Phytohormones Promote the Growth, Pigment Biosynthesis and Productivity of Green Gram [Vigna radiata (L.) R. Wilczek]

Abstract

Globally, optimized doses of exogenously applied growth regulators hold the potential to sustainably boost the growth and productivity of leguminous crops, including green gram. A field investigation was undertaken at the Agronomy Farm of the University of Agriculture Faisalabad, Pakistan in 2021–2022 to determine the highest-performing doses of foliar-applied salicylic acid (S1 = 0 and S2 = 75 ppm) and gibberellic acid (G1 = 0, G2 = 30, G3 = 60, G4 = 90 and G5 = 120 ppm) for green gram (cv. NIAB-MUNG 2011) sown under irrigated conditions in a semiarid climate. The response variables included physiological growth traits (CGR and net assimilation rate (NAR)), yield attributes (plant height (PH), PBs and the number of pods per plant−1 (NP), pod length (PL) and SW, grain (GY) and biological yields (BY), the biosynthesis of pigments (chlorophyll a, chlorophyll b and total chlorophyll along with carotenoids) and protein (P) contents. The results revealed that S2G5 remained unmatched in that it exhibited the highest crop growth rate, while it remained on par with S2G4 and S2G3 in terms of its net assimilation rate. Additionally, S2G5 maximized plant height, the number of pod-bearing branches and pods per plant, pod length, seed number per pod−1 and 1000-seed weight, which led to the highest grain yield and biological yield (104% and 69% greater than those of the control, respectively). Moreover, the same treatment combination also surpassed the rest of the treatments because it recorded the largest amounts of chlorophyll and carotenoid contents, and the P content was increased to 24% greater than that observed for the control treatment. Thus, the exogenous application of salicylic acid (75 ppm) and gibberellic acid (120 ppm) might be recommended to green gram growers to sustainably increase the plant’s yield and nutritional value, and these findings may serve as a baseline for conducting more studies to test higher doses of these growth regulators.

Foliar Application of Moringa Seed Extract Alone or in Combination with Salicylic Acid Enhanced Growth, Bioactive, and Phytohormone Compositions of Cancer Bush Plants under Heat Stress

“…Heat-stressed cancer bush plants treated with MSE and MSE 1 SA showed no symptoms of wilting, which could be attributed to the presence of phytohormones, particularly CKs in MSE (Buthelezi et al 2023;Shakour et al 2023). The presence of CKs in MSE (Buthelezi et al 2022(Buthelezi et al , 2023 prevents premature leaf senescence and maintains higher leaf area for photosynthetic activity and higher chlorophyll concentration in plant leaves (Iqbal et al 2023;Zulfiqar et al 2020). SA treatments enhance synthesis of CKs in plants, which promotes chlorophyll biosynthesis or prevents chlorophyll degradation in leaves (Kaya et al 2023;Kobayashi et al 2020).…”

“…The higher concentrations of ABA, JA, and IAA were observed in heat-stressed cancer bush plants treated with MSE, which could be due to the presence of bioactive compounds and phytohormones in MSE (Buthelezi et al 2022(Buthelezi et al , 2023. Phytohormones promote many plant-related physiological processes and signaling networks in plants to modify plant responses to environmental stressors (Iqbal et al 2023;Singh et al 2023). ABA is synthesized under environmental stress conditions and triggers an adaptive response by activating a group of genes responsible for stress resistance (Iqbal et al 2023;Ma et al 2020).…”

“…Phytohormones promote many plant-related physiological processes and signaling networks in plants to modify plant responses to environmental stressors (Iqbal et al 2023;Singh et al 2023). ABA is synthesized under environmental stress conditions and triggers an adaptive response by activating a group of genes responsible for stress resistance (Iqbal et al 2023;Ma et al 2020). It is involved in the regulation of many aspects of plant performance, including seed germination, embryo maturation, leaf senescence, stomatal aperture, and tolerance to environmental stress (Pal et al 2023;Singh et al 2023).…”

“…It is involved in the regulation of many aspects of plant performance, including seed germination, embryo maturation, leaf senescence, stomatal aperture, and tolerance to environmental stress (Pal et al 2023;Singh et al 2023). JA is a plant-signaling molecule closely associated with plant resistance to abiotic stress and is usually involved in physiological and molecular responses such as the activation of the antioxidant system, accumulation of amino acids and soluble sugars, and regulation of stomatal opening and closing (Hewedy et al 2023;Iqbal et al 2023). IAA regulates growth and developmental processes such as cell division and elongation, tissue differentiation, and apical dominance, and promotes stem and lateral root growth, fruit development, and tolerance to pathogens (Singh et al 2023;Sosnowski et al 2023).…”