Biosynthesized Zinc Oxide Nanoparticles As a Novel Nanofertilizer Influence Growth, Yield, Antioxidant Enzymes, and Arsenic Accumulation in Mungbean (vigna Radiata L.) under Arsenic Stress

To analyze the influence of foliar sprayed zinc oxide nanoparticles (24–28 nm) over a concentration range (0, 10, 20, and 50 mg/L) on two different mungbean cultivars (IPM 02–14 and RMG 975) to ameliorate arsenic toxicity (0, 15, and 30 µM). The zinc oxide nanoparticles (ZnONPs) have been phytosynthesized using Emblica officinalis fruit extract and characterized using various techniques such as UV–VIS Spectrophotometer, zeta sizer and potential, XRD, FTIR, SEM, and EDX. The arsenic and zinc content were determined by atomic absorption spectroscopy. The 30 μM arsenic (As) concentration was highly toxic and led to maximum decrease in growth but supplementation of ZnONPs increased the growth, yield, zinc (Zn) content, activity of antioxidative enzymes, and decreased As accumulation in mungbean cultivars. The supplementation of 20 mg/L ZnONPs decreased the total As content by 45%, 42%, and 39% in IPM 02–14 and 40%, 42%, and 32% in RMG 975 in roots, leaves, and seeds under 30 μM As stress, respectively over the controls. The Zn content in roots, leaves, and seeds of both mungbean cultivars increased linearly with increasing concentration of ZnONPs, indicating that As stress has little or no effect on Zn accumulation. The present study observed that the foliar spray of ZnONPs is effective to ameliorate the arsenic toxicity in mungbean cultivars by increasing the Zn content and decreasing As content in a dose dependent manner. The optimal concentration of ZnONPs was 20 mg/L as it is highly significant to decrease the As content in both the cultivars.