Involvement of phosphatidylinositol metabolism in aluminum-induced malate secretion in Arabidopsis.

Autor:	Wu L; Applied Biological Sciences, Gifu University, Gifu, Japan., Sadhukhan A; Applied Biological Sciences, Gifu University, Gifu, Japan., Kobayashi Y; Applied Biological Sciences, Gifu University, Gifu, Japan., Ogo N; Graduate Division of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan., Tokizawa M; Applied Biological Sciences, Gifu University, Gifu, Japan., Agrahari RK; Applied Biological Sciences, Gifu University, Gifu, Japan., Ito H; Applied Biological Sciences, Gifu University, Gifu, Japan., Iuchi S; Experimental Plant Division, RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan., Kobayashi M; Experimental Plant Division, RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan., Asai A; Graduate Division of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan., Koyama H; Applied Biological Sciences, Gifu University, Gifu, Japan.
Jazyk:	angličtina
Zdroj:	Journal of experimental botany [J Exp Bot] 2019 Jun 28; Vol. 70 (12), pp. 3329-3342.
DOI:	10.1093/jxb/erz179
Abstrakt:	To identify the upstream signaling of aluminum-induced malate secretion through aluminum-activated malate transporter 1 (AtALMT1), a pharmacological assay using inhibitors of human signal transduction pathways was performed. Early aluminum-induced transcription of AtALMT1 and other aluminum-responsive genes was significantly suppressed by phosphatidylinositol 4-kinase (PI4K) and phospholipase C (PLC) inhibitors, indicating that the PI4K-PLC metabolic pathway activates early aluminum signaling. Inhibitors of phosphatidylinositol 3-kinase (PI3K) and PI4K reduced aluminum-activated malate transport by AtALMT1, suggesting that both the PI3K and PI4K metabolic pathways regulate this process. These results were validated using T-DNA insertion mutants of PI4K and PI3K-RNAi lines. A human protein kinase inhibitor, putatively inhibiting homologous calcineurin B-like protein-interacting protein kinase and/or Ca-dependent protein kinase in Arabidopsis, suppressed late-phase aluminum-induced expression of AtALMT1, which was concomitant with the induction of an AtALMT1 repressor, WRKY46, and suppression of an AtALMT1 activator, Calmodulin-binding transcription activator 2 (CAMTA2). In addition, a human deubiquitinase inhibitor suppressed aluminum-activated malate transport, suggesting that deubiquitinases can regulate this process. We also found a reduction of aluminum-induced citrate secretion in tobacco by applying inhibitors of PI3K and PI4K. Taken together, our results indicated that phosphatidylinositol metabolism regulates organic acid secretion in plants under aluminum stress. (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
Databáze:	MEDLINE
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