A research group at Tohoku University has discovered the protein that inhibits the formation of organic nitrogen compounds in plants. The protein could potentially be used to improve plant growth, biomass production, and crop yields.
Nitrogen is important to humans and plants. Plants use nitrate or ammonium in the environment to synthesize organic nitrogen molecules in a process called nitrogen assimilation. Crop production relies on nitrogen fertilizers for efficient nitrogen uptake. However, the mechanism behind nitrogen assimilation is still unknown to scientists.
Multiple proteins mediate nitrogen assimilation, and previous research by this group reported that the protein MYB1 serves a crucial role in inducing the expression of genes necessary for the process to take place, but becomes inhibited in high nitrogen environments. The results revealed that the novel protein NDB1 inactivated MYB1. NDB1 traps MYB1 in the cytoplasm and prevents it from functioning as a transcription factor.
"The NDB1-MYB1 pathway is a key factor in regulating nitrogen assimilation," says Kazuhiko Igarashi, professor at the Department of Biochemistry at Tohoku University's Graduate School of Medicine. "Our discovery is a breakthrough for the field of plant science," he added.
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)

Tohoku University researchers discover that NDB1 controls nitrogen assimilation in an environmental-nitrogen-dependent manner. In nitrogen-rich conditions, it is conceivable that MYB1 is bound by the NDB1 protein. This interaction interferes with the nuclear translocation of MYB1 and therefore, nitrogen assimilation is suppressed. Photo Source: Imamura, et al.