Abstract
Paclobutrazol (PBZ) enhances plant resistance to salt stress in two ways: directly, by straight clearance of reactive oxygen species; and indirectly by enhancing antioxidant enzyme activity, photosynthetic efficiency, and metabolite content, and by regulating transcription factors associated with stress. However, the regulatory effects of PBZ under salt stress in soybean are still not well explained and need further investigation. With this aim, the combination effect of salinity (250 mM NaCl) and three different doses of PBZ (5, 10 and 20 ppm) on physiological, biochemical and molecular traits of soybean (Glycine max L.) leaves were studied in soil experiments. Furthermore, physiological parameters (relative growth rate, relative water content), chlorophyll, malondialdehyde (MDA), hydrogen peroxide (H2O2) content and as well as enzymatic antioxidants (SOD, POX, APX, CAT and GST), ion content (Na, Cl) and soybean Na+/H+ antiporter GmNHX1 and chloride channel GmCLC1 gene expressions were investigated. The results showed that PBZ caused a reduction in salt-induced damages and an increase in biomass yield, water status, and chlorophyll. Moreover, PBZ regulated enzymatic antioxidants and alleviated the oxidative damages under salinity. In this study, for a first time it was determined that PBZ increased both GmNHX1 (ABA dependent or independent) and GmCLC1 (ABA independent) gene expressions and reduced Na and Cl concentrations in soybean under salinity. In conclusion, PBZ plays a role as a regulator and stimulant in salt stress response by mostly regulating ion balance in soybean leaves.
Publisher
Uniwersytet Przyrodniczy w Lublinie
Subject
Horticulture,Plant Science
Reference37 articles.
1. Agha, M.S., Abbas, M.A., Sofy, M.R., Haroun, S.A., Mowafy, A.M. (2021). Dual inoculation of Bradyrhizobium and Enterobacter alleviates the adverse effect of salinity on Glycine max seedling. Not. Bot. Horti Agrobot. Cluj-Napoca, 49(3), 12461–12461. https://doi.org/10.15835/nbha49312461
2. Alexieva, V., Sergiev, I., Mapelli, S., Karanov, E. (2001). The effect of drought and ultraviolet radiation on growth and stress markers in pea and wheat. Plant Cell Environ. 24, 1337–1344. https://doi.org/10.1046/j.1365-3040.2001.00778.x
3. Aly, A.A., Latif, H.H. (2011). Differential effects of paclobutrazol on water stress alleviation through electrolyte leakage, phytohormones, reduced glutathione and lipid peroxidation in some wheat genotypes (Triticum aestivum L.) grown in-vitro. Rom. Biotech. Lett., 6, 6710–6721.
4. Bergmeyer, H.U. (1955). Measurement of catalase activity. Biochem. Z, 327(4), 255.
5. Beauchamp, C., Fridovich, I. (1971). Superoxide dismutase: improved assays and an assay applicable to acrylamide gels. Anal. Biochem., 44, 276–287. https://doi.org/10.1016/0003-2697(71)90370-8