Unravelling the Synergistic Prospect of Microbial Augmentation in Helianthus annuus-driven Phytoremediation of Cadmium Contaminated Soil

Abstract

Cadmium contamination is one of the alarming threats to the soil as it harms human health by entering the food chain. Cadmium negatively affects the plant by decrease biomass and growth of plants. The addition of bacterial strain has the capability to degrade cadmium in the soil and prevent the cadmium from accumulating in the leaves. Sunflower is an oilseed crop and hyperaccumulator plant because it accumulates the cadmium in its tissues which when eaten enter in human food chain. Hence to remove cadmium from the Helianthus annuus it is important to make it reliable for consumption. Helianthus annuus NARCSUN2020 variety was used. Plants were harvested on the 28th and 56 th day to illustrate the impact of cadmium on the morphological, physiological, the biochemical and gene expression levels. The data was analyzed by the R-studio software by ANOVA and Tukey HSD test. Insilco analysis of Cadmium transporters gene families ZIP, Nramp and HMA genes, sequences identification, domain analysis, conserved motifs phylogenetic analysis and gene structure analysis was done. Statistical analysis revealed that T6 Plant+RS10+ES1) has increased growth and other attributes than other treatments except control. T3 (Plant+RS10+ES1+Cd) effectively reduced cadmium stress as revealed by different parameters studied. PC (Plant+cd) control has reduced growth, reduced biomass and high antioxidants enzyme activity. Three genes were selected from each gene family and their expression analysis was performed using q-RT PCR. HMA2 gene is mostly expressed in roots, Nramp5 gene highly expressed in leaves while ZIP18 gene upregulated in Roots. Soil of control and treated samples were analyzed through X-RD, results showed that PC has cadmium in soil while T3 has not detected the cadmium. We also confirmed through Flame Atomic Absorption spectrophotometry that soil of T3 has the least amount of cadmium(0.056ppm) but in pre sowing soil has 100micromolar(2.727ppm) concentration of cadmium. T3 leaf has no detection of cadmium.