Strigolactone-mediated amelioration of salinity stress in bread wheat: Insights from phytochemical and ion channels related genes expression analyses

Abstract

Foliar application of growth regulators seems to alleviate the adverse effects of abiotic stresses in plants through different mechanisms such as antioxidative and gene expression regulation. As an important abiotic stress, salinity has an enormous negative impact on crop plants such as bread wheat. In the present study, exogenous strigolactone (GR24) was considered for its potential stress-mitigating effect in two contrasting wheats cultivars (‘Arta’ and ‘Karchia’) grown under 2,053,100 mM NaCl stress (10 dS m−1). Yield-related traits, oxidative (APX, POX, CAT, H2O2, MDA, GB and Proline), ionic indices (Na+ and K+ content in leaf and root), and the expression of a selected set of oxidative stress related genes (TaAPX, TaGPX, TaP5CS, TaNHX2, TaSOS1, TaHAK, TaAKT2 and TaHKT2;1) were surveyed in the flowering stage. Strigolactone application (10 μM) had a significant effect on the induction and improvement of biochemical and ionic features such as reducing the electrolyte leakage, H2O2 and MDA or increasing the grain yield, total protein, proline, GB and antioxidant enzymes (APX, POX) activity, of salinity-stressed plants. The gene expression analysis with real-time PCR showed transcriptional variation of selected genes in response to salt stress and GR24. Improved homeostasis in Na+ and K+ and their ratio was found to be correlated with the expression of the antiporter genes and the consequent reduction of ion toxicity. The findings of this study can improve our knowledge about complex mechanism of strigolactone plant hormone during salt stress in crop plans to mitigation of salinity stress.