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

Abstract

Salt stress is a major problem worldwide because it decreases yields of many important agricultural crops. Silicon is the second-most abundant element in soil and has numerous beneficial effects on plants, particularly in alleviating stress-related impacts. Pepper is an important crop in the Mediterranean region, but pepper varieties differ in their salinity tolerances. The objective of this research was to test the ability of silicon to mitigate effects of salt stress in both salt-sensitive and salt-tolerant cultivars. Salt damage was evaluated by measuring biomass, photosynthetic-related variables, leaf water potential, and membrane damage. We found that the addition of silicon solute to a growth medium was highly effective in improving plant growth by enhancing photosynthesis, stomatal conductance (g S ), leaf water status, and membrane stability, which in turn led to higher biomass production in salt-stressed pepper plants, especially in a salt-sensitive cultivar. 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.

Interactive effects of salinity and silicon application on Solanum lycopersicum growth, physiology and shelf‐life of fruit produced hydroponically

“…and Altuntas et al . who suggested that K content decrease is compensated by the increase in Na content . Similarly, Na + levels were significantly higher when plants were grown in saline conditions which is confirmed by the results of Del Amor et al .…”

“…Plant photosynthetic rate is also negatively affected by high salinity, which could change positively or negatively the protein content, thus affecting quality and inducing several plant secondary metabolism processes and antioxidant mechanisms to resist the impacts of salinity . Several means for the alleviation of negative impacts of salinity have been suggested, including the exogenous application of cations, either through the rooting system or via foliar applications …”

“…Silicon (Si) application has been demonstrated as a promising cultivation practice that can help in alleviating the impacts of salinity at pre‐ and postharvest stage . Several studies have shown that Si is an element that reduces the effect of abiotic stressors including salinity, drought and metal toxicity . This element was also found to improve plant resistance to biotic stress from pathogens, through cell wall reinforcement .…”

“…17,18 Several means for the alleviation of negative impacts of salinity have been suggested, including the exogenous application of cations, either through the rooting system or via foliar applications. [19][20][21][22] Silicon (Si) application has been demonstrated as a promising cultivation practice that can help in alleviating the impacts of salinity at pre-and postharvest stage. 23 Several studies have shown that Si is an element that reduces the effect of abiotic stressors including salinity, drought and metal toxicity.…”

Gas exchange, growth, and quality of passion fruit seedlings cultivated with saline water

“…In relative terms, plants grown under ECw of 3.5 dS m -1 reduced their A by 51.85% (3.80 μmol H 2 O m -2 s -1 ) compared to those subjected to the lowest salinity level (0.3 dS m -1 ). The reduction in CO 2 assimilation rate in plants grown under salt stress occurs due to stomatal closure to reduce water loss, which in turn leads to reductions in leaf transpiration rates and intercellular CO 2 concentration in the leaves (Altuntas, Dasgan, & Akhoundnejad, 2018), promoting a decrease in CO 2 availability for carboxylation (E. N. da Silva, Ribeiro, Ferreira-Silva, Viégas, & Silveira, 2011).…”