Interactive effect of potassium and spermidine protects growth, photosynthesis and chlorophyll biosynthesis in Vigna angularis from salinity induced damage by up-regulating the tolerance mechanisms

Abstract

Pot experiments were conducted to evaluate the role of potassium (100 mg KCl / kg soil) and the spermidine (100 µM Spd) in regulation of growth, chlorophyll synthesis and photosynthesis in Vigna angularis under salinity stress (100 mM NaCl). Salinity declined chlorophyll synthesis by causing a significant decline in the synthesis of δ-amino levulinic acid (ALA), prototoporphyrin IX (Proto IX) and Mg-prototoporphyrin IX (Mg-Proto IX), however application of K and Spd alone as well as combinedly alleviated the decline to considerable extent. Further, K and Spd treated plants exhibited a significant decline in reactive oxygen species and the lipid peroxidation and such effects were also obvious under salinity stress. Photosynthetic rate, stomatal conductance, intercellular CO2 concentration, Fv/Fm and photochemical quenching increased significantly due to K and Spd application, and salinity induced alleviation of the decline was maximal due to combined K and Spd treatment. Up-regulation of antioxidant enzymes activity, increased content of ascorbic acid and glutathione (GSH), and the accumulation of compatible osmolytes due to K and Spd application strengthened the tolerance against the salinity stress thereby lessening the oxidative effects considerably. Accumulation of phenols and flavonoids increased significantly due to application of K and Spd. Salinity caused significant increase in Na however K and Spd application induced a significant decline concomitant with increase in K content reflecting in decreased Na/K. Results suggest that K and Spd application protect the growth and photosynthesis from salinity induced oxidative damage by up-regulating the ion homeostasis, antioxidant system, osmolyte accumulation and secondary metabolite synthesis.

Supplementation of nitric oxide and spermidine alleviates the nickel stress-induced damage to growth, chlorophyll metabolism, and photosynthesis by upregulating ascorbate–glutathione and glyoxalase cycle functioning in tomato

“…Carotenoids act as accessory light-harvesting pigments and protect the photosynthetic apparatus from the toxic effects of radicals, act as redox intermediates in the secondary pathway of electron transfer with PSII, and bring about the stabilization of pigment–protein complexes ( Frank and Brudvig, 2004 ; Hashimoto et al., 2016 ; Zulfiqar et al., 2021 ). Recently, Al-Mushhin (2022) has demonstrated significant alleviation in the salinity-induced decrease in δ-ALA, Proto IX, Mg-Proto IX, chlorophyll, and photosynthesis with Spd application. The combined application of NO and Spd maximally enhanced the chlorophyll and carotenoid synthesis and the stomatal and non-stomatal attributes of photosynthesis under normal conditions and Ni treatment.…”

Exogenously Supplemented Proline and Phenylalanine Improve Growth, Productivity, and Oil Composition of Salted Moringa by Up-Regulating Osmoprotectants and Stimulating Antioxidant Machinery

“…Salinity stress stimulated chlorophyllase degraded enzymes and lowered nitrogen uptake, resulting in a reduction in chlorophyll content, photosynthetic rate, and depressed plant health and productivity [45,46]. Salt stress has been reported as a limiting factor for the growth and biomass yield of tomato [47], cotton [48], sugar beet [49], sweet pea [8], and bean [50] plants. In contrast, Pro and Phe treatments enhanced the plant growth and development of moringa trees under both saline and non-saline conditions.…”