Rice genes could be key to stemming nitrogen pollution

A team of scientists has genetically engineered new breeds of high-yield varieties of rice, wheat, and other grains that require less fertilizer.
A new study led by Xiangdong Fu surveyed the DNA of 36 rice variety and examined the role of molecules called DELLA, proteins that suppress the absorption of nitrogen in green-revolution crops and make them hungry for more fertilizer. The scientists involved in the study were able to identify two genes that control the nitrogen consumption: one codes the DELLA protein while the other codes for a growth-regulating factor 4 or GRF4 protein.
Fu believes that the GR4, initially thought to increase only grain size and yield, can also counteract the effects of DELLA protein on a plant’s ability to absorb and metabolise nitrogen. When they bred the rice to produce more GR4, they came up with short plants with high yields that require significantly less nitrogen.
The findings were published in Nature on August 15.
Xin Zhang, an environmental scientist who is not involved in the study, is excited about the promise of grains requiring less fertilizer and decrease excess nitrogen from wreaking havoc on the environment.
“Human activity is adding too much nitrogen to the planet,” Zhang stated. “It’s critical to improve the efficiency of the system.”
She explained that due to the use of large amounts of fertilizer in farms all over the world, the human race has doubled the amount of excess nitrogen around the world. Zhang also added that saving the world from nitrogen pollution should not end on producing more nitrogen-efficient crops.
Nathan Mueller, an agricultural system expert from the University of California Irving, agreed that farmers should use more precise methods to identify the right amount of
nitrogen needed by the crops to avoid excesses.
Jennifer Volk, an environmental-quality specialist from the University of Delaware, shared that the next step should be to introduce methods that lessen the potential environmental damage from agriculture. This includes construction of wetlands with plants that filter excess nitrogen and other nutrients before they end up in streams and rivers.