Strigolactone-Mediated Mitigation of Negative Effects of Salinity Stress in Solanum lycopersicum through Reducing the Oxidative Damage

Abstract

Soil salinity is one of the main barriers to increasing global food production as it reduces crop growth and productivity. While irrigated lands in arid climates (about 20% of total affected) are more prone to salinization, many other natural and anthropogenic factors contribute to an increase in salinity in arable lands that currently affects over 100 countries and more than one billion ha. Management of agro-ecosystems at every level, including soil, water, and the plant itself, is important in mitigating the effects of salinity. Plant hormones control cellular metabolism, and mediate plant defense response mechanisms against abiotic and biotic stresses. Foliar fertigation with plant growth regulators has been shown to improve growth and metabolism under stress conditions. Strigolactones (SLs) have emerged as a group of novel phytohormones with several functions in plant interactions with microorganisms, plant metabolism, development, and in responding to many environmental cues. The present research addressed SL (GR24) effects on growth, photosynthetic parameters, and oxidative stress in Solanum lycopersicum under salinity stress. Growth indices, photosynthesis and related attributes, antioxidant enzyme activity, and malondialdehyde (a product of lipid peroxidation) and hydrogen peroxide concentrations were compared in unstressed and salt-stressed (NaCl; 150 mM) S. lycopersicum seedlings untreated or treated with GR24 (2 µM). Improved antioxidant enzyme activity, proline (8%) and protein (14%) contents, and photosynthetic (33%) and transpiration (34%) parameters under GR24 treatment result in a significant increase in plant growth parameters, viz., shoot length (29%), root length (21%), shoot fresh weight (31%), root fresh weight (23%), shoot dry weight (26%), and root dry weight (19%). Increased chlorophyll index (14%) and stomatal conductance (16%) in GR24-applied plants under salinity stress results in improved growth and photosynthetic efficiency of S. lycopersicum. Our results add to the existing knowledge of the relatively new function of SLs in mitigating abiotic stress, particularly that of salinity stress in crop plants.

The Coupling Effects of PGPR Inoculation and Foliar Spraying of Strigolactone in Mitigating the Negative Effect of Salt Stress in Wheat Plants: Insights from Phytochemical, Growth, and Yield Attributes

“…GR24 treatment also affects the activity of PIN1, which influences the flow of the plant hormone auxin and is essential for the formation of lateral roots [69]. Furthermore, Fasial et al [23] demonstrated that GR24 can potentially enhance tomato plant growth, including root fresh and dry weights and the root length under salt stress conditions. crop growth and productivity.…”

“…It has also been reported that using exogenous GR24 in cotton seedlings under salt stress significantly upregulates the genes responsible for antioxidant enzymes, chlorophyll biosynthesis, and the photosynthesis system [22]. Plant growth parameters improved in tomato seedlings treated with GR24 under salt stress, and protein and proline content increased significantly [23].…”

Ascophyllum nodosum (L.) Le Jolis, a Pivotal Biostimulant toward Sustainable Agriculture: A Comprehensive Review

“…AnE improved the expression of diverse miRNAs related to nutrient uptake and enhanced salt stress tolerance in A. thaliana [169]. Bioactive organic compounds of AnE have been reported to regulate the union and communication of different transcription factors such as "DREB/CBF, COR47, NF-YA, COR15A, AGF2, CCA1, and LHY1," which improve stress tolerance in plants [170,171]. Rayirath et al [50] observed that AnE application in A. thaliana stimulated the cold-responsive genes "COR15A, RD29A, and CBF3" and improved the plant's cold stress tolerance.…”

Copper Oxide Nanoparticles Induced Growth and Physio-Biochemical Changes in Maize (Zea mays L.) in Saline Soil

“…Salinity is the most common abiotic stress in arid and semi-arid areas of the world [ 1 ]. Across the globe, 800 million hectares of land are saline [ 2 , 3 ], while in Pakistan, almost 6.8 million hectares are negatively affected by salts [ 4 ]. Salinity adversely affects the morpho-physiological attributes of plants, consequently reducing their yield [ 5 ].…”