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Involvement of the Plasma Membrane Ca 2+ ‐ATPase in the Short‐Term Response of Arabidopsis thaliana Cultured Cells to Oligogalacturonides
Author(s) -
Romani G.,
Bonza M. C.,
Filippini I.,
Cerana M.,
Beffag.,
Michelis M. I.
Publication year - 2004
Publication title -
plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 1435-8603
DOI - 10.1055/s-2004-817848
Subject(s) - efflux , arabidopsis thaliana , atpase , biology , calmodulin , reactive oxygen species , biochemistry , microbiology and biotechnology , ion transporter , biophysics , membrane , enzyme , mutant , gene
Treatment of Arabidopsis thaliana cells with oligogalacturonides (OG) initiates a transient production of reactive oxygen species (ROS), the concentration of which in the medium peaks after about 20 min of treatment. The analysis of OG effects on Ca 2+ fluxes shows that OG influence both Ca 2+ influx and Ca 2+ efflux (measured as 45 Ca 2+ fluxes) in a complex way. During the first 10 ‐ 15 min, OG stimulate Ca 2+ influx and decrease its efflux, while at successive times of treatment, OG cause an increase of Ca 2+ efflux and a slight decrease of its influx. Treatment with sub‐μM concentrations of eosin yellow (EY), which selectively inhibits the Ca 2+ ‐ATPase of plasma membrane (PM), completely prevents the OG‐induced increase in Ca 2+ efflux. EY also suppresses the transient feature of OG‐induced ROS accumulation, keeping the level of ROS in the medium high. The biochemical analysis of PM purified from OG‐treated cells indicates that treatment with OG for 15 to 45 min induces a significant decrease in Ca 2+ ‐ATPase activation by exogenous calmodulin (CaM), and markedly increases the amount of CaM associated with the PM. During the same time span, OG do not influence the expression of At ‐ACA8, the main isoform of PM Ca 2+ ‐ATPase in suspension‐cultured A. thaliana cells, and of CaM genes. Overall, the reported results demonstrate that the PM Ca 2+ ‐ATPase is involved in the response of plant cells to OG and is essential in regulation of the oxidative burst.