Calcium effects on stomatal movement in Commelina communis L

Journal Article · Fri Jul 01 00:00:00 EDT 1988 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.87.3.583· OSTI ID:7164505

Schwartz, A; Ilan, N; Grantz, D A ^[1]

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1. Hebrew Univ. of Jerusalem, Rehovot (Israel)

Stomatal movements depends on both ion influx and efflux: attainment of steady state apertures reflects modulation of either or both processes. The role of Ca{sup 2+} in those two processes was investigated in isolated epidermal strips of Commelina communis, using the Ca{sup 2+} chelator EGTA to reduce apoplastic (Ca{sup 2+}). The results suggest that a certain concentration of Ca{sup 2+} is an absolute requirement for salt efflux and stomatal closure. EGTA (2 millimolar) increased KCl-dependent stomatal opening in darkness and completely inhibited the dark-induced closure of initially open stomata. Closure was inhibited even in a KCl-free medium. Thus, maintenance of stomata in the open state does not necessarily depend on continued K{sup +} influx but on the inhibition of salt efflux. Opening in the dark was stimulated by IAA in a concentration-dependent manner, up to 15.4 micrometer without reaching saturation, while the response to EGTA leveled off at 9.2 micrometer. IAA did not inhibit stomatal closure to the extent it stimulated opening. The response to IAA is thus consistent with a primary stimulation of opening, while EGTA can be considered a specific inhibitor of stomatal closing since it inhibits closure to a much larger degree than it stimulates opening. CO{sub 2} causes concentration-dependent reduction in the steady state stomatal aperture. EGTA completely reversed CO{sub 2}-induced closing of open stomata but only partially prevented the inhibition of opening.

• OSTI ID: 7164505
• Journal Information: Plant Physiology; (USA), Vol. 87:3; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CALCIUM COMPOUNDS
BIOLOGICAL EFFECTS
CARBON DIOXIDE
EGTA
POTASSIUM CHLORIDES
STOMATA
BIOLOGICAL FUNCTIONS
VISIBLE RADIATION
PHYSIOLOGY
PLANTS
ALCOHOLS
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHELATING AGENTS
CHLORIDES
CHLORINE COMPOUNDS
ELECTROMAGNETIC RADIATION
FUNCTIONS
GLYCOLS
HALIDES
HALOGEN COMPOUNDS
HYDROXY COMPOUNDS
OPENINGS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
RADIATIONS
560300* - Chemicals Metabolism & Toxicology