RRC ID 71516
Author Lin J, Roswanjaya YP, Kohlen W, Stougaard J, Reid D.
Title Nitrate restricts nodule organogenesis through inhibition of cytokinin biosynthesis in Lotus japonicus.
Journal Nat Commun
Abstract Legumes balance nitrogen acquisition from soil nitrate with symbiotic nitrogen fixation. Nitrogen fixation requires establishment of a new organ, which is a cytokinin dependent developmental process in the root. We found cytokinin biosynthesis is a central integrator, balancing nitrate signalling with symbiotic acquired nitrogen. Low nitrate conditions provide a permissive state for induction of cytokinin by symbiotic signalling and thus nodule development. In contrast, high nitrate is inhibitory to cytokinin accumulation and nodule establishment in the root zone susceptible to nodule formation. This reduction of symbiotic cytokinin accumulation was further exacerbated in cytokinin biosynthesis mutants, which display hypersensitivity to nitrate inhibition of nodule development, maturation and nitrogen fixation. Consistent with this, cytokinin application rescues nodulation and nitrogen fixation of biosynthesis mutants in a concentration dependent manner. These inhibitory impacts of nitrate on symbiosis occur in a Nlp1 and Nlp4 dependent manner and contrast with the positive influence of nitrate on cytokinin biosynthesis that occurs in species that do not form symbiotic root nodules. Altogether this shows that legumes, as exemplified by Lotus japonicus, have evolved a different cytokinin response to nitrate compared to non-legumes.
Volume 12(1)
Pages 6544
Published 2021-11-11
DOI 10.1038/s41467-021-26820-9
PII 10.1038/s41467-021-26820-9
PMID 34764268
PMC PMC8585978
MeSH Cytokinins / metabolism Lotus / metabolism* Nitrogen Fixation / physiology Plant Root Nodulation / physiology Root Nodules, Plant / metabolism
IF 12.121
Lotus / Glycine Gifu B-129