In vitro study of interactive effect of cadmium and salicylic acid on growth and biochemical parameters in tetra and hexaploid wheat

Abstract

In vitro cultures of plants offer a useful tool to study the adaptive mechanisms of plants in the presence of high metal concentrations. Callus cultures of tetraploid (Durum-97) and hexaploid (Shafaq-06) wheat genotypes exposed to different cadmium (Cd) concentrations (0, 100, 400, 800 and 1200 μM) and its alleviation by salicylic acid (0, 0.5 mM) were assayed for growth, antioxidant responses and Cd accumulation characters. Cadmium hampered the growth and notably enhanced antioxidant activity in all Cd regimes. We provided evidence that the two genotypes hexaploid and tetraploid are characterized by different response to cellular homeostasis and detoxification to Cd in callus culture. In particular, the high tolerance in hexploid genotype (Shafaq-06) is associated with relatively higher activity of antioxidants and Cd accumulation behaviour as indicated by Cd contents, bioconcentration factor (BCF) and stress tolerance index (STI). However, the follow-up treatment (0.5 mM) with salicylic acid (SA) mitigated the Cd generated stress and significantly (P≤0.05) improved the aforesaid parameters.