Reducing fertilizer consumption while ensuring plants have adequate nitrogen uptake is a problem that researchers are attempting to crack. The National Institute of Plant Genome Research (NIPGR) in New Delhi has now developed a way of improving ‘nitrogen use efficiency’ (NUE) by merely reducing nitric oxide content in plants (mainly rice). 

Current NUE pathways focus on agronomic practices such as the application of inorganic nitrogen fertilizers in split doses and slow release of the fertilizer. These come with their share of pitfalls — additional operational costs to farmers and higher emission of nitrogen oxides. 

The researchers at NIPGR have developed a simple alternative to agronomic pathways. The team — comprising Dr Jagannath Swain, Dr Jagadis Gupta Kapuganti, Dr Nidhi Yadav and Dr Sanjib Bal Samant — adopted a “pharmaceutical approach”. Using genetic engineering, they got the experimental plants to produce more phytoglobin, a molecule that captures and destroys nitric acid (NO). For this reason, phytoglobin is called the ‘NO scavenger’. When nitric acid levels fall, it triggers a chain reaction. Plants produce more ‘nitrate transporters’ — specialised proteins found in the membranes of cells in roots. Nitrate transporters absorb nitrate, a form of nitrogen present in the soil, and move it up into the plant. Plants use nitrate to produce molecules such as amino acids and proteins, which are needed for their growth. 

Unknown pathway

By “overexpressing” phytoglobin, the plants in the study produced more ‘high-affinity nitrate transporters’ (HATs), which sucked up more nitrogen from plants. On a field, this method can help reduce the application of fertilizers. “This innovative approach diverges from traditional, costly, and environmentally harmful fertilizers. Instead, it genetically and pharmacologically modulates NO levels to regulate HATs, offering a sustainable solution to boost crop yield with reduced nitrogen inputs,” says a press release from the Department of Science and Technology. 

This research is shining a light on a hitherto unknown pathway for NUE. More research in this direction can lead to better results. Dr Kapuganti points out that the current study offers a promising pathway to develop novel NO scavenging formulations for different agroecosystems to improve NUE and reduce the need for nitrogen fertilizers. Now the team is trying to identify bacteria which, when introduced in the soil, can act as NO scavengers in the plants, leading to improved NUE.

Source:thehindubusinessline