Approaches Involved in the Vegetable Crops Salt Stress Tolerance Improvement: Present Status and Way Ahead

Abstract

Salt stress is one of the most important abiotic stresses as it persists throughout the plant life cycle. The productivity of crops is prominently affected by soil salinization due to faulty agricultural practices, increasing human activities, and natural processes. Approximately 10% of the total land area (950 Mha) and 50% of the total irrigated area (230 Mha) in the world are under salt stress. As a consequence, an annual loss of 12 billion US$ is estimated because of reduction in agriculture production inflicted by salt stress. The severity of salt stress will increase in the upcoming years with the increasing world population, and hence the forced use of poor-quality soil and irrigation water. Unfortunately, majority of the vegetable crops, such as bean, carrot, celery, eggplant, lettuce, muskmelon, okra, pea, pepper, potato, spinach, and tomato, have very low salinity threshold (ECt, which ranged from 1 to 2.5 dS m–1 in saturated soil). These crops used almost every part of the world and lakes’ novel salt tolerance gene within their gene pool. Salt stress severely affects the yield and quality of these crops. To resolve this issue, novel genes governing salt tolerance under extreme salt stress were identified and transferred to the vegetable crops. The vegetable improvement for salt tolerance will require not only the yield influencing trait but also target those characters or traits that directly influence the salt stress to the crop developmental stage. Genetic engineering and grafting is the potential tool which can improve salt tolerance in vegetable crop regardless of species barriers. In the present review, an updated detail of the various physio-biochemical and molecular aspects involved in salt stress have been explored.

Salinity Stress Tolerance in Potato Cultivars: Evidence from Physiological and Biochemical Traits

“…Induction of ROS under stress conditions is correlated with electrolyte leakage and membrane damage [ 58 ]. Our results showed similarity with findings of [ 41 , 59 , 60 ] who reported less reduction in MSI in salt-tolerant genotypes.…”

“…The selected tolerant and sensitive genotypes were re-evaluated in a further study to identify the biochemical, physiological, and ionic mechanisms of salinity tolerance. The better performance of salt-tolerant genotypes under stress conditions was found to be associated with maintenance of high K + /Na + ratio, photosynthetic activity, accumulation of osmotic regulators, and higher activities of antioxidant enzymes that minimize the production of ROS [ 39 , 40 , 41 ]. The results of these studies were found consistent with our experimental findings.…”

Changes in Carotenoid Concentration and Expression of Carotenoid Biosynthesis Genes in Daucus carota Taproots in Response to Increased Salinity

“…Among them, carotenoids are proved to respond to salt stress [30,31]. Carrots are among the vegetable crops that have a very low salinity threshold [32] and are rich in carotenoids, but the specific salt response mechanism is not clear so far. Hence, it is necessary to investigate the dynamic changes and mechanisms of carotenoids under salt stress in carrots.…”

Foliar Application of Salicylic Acid on Growth and Yield Components of Tomato Plant Grown under Salt Stress

“…Saline soils and saline irrigations constitute a serious production problem for vegetable crops as saline conditions are known to suppress plant growth [13].The present study demonstrates salinity adversely affected the growth of tomato cv Marmande regardless of SA treatments. Earlier studies have shown that the concentration of 100 mM NaCl decreased total dry biomass and leaf area [11,14].…”