Influence of foliarly applied different triazole compounds on growth, nutrition, and antioxidant enzyme activities in tomato (Solanum lycopersicum L.) Under salt stress

Abstract

A pot experiment was conducted to investigate the effects of five different triazole compounds, triadimenol, tebuconazole, bitertanol, triadimefon, and paclobutrazol on the growth, macro-nutrition, antioxidative enzyme activities and other stress related parameters in Solanum lycopersicum L. (tomato) plants grown in greenhouse conditions under salt stress. Plants were treated with 30 mg L-1 triadimenol, 250 mg L-1 tebuconazole, 250 mg L-1 bitertanol, 40 mg L-1 triadimefon, and 40 mg L-1 paclobutrazol in separate treatments using foliar spray. NaCl treatment at 125 mM decreased overall growth and fruit yield; reduced chlorophyll, carotenoid, and relative water content; but increased proline accumulation, superoxide dismutase, peroxidase and polyphenol oxidase enzyme activities, soluble protein content, and electrolyte leakage. In addition, NaCl stress resulted in high accumulation of Na+ and decreased the contents of Ca2+, K+, and P in the leaf and roots. With different triazoles, compound treatments overcame, to different extents, the adverse effects of NaCl stress on the above physiological and biochemical parameters. Triazole compounds treatment significantly enhanced the fresh and dry weight of shoots and roots as well as macro element contents of plant organs. Among the treatments, TRI, TEB, and TDM improved these parameters to a greater extent compared to other compounds. NaCl treatments remarkably increased the antioxidative enzyme activities at 5% probability level when compared to control plants. In addition, exogenous application of different triazole compounds promoted this status. Triazol treatment increased the total chlorophyll, carotenoid, and relative water contents to a greater extent compared to salt-stressed plants. Compared to other triazoles, TDM and TEB treatments increased the above-mentioned parameters to a greater extent. Thus, the results of the present study indicate that the application of different triazole compounds reduced the detrimental effects of salinity and increased resistance to salinity in tomato plant.