The intermediate in a nitrate-responsive ω-amidase pathway in plants may signal ammonium assimilation status.

ABSTRACT: A metabolite of ammonium assimilation was previously theorized to be involved in the coordination of the overall nitrate response in plants. Here we show that 2-hydroxy-5-oxoproline, made by transamination of glutamine, the first product of ammonium assimilation, may be involved in signaling a plant's ammonium assimilation status. In leaves, 2-hydroxy-5-oxoproline met four foundational requirements to be such a signal. First, when it was applied to foliage, enzyme activities of nitrate reduction and ammonium assimilation increased; the activities of key tricarboxylic acid cycle-associated enzymes that help to supply carbon skeletons for amino acid synthesis also increased. Second, its leaf pools increased as nitrate availability increased. Third, the pool size of its precursor, Gln, reflec

SUBMITTER: Unkefer PJ 

PROVIDER: S-EPMC9806585 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature