Zinc sulfide nanoparticle mediated alterations in growth and anti-oxidant status of Brassica juncea

Studies were carried out to investigate the effect of zinc sulfide nanoparticles on growth and anti-oxidant markers in Brassica juncea. Growth of Brassica júncea seedlings was positively affected by zinc sulfide nanoparticle treatment, with a maximum increase of 49% in shoot dry weight, being recorded at 15 ppm concentration. Increased chlorophyll content and maximal sugar accumulation was also recorded at 15 ppm zinc sulfide nanoparticle treatment. The seedlings treated with 15 ppm and higher concentrations of zinc sulfide nanoparticles recorded increased reduced-glutathione leveis as compared to the untreated seedlings. Higher growth indices of the treated seedlings were associated with improved antioxidant marker leveis, recorded in terms of lower proline accumulation, and reduced hydrogen peroxide & lipid peroxidation leveis. No significant change in total ascorbate content was recorded up to 15 ppm, while a 15% increase was recorded at 100 ppm zinc sulfide nanoparticle treatment. The reduced ascorbate content decreased by just 4.44% at 15 ppm zinc sulfide nanoparticle treatment, while the maximum reduced ascorbate level was recorded at 100 ppm. These observations indicate an alteration in the antioxidant status of the treated seedlings, which is responsible for improved growth profile of the seedlings treated with 15 ppm zinc sulfide nanoparticles, as compared to the seedlings treated with 100 ppm zinc sulfide nanoparticles. The results clearly indicate that zinc sulfide nanoparticles can be used to augment the growth of Brassica júncea seedlings, and this growth stimulatory effect is associated with alterations in antioxidant status of the treated seedlings.