Reactions of corn root tissue to calcium

Journal Article · Mon Oct 01 04:00:00 EDT 1984 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.76.2.403· OSTI ID:6055204

de Quintero, M R; Hanson, J B

Washing corn (Zea mays L.) root tissue in water causes loss of about one-third of the exchangeable Ca/sup 2 +/ over the first 10 to 15 minutes. Upon transfer to K/sup +/-containing solutions, the tissue shows a short period of rapid K/sup +/ influx which subsequently declines. Addition of 0.1 millimolar Ca/sup 2 +/ decreases the initial rapid K/sup +/ influx, but increases the sustained rate of K/sup +/ and Cl/sup -/ uptake. It was confirmed that 0.1 millimolar Ca/sup 2 +/ is more effective than higher concentrations for the initial inhibition, and that Mg/sup 2 +/ will substitute. The inhibition arises from a mild shock affect of restoring Ca/sup 2 +/. With 0.1 millimolar Ca/sup 2 +/ net H/sup +/ efflux is blocked for 10 to 15 minutes and the cells are depolarized by about 30 millivolts. However, 1 millimolar Ca/sup 2 +/ rapidly produces increased K/sup +/ influx and blocks net H/sup +/ efflux for only a few minutes; blockage is preceded by a brief net H/sup +/ influx which may restore and increase ion transport by reactivating the plasmalemma H/sup +/-ATPase. Stimulation of electrogenic H/sup +/-pumping with fusicoccin eliminates the shock responses and minimizes Ca/sup 2 +/ effects on K/sup +/ influx. Fusicoccin also strongly decreases Ca/sup 2 +/ influx, but has no effect on Ca/sup 2 +/ efflux. Ice temperatures and high pH decreased Ca/sup 2 +/ efflux, but uncoupler and chlorpromazine did not. It is suggested that the inhibitory and promotive actions of Ca/sup 2 +/ are manifested through decreases or increases in the protonmotive force. 29 references, 11 figures, 1 table.

• Research Organization: Univ. of Illinois, Urbana
• DOE Contract Number: AC02-76EV00790
• OSTI ID: 6055204
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 76:2; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION
ALKALI METALS
ALKALINE EARTH METALS
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
CALCIUM
CEREALS
CHLORINE
DISTRIBUTION
ELEMENTS
GRASS
HALOGENS
HYDROGEN COMPOUNDS
INHIBITION
KINETICS
MAGNESIUM
MAIZE
MEMBRANE TRANSPORT
METALS
NONMETALS
OXYGEN COMPOUNDS
PH VALUE
PLANTS
POTASSIUM
REACTION KINETICS
ROOT ABSORPTION
ROOTS
TEMPERATURE EFFECTS
TISSUE DISTRIBUTION
UPTAKE
WATER