Research Reveals New Approach to Improve Nitrogen Use, Enhance Yield, and Promote Flowering in Rice

Nitrogen fertilizer helps increase crop yields, but excessive use causes environmental pollution. Large amounts of nitrogen can also delay flowering in rice. A recent study identified a rice nitrate transporter (NRT) that can help increase grain yield and accelerate flowering if overexpressed.

In the rice plant, different NRTs move nitrogen from the soil into the roots and move nitrogen compounds throughout the plant. Some NRTs sense nitrogen levels and trigger responses. A study showed that rice OsNRT1.1A can affect both nitrogen use and flowering time and mutant lines lacking this transporter showed decreased use of nitrate and ammonium.

To improve yield and flowering time, the researchers created rice lines that produced extra OsNRT1.1A. The OsNRT1.1A-overexpressing plants grew taller, were greener, and produced more biomass, compared with regular rice grown on the same amount of nitrogen. These plants also pulled more nitrate and ammonium out of the medium in hydroponics experiments. In multi-year field trials, the OsNRT1.1A-overexpressing plants showed improved yields of more than 30% (and up to 60%) in fields with high and low levels of nitrogen fertilization. These plants also flowered one to two weeks earlier than the control rice plants.

For more details, read the press release from the American Society of Plant Biologists.