Deciphering the Role of Plant-Derived Smoke Solution in Ameliorating Saline Stress and Improving Physiological, Biochemical, and Growth Responses of Wheat

Plant-derived smoke (PDS) is an emerging area of interest for research in plant growth during stress conditions. Two wheat varieties (NARC 2011 and NARC 2009) were imbibed in different dilutions of PDS solution and were subjected to salinity (50 mM and 100 mM NaCl). Among all three concentrations (1:100, 1:250, and 1:500), the PDS solution 1:500 has shown improvement in germination, morphological, physiological, and biochemical attributes. It has shown an increase in germination percentage by 48.9% and 27.7% at 50 mM and 100 mM salinity, respectively. Similar results were observed among plant physiological attributes (i.e., relative water content, leaf water potential, leaf osmotic potential, membrane stability index, leaf chlorophyll contents, ionic contents) and biochemical parameters (i.e., proline contents, free amino acid, soluble sugar, protein contents). Among antioxidants enzyme assay, superoxide dismutase activity has shown a reduction of 14.02% and 10.5% at 50 mM and 100 mM NaCl, respectively, by application of PDS solution (1:500 conc.). Compound 1 isolated as a result of repeated column chromatography was light brown and its name [1,4-dihydroxybenzene (hydroquinone)] was confirmed by mass spectrometry. Results have shown that lower concentrations (10 ppm and 25 ppm) exhibited more stimulatory effects on seed germination. In light of our findings, it can be suggested that PDS has shown positive and stimulatory effects on wheat variety NARC 2011 under stress conditions. Moreover, it can be used as an alternative to phytohormones in the coming future.