Bacterial inoculation remediates heavy metals toxicity through modulating biochemicals and antioxidant enzymes of Daucus carota L. grown in lead contaminated soil

Abstract

Due to streamlined industrialization, soil contamination has become major cause of scaling down of the crop productivity. In the course of current study, the negative effects of lead (Pb) contaminated soil on growth, physiology, antioxidative enzymes and yield of selected genotypes of carrot (Daucus carota L.) were studied. The conclusions drawn from the conducted research depicts that all growth contributing factors were divulges to be decreased under the influence of standardized treatment of lead (Pb). Pb toxicity also reduced yield contributing factors of carrots i.e. root length, diameter and weight. Bio-inoculants improved yield of carrots not only in control but also under Pb stressed conditions. Total soluble sugars and reducing sugars were also reduced by Pb toxicity; while bio-inoculants treatment tends to lower the negative effects of Pb toxicity. The level of enzymes phenylalanine ammonia lyase, polyphenol oxidase and peroxidase increased significantly in response to Pb toxicity. Bio-inoculants reduced the accumulation of these enzymes hence indicating amelioration of Pb toxicity. Application of bio-inoculants played a pivotal role to ameliorate lead (Pb) toxicity, thus, can be potentially used to eradicate Pb stress in contaminated sites. The selected 29 genotypes are categorized into three groups, highly tolerant, moderately tolerant and susceptible.