Are calcium ions and calcium channels involved in the mechanisms of Cu2+ toxicity in bean plants? The influence of leaf age

Title:

Are calcium ions and calcium channels involved in the mechanisms of Cu2+ toxicity in bean plants? The influence of leaf age

Creator:

Maksymiec, W. and Baszyński, T.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:19561787-8b65-4dce-a01a-6e9308e7c1fe
uuid:19561787-8b65-4dce-a01a-6e9308e7c1fe
issn:0300-3604
doi:10.1023/A:1007007929102

Subject:

chlorophyll fluorescence, copper, lanthanum, Phaseolus coccineus, photosystem 2, senescence, toxicity, and verapamil

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

The influence of calcium channel blockers and ionophore on Cu2+-induced changes of the photosynthetic activity of runner bean plants (Phaseolus coccineus L.) was investigated. Excess Cu2+ was applied to leaves by injection or via the roots to examine a short/local or a long time/systemic effect of this metal, respectively. The changes in fluorescence parameters indicated that the mechanism of toxic action of Cu2+ ions on the photosynthetic apparatus was only partially connected with Ca2+ or Ca2+ channels. In young plants Ca2+ diminished especially photochemical and nonphotochemical dissipative processes induced by short- and long-term influence of excess Cu2+. Blocking of Ca2+ channels did not change direct Cu2+ action on the photosynthetic activity, however, their opening distinctly intensified the inhibitory effect of the metal. After a longer accumulation peri od the effect of Cu2+ ions did not change significantly due to modified Ca2+ penetration through membranes (except that caused by La3+). Copper directly introduced into older leaves diminished only at its highest concentration the activity both of the donor and acceptor sides of photosystem 2 (PS2) connected with Rfd decrease and increase of LNU. A similar effect was observed also after a long-term Cu2+ action, but disturbances on the acceptor side of PS2 were observed only at a higher Ca2+ content in the nutrient solution. Ca2+ ions, particularly after openning of channels, intensified direct inhibitory Cu2+ action on the photosynthetic activity expressed by decreased values of Fv/F0 and Rfd. Lanthanum and verapamil, at a lower Ca2+ content in the medium, decreased the photosynthetic activity of Cu2+-treated plants. This effect was also seen after additional Ca2+ supply to the leaves. and W. Maksymiec, T. Baszyński.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

267-278

Source:

Photosynthetica | 1999 Volume:36 | Number:1-2

Harvested from:

CDK

Metadata only:

false