Studies of the uptake of nitrate in barley. I. Kinetics of sup 13 NO sub 3 sup minus influx. [Hordeum vulgare L]

Journal Article · Wed Aug 01 00:00:00 EDT 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.93.4.1426· OSTI ID:5941587

Siddiqi, M Y; Glass, A D.M.; Ruth, T J; Rufty, Jr, T W ^[1]

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1. Univ. of British Columbia, Vancouver (Canada) North Carolina State Univ., Raleigh (USA)

{sup 13}NO{sub 3}{sup {minus}} was used to investigate patterns of NO{sub 3}{sup {minus}} influx into roots of barley plants (Hordeum vulgare L. cv Klondike) previously grown with (induced) or without (uninduced) a source of external NO{sub 3}{sup {minus}} ((NO{sub 3}{sup {minus}}){sub 0}). In both induced and uninduced plants, {sup 13}NO{sub 3}{sup {minus}} influx was biphasic in the range from 0.005 to 50 moles per cubic meter (NO{sub 3}{sup {minus}}){sub 0}. In the low concentration range (<1 mole per cubic meter for induced plants and <0.3 mole per cubic meter for uninduced plants), influx was saturable and V{sub max} and K{sub m} values for influx either increased or decreased according to NO{sub 3}{sup {minus}} pretreatment. By contrast, {sup 13}NO{sub 3}{sup {minus}} influx in the high concentration range revealed a strictly linear concentration dependence. These fluxes appeared to be mediated by a constitutive, rather than an inducible, transport system.

• OSTI ID: 5941587
• Journal Information: Plant Physiology; (USA), Vol. 93:4; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BARLEY
PHYSIOLOGY
NITRATES
ROOT ABSORPTION
BIOCHEMICAL REACTION KINETICS
NITROGEN 13
TRACER TECHNIQUES
UPTAKE
ABSORPTION
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CEREALS
ELECTRON CAPTURE RADIOISOTOPES
GRASS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
LILIOPSIDA
MAGNOLIOPHYTA
MINUTES LIVING RADIOISOTOPES
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
PLANTS
RADIOISOTOPES
REACTION KINETICS
551001* - Physiological Systems- Tracer Techniques