Exogenous Melatonin Application Induced Morpho-Physiological and Biochemical Regulations Conferring Salt Tolerance in Ranunculus asiaticus L.

Abstract

This study presents the effects of exogenous melatonin application at different concentrations (50, 100, and 200 μM) on the morphological, physiological, and antioxidant defense systems of the buttercup plant under salinity stress (4.5 and 5.5 ds.m–1 EC). Expectedly, the salinity stress negatively affected the plant growth parameters, cell membrane stability, and POX enzyme activity of R. asiaticus compared to non-stressed plants. However, in a dose-dependent manner, exogenous melatonin foliar application decreased the salt stress-induced symptoms of retarded vegetative growth, physiological characteristics, and oxidative stress level. The results obtained, revealed the significant effectiveness of exogenous melatonin treatment at 200 μM concentration under salt stress conditions by enhancing the plant growth traits such as chlorophyll and carotenoids content, relative water content, proline content, peroxidase enzyme activity (POD), and by the decreased electrolyte leakage rate, and Na+ content, as well as delaying the emergence of flower buds under salinity stress. The salt tolerance index percentages (STI%) for all estimated characters are also calculated for all studied parameters. This study uncovered the beneficial effect of melatonin in reducing salt stress symptoms that can be used to reduce the salinity effect in ranunculus plant production.

Melatonin-Mediated Induction of Salt Tolerance in Maize at Germination and Seedling Stage

“…Likewise, the maximum length of shoot was measured in the treatment with melatonin application @1000 µM (45.00 cm) and the minimum was recorded in control (37.20 cm). (Ahmad et al, 2021;Jiang et al, 2021;Eisa et al 2023;Hussain et al, 2023;Karumannil et al, 2023), which provides a strong support to our data in the present study. Fresh shoot weight (FSW) Fresh shoot weight (Table 2) of SB-9617(7.41 g plant -1 ) produced the highest FSW followed by FH-949 (6.63g plant -1 ).…”

“…Moreover, the potentiality of melatonin for inducing salt tolerance at germination and early seedling stage in different crops, is well established (Castanares and Bouzo, 2019;Jiang et al, 2016;Jiang et al, 2020;Marthandan et al, 2020;Chen et al, 2020;Arun et al, 2022). Li et al (2019) and Eisa et al (2023) reported that an ample quantity of melatonin in the seed may enhance salt tolerance at germination stage by utilizing better nutrient resources and protein formation. Secondly, the exogeneous application of melatonin safeguards the photosynthetic machinery (Chloroplast) and causes significant resumption of the lost activities of the enzymes e.g.…”