The effect of a growth regulator Ribav-Extra on winter wheat seedlings exposed to heavy metals

We studied the influence of a natural plant growth regulator Ribav-Extra and ions of heavy metals (HM) Pb2+, Cu2+, Zn2+ and Ni2+ on the physiological and biochemical indices of the winter wheat (Triticum aestivum L. ) cultivar ‘Mironovskaya 808’. The seeds of wheat were treated with Ribav-Extra (10 ppm) and grown for 7 days on heavy metal salt solutions (10 μM or 1 mM). After that we recorded heavy metals accumulation, growth, generation of superoxide anion (O2), lipid peroxidation (LPO), and catalase (CAT) and ascorbate peroxidase (APOX) activity. It was found that 1 mM of HM in growth media increased heavy metals accumulation in wheat plants and inhibited the growth of roots and shoots. Both low and high concentrations of heavy metals stimulated O2 production and oxidative damage in wheat seedlings. In most treatments, the toxic effect of heavy metals enhanced at higher concentration of metals. Pre-sowing treatment of seeds with Ribav-Extra decreased the negative impact of heavy metals by reducing oxidative stress which led to suppressed O2 generation, lipid peroxidation intensity and catalase activity. This suggests that the wheat plants, whose seeds had been treated with Ribav-Extra, were more heavy metal-resistant than the untreated ones.