and roots, which declined with Cd toxicity.ConclusionThe application of 24-EBL and Si, individually and in combination, alleviated the adverse effects of Cd by improving growth, biochemical parameters, nutrient uptake, osmolyte accumulation, and the anti-oxidative defense and glyoxalase systems in Pisum sativum seedlings.

Modulation of Cadmium Tolerance in Rice: Insight into Vanillic Acid-Induced Upregulation of Antioxidant Defense and Glyoxalase Systems

“…The inclusion of VA in the growth medium increased both the Gly I and Gly II enzyme activity, thus reducing the MG content and providing the seedlings with tolerance against MG-induced glycation as well as oxidative stress. The results of the present study are corroborated by those of other researchers who reported phytoprotectant-induced increases in the Gly enzyme activity and concomitant reduction in MG content [41,42].…”

Influence of Exogenous Salicylic Acid and Nitric Oxide on Growth, Photosynthesis, and Ascorbate-Glutathione Cycle in Salt Stressed Vigna angularis

“…Sheng et al [65] have demonstrated increased uptake of K and Ca due to SA in wheat, resulting in the up-regulation of antioxidant system and mitigation of oxidative effects under manganese stress. Increased uptake of mineral nutrients influences the cellular functioning and whole plant performance by regulating processes like photosynthesis, antioxidant systems, and enzyme activity [42,66]. In salt-stressed cucumber, foliar application of SA has been reported to mitigate the reduction in uptake of key macro and microelements.…”

Silicon Confers Soybean Resistance to Salinity Stress Through Regulation of Reactive Oxygen and Reactive Nitrogen Species

“…Plants grown under salinity stress show common symptoms or physiological responses due to the accumulation of toxic levels of ions (Na + , Cl − , and SO 2 − ) in the cells, leading to nutritional and osmotic imbalances, and water use insufficiency (Hasegawa et al, 2000;Kim et al, 2014a;Shu et al, 2017;Rehman et al, 2019). Moreover, reactive oxygen species (ROS), such as the superoxide anion (•O 2 − ), hydroxyl radicals (•OH − ), and hydrogen peroxide (H 2 O 2 ), accumulate in salt-stressed plants (Kim et al, 2014a;You and Chan, 2015;Jan et al, 2018;Ahmad et al, 2019). Ultimately, the plant cell walls collapse, causing the plant cells to die (Shu et al, 2017;Rehman et al, 2019).…”