Silicon Foliar Application Mitigates Salt Stress in Sweet Pepper Plants by Enhancing Water Status, Photosynthesis, Antioxidant Enzyme Activity and Fruit Yield

Abstract

Silicon is one of the most significant elements in plants under abiotic stress, so we investigated the role of silicon in alleviation of the detrimental effects of salinity at two concentrations (1500 and 3000 ppm sodium chloride) in sweet pepper plants in two seasons (2018 and 2019). Our results indicated that relative water content, concentrations of chlorophyll a and b, nitrogen, phosphorus and potassium contents, number of fruits plant−1, fruit fresh weight plant−1 (g) and fruit yield (ton hectare−1) significantly decreased in salt-stressed sweet pepper plants as compared to control plants. In addition, electrolyte leakage, proline, lipid peroxidation, superoxide (O2−) and hydrogen peroxide (H2O2) levels, soluble sugars, sucrose, and starch content as well as sodium content significantly increased under salinity conditions. Conversely, foliar application of silicon led to improvements in concentrations of chlorophyll a and b and mineral nutrients, water status, and fruit yield of sweet pepper plants. Furthermore, lipid peroxidation, electrolyte leakage, levels of superoxide, and hydrogen peroxide were decreased with silicon treatments.

Chlorophyll Fluorescence Parameters and Antioxidant Defense System Can Display Salt Tolerance of Salt Acclimated Sweet Pepper Plants Treated with Chitosan and Plant Growth Promoting Rhizobacteria

“…The significant increase in these enzymes is a natural defense system, which helps to cope with salinity stress and reduces the osmotic and toxic effects by scavenging ROS. Our results are in agreement with those reported by Abdelaal et al [17] and Foyer et al [93]. Nevertheless, it was clear from our results that the application of seed treatment with B. thuringiensis led to improved and regulated up-regulation of CAT, POX, SOD, and GR in the stressed sweet pepper.…”

“…Glycophytes cannot grow under high salinity concentrations and their response to salinity differs in terms of osmotic regulation, photosynthetic electron transport, chlorophyll content, and reactive oxygen species (ROS) formation as well as antioxidant defense system [1,7]. The excessive accumulation of ROS under stress, such as salinity [1,17], drought [18,19], and biotic stress factors [20][21][22][23], results in the activation of the enzymatic and non-enzymatic antioxidant system to enhance stress tolerance in plants to cope with increased accumulation of ROS [24]. The antioxidative system also consists of some of the non-enzymatic systems, such as salicylic acid and carotenoids.…”

Evaluation of Silicon and Proline Application on the Oxidative Machinery in Drought-Stressed Sugar Beet

“…Sugar beet needs a shorter period of productivity and consumes less water than sugarcane [ 2 , 3 ]. Many environmental stress factors affect the plant growth and productivity in various plants; biotic factors [ 4 , 5 , 6 , 7 ], salinity [ 8 , 9 , 10 , 11 ], heat [ 12 ], drought stress [ 13 , 14 , 15 ]. Drought is one of the most harmful stresses which, threat agricultural production, under drought factor, morphological characteristics such as leaves number, leaf area and stem length were decreased [ 16 , 17 , 18 ].…”

Salinity Stress Enhances the Antioxidant Capacity of Bacillus and Planococcus Species Isolated From Saline Lake Environment

“…Accordingly, several pieces of research have studied the impact of salinity on eukaryotes, particularly plants ( Parida and Das, 2005 ; Ambede et al, 2012 ; Kurum et al, 2013 ; Hussain et al, 2014 ; AbdElgawad et al, 2016 ; Abdelaal K.A. et al, 2020 ; Abdelaal K.A.A. et al, 2020 ; Osman et al, 2020 ), as well as prokaryotes such as cyanobacteria, and their mechanisms of tolerance to high salinity ( Joset et al, 1996 ; Lu et al, 2006 ; Rao et al, 2007 ).…”