Open AccessStudies of the Uptake of Nitrate in Barley
Author(s) -
M. Yaeesh Siddiqi,
Anthony D. M. Glass,
Thomas J. Ruth,
Thomas W. Rufty
Publication year - 1990
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.93.4.1426
Subject(s) - hordeum vulgare , mole , nitrate , chemistry , range (aeronautics) , poaceae , botany , analytical chemistry (journal) , biology , biochemistry , environmental chemistry , materials science , organic chemistry , composite material
(13)NO(3) (-) was used to investigate patterns of NO(3) (-) influx into roots of barley plants (Hordeum vulgare L. cv Klondike) previously grown with (;induced') or without (;uninduced') a source of external NO(3) (-) ([NO(3) (-)](0)). In both induced and uninduced plants, (13)NO(3) (-) influx was biphasic in the range from 0.005 to 50 moles per cubic meter [NO(3) (-)](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(max) and K(m) values for influx either increased or decreased according to NO(3) (-) pretreatment. By contrast, (13)NO(3) (-) 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.