Silicon Mitigates Salinity Stress by Regulating the Physiology, Antioxidant Enzyme Activities, and Protein Expression inCapsicum annuum‘Bugwang’

Abstract

Silicon- (Si-) induced salinity stress resistance was demonstrated at physiological and proteomic levels in Capsicum annuum for the first time. Seedlings of C. annuum were hydroponically treated with NaCl (50 mM) with or without Si (1.8 mM) for 15 days. The results illustrated that saline conditions significantly reduced plant growth and biomass and photosynthetic parameters and increased the electrolyte leakage potential, lipid peroxidation, and hydrogen peroxide level. However, supplementation of Si allowed the plants to recover from salinity stress by improving their physiology and photosynthesis. During salinity stress, Si prevented oxidative damage by increasing the activities of antioxidant enzymes. Furthermore, Si supplementation recovered the nutrient imbalance that had occurred during salinity stress. Additionally, proteomic analysis by two-dimensional gel electrophoresis (2DE) followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) revealed that Si treatment upregulated the accumulation of proteins involved in several metabolic processes, particularly those associated with nucleotide binding and transferase activity. Moreover, Si modulated the expression of vital proteins involved in ubiquitin-mediated nucleosome pathway and carbohydrate metabolism. Overall, the results illustrate that Si application induced resistance against salinity stress in C. annuum by regulating the physiology, antioxidant metabolism, and protein expression.

Salt stress alleviation by seed priming with silicon in lettuce seedlings: an approach based on enhancing antioxidant responses

“…The increased activity of antioxidant enzymes (Fig. 3a-c) by seed priming with Si may be considered as one of the primary mechanisms against salt stress (Shi et al 2013;Soundararajan et al 2014;Manivannan et al 2016), since that unprimed seedlings to salt exposure exhibited decreased enzyme activities and high MDA content ( Fig. 2a and b, Fig.…”

Silicon-induced Salinity Tolerance Improves Photosynthesis, Leaf Water Status, Membrane Stability, and Growth in Pepper (Capsicum annuum L.)

“…Silicon-influenced levels of enzymes are also involved in sugar synthesis and in starch degradation of sugars (Zhu et al, 2016). Proteomic studies in pepper (Manivannan et al, 2016) and in tomato subjected to salt stress (Muneer et al, 2014) have identified declines in levels of Rubisco and other proteins in the light harvesting complex and such declines were ameliorated by additions of Si solute. In a search for stress markers, Sadder et al (2014) found that Rubisco was associated with salt tolerance.…”

“…From an agronomic viewpoint, application of Si may provide economically relevant productivity improvements for salt-sensitive pepper genotypes grown under moderate salinity conditions and for salt-tolerant genotype grown under higher-salinity conditions. Silicon (Si) is the second-most abundant element in the earth's crust (Manivannan et al, 2016). Its availability to plants is low (Hattori et al, 2005), and the forms of Si (monosilicic and polysilicic acid) are soluble and weakly adsorbed by plants (Matichenkov and Calvert, 2002).…”

The Positive Effect of Different 24-epiBL Pretreatments on Salinity Tolerance in Robinia pseudoacacia L. Seedlings

“…Oxidative factors are prevalent in both lower and higher salinity conditions. For instance, 50 mM NaCl caused a significant reduction in plant growth and photosynthetic parameters accompanied by lipid peroxidation and hydrogen peroxide in Capsicum annuum L. [13]. In addition, 250 mM NaCl and 500 mM NaCl limited the growth of R. pseudoacacia by reducing the antioxidant enzyme activity, combined with a reduction in the photosynthetic pigment contents, damaging the chloroplast ultrastructure [14].…”