title: Abscisic acid stimulates the expression of two isoforms of plasma membrane Ca2+-ATPase in Arabidopsis thaliana seedlings.
abstract: AT-ACA8 and AT-ACA9 are two plasma membrane (PM) Ca (2+)-ATPases of ARABIDOPSIS THALIANA. In this article the expression of AT-ACA8, AT-ACA9, and of AT-ACA10, a third isoform of Ca (2+)-ATPase closely related to PM Ca (2+)-ATPases, was analysed and the effect of the hormone abscisic acid (ABA) on the expression level of PM Ca (2+)-ATPase specific transcripts was investigated. In adult plants of A. THALIANA, AT-ACA8 and AT-ACA10 are expressed in all organs considered whereas AT-ACA9 is expressed only in flowers. All isoforms of PM Ca (2+)-ATPases can be detected in young seedlings but the amount of AT-ACA9 mRNA is much lower than those of AT-ACA8 and AT-ACA10. ABA markedly and rapidly stimulates the expression of both AT-ACA8 and AT-ACA9 genes in young seedlings but not that of AT-ACA10. ABA also increases the level of AT-ACA8 protein at the PM, suggesting a role for PM Ca (2+)-ATPases in ABA signalling.
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Milano, Istituto di Biofisica del CNR-Sezione di Milano, Via Celoria 26, 20133 Milano, Italy. cristina.bonza@unimi.it
authors.forename: M
authors.initials: M
authors.lastname: Cerana
authors.forename: M C
authors.initials: MC
authors.lastname: Bonza
authors.forename: R
authors.initials: R
authors.lastname: Harris
authors.forename: D
authors.initials: D
authors.lastname: Sanders
authors.forename: M I
authors.initials: MI
authors.lastname: De Michelis
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D007527:Isoenzymes; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology*
chemical_list: D029681:Arabidopsis Proteins; D007527:Isoenzymes; D000040:Abscisic Acid; C508150:Aca8 protein, Arabidopsis; D000252:Calcium-Transporting ATPases