Asian Basic and Applied Research Journal

The present study was conducted to know the effect and mechanisms of melatonin priming on seedlings establishment of two wheat cultivars under salt stress. The data obtained on various seedlings parameters measured under study were analyzed statistically by using SPSS (SPSS Inc, Chicago, IL). Significantly different means of the measured data were separated at the 0.05 probability level by the Duncan’s Multiple Ranges Test. The study was conducted at the department of Laboratory, China, during the growing season 2020-2021. Seeds of two cultivars of winter wheat (Triticum aestivum L. cv Argine and Buahin) were separately primed with 500 μM of melatonin before germination for 20 h and after germinated at three- leaf-stage consequently exposed to 300 mM NaCl salt stress. The results revealed that salt stress caused marked reduction in seedling growth attributes and shoot and root water content (RWC), leaf area, and chlorophyll content, while melatonin priming alleviated these reductions. Furthermore, salt stress caused decrease of photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (Tr), where melatonin priming improved these traits. The actual photosynthetic efficiency (ÖPSII), maximum photochemical efficiency (Fv/Fm), photochemical quenching (qP) in the stressed seedlings were inhibited, while non-photochemical quenching (NPQ) was increased, whereas melatonin priming seems to enhance these reductions. We also found that, salt- stressed plants had lower contents of total soluble sugar, sucrose, but were higher in proline content, whereas seeds primed with melatonin improved the total soluble sugar and sucrose. Also exogenous melatonin pretreatment mitigated the salt induced inhibition of (IAA) content. In conclusion the results of the study provide a novel use of melatonin in wheat during seedling establishment under salt stress. We expect that the positive effect of melatonin in alleviation salt stress present new opportunities for its employ in agriculture.