Ramesh Raliya, Jagadish Chandra Tarafdar, Pratim Biswas

Phosphorous (P) is a limiting factor to plant growth and productivity in almost half of the world's arable soil, and its uptake in plants is often constrained due to low solubility in the soil. To avoid repeated and large quantity application of rock phosphate as a P fertilizer and enhance the availability of native P acquisition by the plant root surface, in this study biosynthesized ZnO nanoparticle was used. Zn acts as a cofactor for P-solubilizing enzymes such as phosphatase and phytase and nano ZnO increased their activity between 84 and 108%. Resultant P uptake in mung bean increased by 10.8%. In addition, biosynthesized ZnO also improves plants phenology such as stem height, root volume, biochemical indicators such as leaf protein and chlorophyll contents. In the rhizosphere, increased chlorophyll and root volume attract microbial populations that maintain soil biological health. ICP-MS results exhibited ZnO nanoparticles were distributed in all plant parts including seeds. However, the concentration of Zn was within the limit of the dietary recommendation. To the authors' knowledge, this is the first holistic study focusing on native P mobilization using ZnO nanoparticles in the life cycle of mung bean plants.