Functional properties and differential mode of regulation of the nitrate transporter from a plant symbiotic ascomycete (Articolo in rivista)

Type
Label
  • Functional properties and differential mode of regulation of the nitrate transporter from a plant symbiotic ascomycete (Articolo in rivista) (literal)
Anno
  • 2006-01-01T00:00:00+01:00 (literal)
Alternative label
  • Montanini B., Viscomi AR, Bolchi A., Martin Y., Siverio JM, Balestrini R., Ottonello F. (2006)
    Functional properties and differential mode of regulation of the nitrate transporter from a plant symbiotic ascomycete
    in Biochemical journal (Lond., 1984)
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Montanini B., Viscomi AR, Bolchi A., Martin Y., Siverio JM, Balestrini R., Ottonello F. (literal)
Pagina inizio
  • 125 (literal)
Pagina fine
  • 134 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 394 (literal)
Rivista
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • -Istituto per la Protezione delle Piante - CNR, Torino -Dipartimento di Biochimica e Biologia Molecolare, Università di Parma (literal)
Titolo
  • Functional properties and differential mode of regulation of the nitrate transporter from a plant symbiotic ascomycete (literal)
Abstract
  • Nitrogen assimilation by plant symbiotic fungi plays a central role in the mutualistic interaction established by these organisms, as well as in nitrogen flux in a variety of soils. In the present study, we report on the functional properties, structural organization and distinctive mode of regulation of TbNrt2 (Tuber borchii NRT2 family transporter), the nitrate transporter of the mycorrhizal ascomycete T. borchii. As revealed by experiments conducted in a nitrate-uptake-defective mutant of the yeast Hansenula polymorpha, TbNrt2 is a high-affinity transporter (K(m)=4.7 microM nitrate) that is bispecific for nitrate and nitrite. It is expressed in free-living mycelia and in mycorrhizae, where it preferentially accumulates in the plasma membrane of root-contacting hyphae. The TbNrt2 mRNA, which is transcribed from a single-copy gene clustered with the nitrate reductase gene in the T. borchii genome, was specifically up-regulated following transfer of mycelia to nitrate- (or nitrite)-containing medium. However, at variance with the strict nitrate-dependent induction commonly observed in other organisms, TbNrt2 was also up-regulated (at both the mRNA and the protein level) following transfer to a nitrogen-free medium. This unusual mode of regulation differs from that of the adjacent nitrate reductase gene, which was expressed at basal levels under nitrogen deprivation conditions and required nitrate for induction. The functional and expression properties, described in the present study, delineate TbNrt2 as a versatile transporter that may be especially suited to cope with the fluctuating (and often low) mineral nitrogen concentrations found in most natural, especially forest, soils. (literal)
Prodotto di
Autore CNR
Insieme di parole chiave

Incoming links:


Autore CNR di
Prodotto
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi
Insieme di parole chiave di
data.CNR.it