Abstract
Salinity stress occurs due to the accumulation of high levels of salts in soil, which ultimately leads to the impairment of plant growth and crop loss. Stress tolerance-inducing compounds have a remarkable ability to improve growth and minimize the effects of salinity stress without negatively affecting the environment by controlling the physiological and molecular activities in plants. Two pot experiments were carried out in 2017 and 2018 to study the influence of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) on the physiological and biochemical parameters of sweet pepper plants under saline conditions (2000 and 4000 ppm). The results showed that salt stress led to decreasing the chlorophyll content, relative water content, and fruit yields, whereas electrolyte leakage, malondialdehyde (MDA), proline concentration, reactive oxygen species (ROS), and the activities of antioxidant enzymes increased in salt-stressed plants. The application of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) markedly improved the physiological characteristics and fruit yields of salt-stressed plants compared with untreated stressed plants. A significant reduction in electrolyte leakage, MDA, and ROS was also recorded for all treatments. In conclusion, our results reveal the important role of proline, SA, and yeast extracts in enhancing sweet pepper growth and tolerance to salinity stress via modulation of the physiological parameters and antioxidants machinery. Interestingly, proline proved to be the best treatment.
Highlights
Global food safety is seriously dependent on crops and their supplies, which require considerable increases for servicing the gap between production and demand [1]
Considering the variable effectiveness levels of salicylic acid, proline, and yeast extract on plants, as well as the harmful impact of salinity stress on the growth and productivity of important crops, the present study aims to evaluate and compare the levels of effectiveness of the three stress tolerance inducers, i.e., salicylic acid (1 mM), yeast extract (6 g L−1 ), and proline (10 mM), on the growth characteristics, antioxidants, physiological and biochemical parameters, and yield of sweet pepper plants (Capsicum annuum L.) grown under the same saline conditions in order to determine which stress tolerance inducer should be recommended for further enhancements of crop performance and tolerance
The salt stressed plants treated with salicylic acid, yeast extract, and proline showed significant increases in chlorophyll a and chlorophyll b concentrations compared with stressed untreated plants in both seasons
Summary
Global food safety is seriously dependent on crops and their supplies, which require considerable increases for servicing the gap between production and demand [1]. The necessity of improving crop production has been much more emergent in the last few years due to the expanding population, which will exceed to 9.7 billion by 2050. Increases in the population will exert pressure on crops and food resources [1]. Global warming, as well as various biotic and abiotic stresses, hinder the growth and yields of agricultural crops [2]. Salinity is recognized as one of the main restricting factors affecting the growth and productivity of agricultural crops, especially in arid and semiarid regions [3]. Plants develop cytotoxic-activated oxygen under saline conditions, which might seriously interfere with healthy metabolisms as a result of the oxidative damage of lipids, proteins, and nucleic acids [6,7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
