How nanoparticles could help improve plant nutrition

Plants need phosphorus. But they typically can’t process the entire dose of phosphorus-rich fertilizer farmers apply before the nutrient washes away or mineralizes into inconsumable forms. Researchers led by Ramesh Raliya and Pratim Biswas of Washington University in St. Louis have developed a zinc oxide nanoparticle aerosol spray that boosts the ability of mung bean plants to mobilize and better use phosphorus in the soil so less goes to waste (J. Agric. Food Chem. 2016, DOI: 10.1021/acs.jafc.5b05224). The team decided to study mung beans because they are an important source of dietary protein in developing and highly populated areas, especially in Asia. The researchers say the zinc oxide nanoparticles produce similar effects in other crops as well. Plants absorb the nanoparticles through their leaves, and once inside the plant, the zinc accelerates the activity of phosphorus-mobilizing enzymes such as phytase and phosphatase, Raliya and Biswas explain. As a result, plants treated with the nanoparticles take up more phosphorus, produce more chlorophyll, and grow more voluminous roots. The researchers believe this technology will help farmers meet food demand while allowing them to use less fertilizer, which would reduce costs and the environmental impact of agricultural runoff.