Improved salinity tolerance in early growth stage of maize through salicylic acid foliar application

Abstract

Soil salinity threatens agricultural production worldwide by constraining plant growth and final crop yield. The early stages are most sensitive to salinity, in response to which salicylic acid (SA) has demonstrated beneficial effects in various plant species. Based on this, a maize (Zea mays L.) pot experiment was set up combining three levels of soil salinity (0, 6 and 12 dS m–1), obtained through NaCl addition, with three levels of SA (0, 300 and 600 mM), applied by leaf spraying 20 days after seedling emergence. Fifteen days later, the following traits were assessed: morphology (plant height, leaf number), growth (root and shoot dry weight), leaf water status [relative water content (RWC), electrolyte leakage (EL)], pigments (chlorophyll a and b, carotenoids, anthocyanin), antioxidant enzymes (peroxidase, catalase, ascorbate peroxidase, vitamin C), oxidative stress markers (H2O2, malondialdehyde), osmo-regulating compounds (free amino acids, soluble proteins and sugars, proline), hormones [indole-3-acetic acid, gibberellic acid (GA), abscisic acid (ABA), ethylene], element (Na, K, Ca, Mg and Cl) concentration and content in roots, stem and leaves. Salinity severely affected maize growth (–26% total dry weight), impaired leaf water status (–31% RWC), reduced photosynthetic pigments, enhanced all antioxidant enzymes and oxidative stress markers, two osmo-regulating compounds (soluble sugars and proline) out of four, and all hormones except GA. SA was shown effective in containing most of the stress effects, while supporting plant defences by upgrading antioxidant activities (reduced oxidative stress markers), increasing cell membrane stability (–24% EL) and leaf water status (+20% RWC), and reducing plant stress signalling (–10% ABA and -20% ethylene). Above all, SA contrasted the massive entry of noxious ions (Na+ and Cl–), in favour of K+, Ca2+ and Mg2+ accumulation. Lastly, salicylic acid was shown beneficial for maize growth and physiology also under non-saline condition, suggesting a potential use in normal field conditions.
 Highlights - Foliar applied salicylic acid alleviated salinity effects on maize growth at early plant stage. - Salicylic acid improved leaf water status, chlorophyll content, and strengthened anti-oxidant enzymes under salinity. - Salicylic acid reduced oxidative stress markers while enhancing osmo-regulating and hormonal responses to salinity. - Salicylic acid hampered Na and Cl entry and translocation to above ground organs, preserving leaf cell membrane integrity. - Salicylic acid was shown beneficial for maize growth and physiology also under non-saline conditions.

Mitigation of Salinity-Induced Oxidative Damage, Growth, and Yield Reduction in Fine Rice by Sugarcane Press Mud Application

“…Salinity negatively affects crop production and causes huge yield and economic losses; therefore, proper strategies must be adopted to reduce salinity stress on crops and protect the soils from the devastating impacts of salinity stress ( Mohanavelu et al, 2021 ; Monsur et al, 2022 ). Salinity stress is a complex process that negatively affects the plant’s physiological and biochemical processes ( Dustgeer et al, 2021 ; Sultan et al, 2021 ). The effects of salt ranged from seed germination to flowering and fruiting settings, which resultantly caused significant yield losses ( Mbarki et al, 2020 ; El Sabagh et al, 2021 ).…”

“…The effects of salt ranged from seed germination to flowering and fruiting settings, which resultantly caused significant yield losses ( Mbarki et al, 2020 ; El Sabagh et al, 2021 ). Moreover, salt stress also induces osmotic and ionic stress and induce the production of reactive oxygen species (ROS), which cause damages to significant molecules, namely, DNA, proteins, and cellular membranes ( Ahanger et al, 2017 ; Hassan et al, 2019 , 2020 , 2021a ; Mbarki et al, 2020 ; Hossain et al, 2021 ; Sultan et al, 2021 ; Batool et al, 2022 ). Salt stress also reduced the nutrient uptake and enzymes’ activity, therefore significant growth and yield losses ( Kamran et al, 2020 ; Singhal et al, 2021 ).…”

“…Salt stress also reduced the nutrient uptake and enzymes’ activity, therefore significant growth and yield losses ( Kamran et al, 2020 ; Singhal et al, 2021 ). Moreover, salinity stress also reduced the photosynthetic efficiency and increased the accumulation of toxic ions (Na + ), which cause serious growth and yield losses ( Ahanger et al, 2017 ; Mbarki et al, 2020 ; Taha et al, 2020 ; Dustgeer et al, 2021 ; El Sabagh et al, 2021 ; Sultan et al, 2021 ). The adverse effects of salt stress on plants growth and development depend on different factors, namely, planting species, growth stage, environmental conditions, and salts concentration in soil solution ( Aghighi et al, 2018 ; Monsur et al, 2020 ).…”

Exogenously Applied Trehalose Augments Cadmium Stress Tolerance and Yield of Mung Bean (Vigna radiata L.) Grown in Soil and Hydroponic Systems through Reducing Cd Uptake and Enhancing Photosynthetic Efficiency and Antioxidant Defense Systems

“…Moreover, Cd stress negatively affects the mineral uptake, transpiration rate and stomatal conductance [ 12 ]. Cd-induced injury is related to oxidative stress which causes damages to protein, DNA and lipids [ 13 , 14 , 15 , 16 , 17 , 18 ], and eventually leads to plant death [ 10 ]. However, plants respond to that and reduce the damages of heavy metals stress through activating their diverse enzymatic and non-enzymatic anti-oxidants and the accumulation of various osmolytes [ 10 ].…”

Melatonin Induced Cold Tolerance in Plants: Physiological and Molecular Responses

“…Low temperature also induces the production of reactive oxygen species (ROS) ( Hu et al, 2016 ; Dey et al, 2021 ) that damage the proteins, lipids and resultantly inhibit plant growth and, eventually, its productivity ( Hassan et al, 2019 , 2020 , 2021 ). However, plants have an excellent antioxidant system to cope with ROS under stress conditions ( Chattha et al, 2021 ; Dustgeer et al, 2021 ; Imran et al, 2021 ; Seleiman et al, 2021 ; Sultan et al, 2021 ). Additionally, plants can neutralize the impact of cold stress by accumulating various osmolytes such as proline, glycine betaine, soluble sugars, and proteins ( Erdal, 2012 ; Ghosh et al, 2021 ).…”