Lead toxicity alters the antioxidant defense machinery and modulate the biomarkers in Tartary buckwheat plants

Abstract

Heavy metal toxicity is a serious global issue as it threatens the future food security by influencing the growth and development of the plant, thereby declining the production yield. Therefore, the aim of the current study was to explore the crops that possess tolerance to heavy metals and investigate their potential as a novel hyperaccumulators, besides provide future food security. Buckwheat is one of potential crop with high nutritional profile compared to cereals and has quickly gained ground in the functional food sector. In the present study, Pb-induced stress in Tartary buckwheat using various physiological and biochemical attributes were investigated. The Pb accumulation was found to be time and dosage-dependent, besides roots were found to accumulate more Pb concentration (21.34 mg/g DM), that in turn declines root and shoot length; besides translocation factor value of <1, indicate sequestration of Pb in the root rhizosphere. Carotenoids and anthocyanin pigment were elevated under Pb-induced stress. The osmolytes (proline, sugar, protein and GSH) and antioxidant defense enzymes (SOD, CAT, APX, POD, GST and GR) enhanced in a time and concentration-dependent manner as also revealed by multivariate analysis. This study suggests that Tartary buckwheat possess an efficient Pb detoxification mechanism as evidenced by enhanced osmolyte production and strong antioxidant enzyme defense system thus could be a novel candidate for cultivation in Pb contaminated soils.