NYU team identifies HHO5 as a nitrogen-satiety regulator in plants

New York University researchers have identified molecular players that help plants register nitrogen sufficiency, a finding that could support crops that take up more soil nitrogen and reduce fertilizer use, Phys.org reported on a study in The Plant Cell. Co-senior author Gloria Coruzzi and collaborators focused on dose-dependent nitrogen gene regulators and homed in on the protein HHO5. Phys.org reported that HHO5 levels rise when plants hold enough organic nitrogen, then both promote organic nitrogen and amino acid metabolism genes and inhibit genes for taking up more inorganic nitrogen from soil. When HHO5 acts with partner regulator WRKY21, it can activate organic nitrogen signaling; alone it turns off inorganic nitrogen uptake genes. Arabidopsis plants lacking HHO5 absorbed nearly three times more nitrogen than plants with normal HHO5 levels under specific nitrogen conditions, the report said. NYU has filed a patent application covering the research. The paper lists DOI 10.1093/plcell/koag201.