RRC ID 4684
Author Hakoyama T, Watanabe H, Tomita J, Yamamoto A, Sato S, Mori Y, Kouchi H, Suganuma N.
Title Nicotianamine synthase specifically expressed in root nodules of Lotus japonicus.
Journal Planta
Abstract In dicotyledonous plants, nicotianamine synthase (NAS) is thought to play a role in the intercellular transport of iron (Fe). Fe is an essential metal for nitrogen-fixing root nodules of legumes, prompting us to characterize the role of the NAS gene in detail. We previously compared gene-expression profiles in ineffective nodules formed on a Lotus japonicus Fix(-) mutant, sen1, with those in wild-type-effective nodules, and showed that expression of an expressed sequence tag (EST) clone encoding an NAS (EC 2.5.1.43) homologue was repressed in the ineffective nodules. In the present study, two EST clones encoding NAS homologues were found in the EST database. We named them LjNAS1 and LjNAS2. Both were detected as single-copy genes in the L. japonicus genome, and conferred NAS activities in transformed Saccharomyces cerevisiae. LjNAS2 was expressed only in nodules, but LjNAS1 was expressed mainly in leaves, stems, and cotyledons. The level of LjNAS2 transcripts was highest in the nodules 24 days after inoculation with Mesorhizobium loti, and was localized in vascular bundles within the nodules. Expression of LjNAS2 was suppressed in ineffective nodules formed on Fix(-) mutants other than sen1. By contrast, nitrogenase activities of nodules were not influenced in LjNAS2-suppressed plants. We discuss the role of LjNAS2 from the aspect of Fe translocation in nodules.
Volume 230(2)
Pages 309-17
Published 2009-7-1
DOI 10.1007/s00425-009-0944-0
PMID 19455352
MeSH Alkyl and Aryl Transferases / classification Alkyl and Aryl Transferases / genetics Alkyl and Aryl Transferases / metabolism* Alphaproteobacteria / growth & development Blotting, Southern Cotyledon / enzymology Expressed Sequence Tags Gene Expression Regulation, Plant* / genetics Gene Expression Regulation, Plant* / physiology Iron / metabolism Lotus / enzymology* Lotus / genetics Phylogeny Plant Leaves / enzymology Plant Proteins / classification Plant Proteins / genetics Plant Proteins / metabolism* Plant Stems / enzymology Plants, Genetically Modified / enzymology Plants, Genetically Modified / genetics Reverse Transcriptase Polymerase Chain Reaction Root Nodules, Plant / enzymology* Root Nodules, Plant / genetics
IF 3.39
Times Cited 17
WOS Category PLANT SCIENCES
Resource
Lotus / Glycine Gifu B-129 M. loti