Researchers have found that lowering nitric oxide (NO) levels in plants can significantly enhance nitrogen uptake and Nitrogen Use Efficiency (NUE) in rice and Arabidopsis, offering a promising route for more sustainable and efficient agricultural practices. This discovery paves the way for new strategies to boost crop yields with less nitrogen fertilizer, addressing both food security and environmental sustainability challenges.
Current technologies aimed at improving NUE focus on agronomic practices like split-dose applications of inorganic nitrogen fertilizers, slow-release fertilizers, and others. However, these methods are costly, environmentally harmful, and contribute to the emission of nitrogen oxides (NOx), which exacerbate global warming. The production of inorganic fertilizers also releases significant amounts of greenhouse gases. As such, researchers are looking for more eco-friendly ways to enhance NUE.
A groundbreaking study from the National Institute of Plant Genome Research (NIPGR) reveals that modifying nitric oxide levels at the systemic level can regulate nitrate transporters, particularly high-affinity transporters (HATs), to boost NUE. The research suggests that both genetic and pharmacological manipulation of NO could help increase crop yield, even with lower nitrogen availability.
The study was led by Dr. Jagannath Swain, Dr. Jagadis Gupta Kapuganti, Dr. Nidhi Yadav, and Dr. Sanjib Bal Samant. The team tested their hypothesis by treating wild-type plants with NO donor (SNAP) and NO scavenger (cPTIO), closely monitoring NUE. Overexpressing phytoglobin, a natural NO scavenger, resulted in increased expression of HATs like NRT2.1 and NRT2.4, facilitating better nitrogen uptake—particularly under low NO conditions. NUE was measured by assessing shoot nitrogen levels, amino acid content, and overall plant growth.
This approach represents a significant departure from traditional fertilizer practices, which are not only costly but also detrimental to the environment. By genetically and pharmacologically modulating NO levels, the study offers a sustainable alternative to conventional nitrogen fertilizer methods, promoting better crop performance with reduced nitrogen inputs.
At lower nitrogen levels, plants activate high-affinity nitrate transporters, a process regulated by nitric oxide. Nitrosylation of proteins, triggered by NO, plays a key role in improving NUE. Both genetic and pharmacological strategies to manipulate NO levels have shown promise in enhancing plant growth and nitrogen utilization.
The research was funded by the ANRF (formerly the SERB), an initiative established through an Act of Parliament in 2023.
Dr. Kappuganti emphasized that this study could lead to the development of novel NO scavenging formulations for use in different agroecosystems, offering a new way to reduce the need for nitrogen fertilizers. The team is also exploring the potential of bacteria that could be introduced into soil to act as NO scavengers, further improving NUE in plants.
This promising research offers a sustainable solution to one of agriculture’s most pressing challenges—maximizing crop yields while minimizing environmental impact.
(Source: PIB)
