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

Yaser M Hafez,Yasser S A Mazrou,Khaled A A Abdelaal

doi:10.3390/plants9060733

Yaser M Hafez, Yasser S A Mazrou + Show 1 more

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https://doi.org/10.3390/plants9060733

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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.

Highlights

Sweet pepper is one of the most significant vegetable crops, belongs to the Solanaceae family, and has a high importance in the exporting market
We can conclude that salinity stress has a negative impact on sweet pepper plants and this effect can be mitigated by foliar application of silicon
Silicon application led to an increased relative water content, concentrations of chlorophyll, activity of antioxidant enzymes and nutrient uptake as well as number of fruits plant−1, total fruit yield, and fruits fresh weight plant−1

Summary

Introduction

Sweet pepper is one of the most significant vegetable crops, belongs to the Solanaceae family, and has a high importance in the exporting market. Salinity is one of the major restricting abiotic factors for agricultural production worldwide [2], affecting osmotic adjustment and solutes uptake resulting in many harmful changes in morphological and physiological characters such as photosynthetic rate and plasma membrane permeability of many economic plants [3,4,5,6]. Morphological traits such as leaf number and leaf area can be negatively affected under salinity stress [7]. Accumulation of reactive oxygen species (ROS) such as superoxide (O2 − ) and hydrogen peroxide (H2 O2 ) may increase, causing oxidative stress [9] as well as Plants 2020, 9, 733; doi:10.3390/plants9060733 www.mdpi.com/journal/plants

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