Uptake rates of (86Rb)K+ by seedling roots of six cultivars were measured and compared with K+ content of the root, K+ leakage, H+ efflux, and K+-ATPase activity of a partially purified plasmalemma fraction. Different cultivars showed significantly different rates of (86Rb)K+ uptake. The uptake rates of the first (0–5 min) period did not correlate with K+ content of the seedling roots. The rates of uptake in the 10 to 30 min period, supposed to be active, were negatively correlated with K+ content of the root. Roots consistently leaked K+ during the first 5 min. This leakage was positively correlated with the endogenous K+ content of the tissue. H+ efflux was significantly different among the cultivars and correlated with the K+-ATPase activity of a microsomal fraction partially purified on discontinuous (18/34%) sucrose gradient. The relationships among transport parameters are discussed.
Titolo: | Properties of potassium uptake by seedlings roots of grape cultivars |
Autori: | |
Data di pubblicazione: | 1990 |
Rivista: | |
Abstract: | Uptake rates of (86Rb)K+ by seedling roots of six cultivars were measured and compared with K+ content of the root, K+ leakage, H+ efflux, and K+-ATPase activity of a partially purified plasmalemma fraction. Different cultivars showed significantly different rates of (86Rb)K+ uptake. The uptake rates of the first (0–5 min) period did not correlate with K+ content of the seedling roots. The rates of uptake in the 10 to 30 min period, supposed to be active, were negatively correlated with K+ content of the root. Roots consistently leaked K+ during the first 5 min. This leakage was positively correlated with the endogenous K+ content of the tissue. H+ efflux was significantly different among the cultivars and correlated with the K+-ATPase activity of a microsomal fraction partially purified on discontinuous (18/34%) sucrose gradient. The relationships among transport parameters are discussed. |
Handle: | http://hdl.handle.net/11562/376265 |
Appare nelle tipologie: | 01.01 Articolo in Rivista |