RRC ID 59888
Author Wu L, Sadhukhan A, Kobayashi Y, Ogo N, Tokizawa M, Agrahari RK, Ito H, Iuchi S, Kobayashi M, Asai A, Koyama H.
Title Involvement of phosphatidylinositol metabolism in aluminum-induced malate secretion in Arabidopsis.
Journal J Exp Bot
Abstract 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.
Volume 70(12)
Pages 3329-3342
Published 2019-6-28
DOI 10.1093/jxb/erz179
PII 5448962
PMID 30977815
MeSH Aluminum / metabolism* Arabidopsis / metabolism* Arabidopsis Proteins / genetics* Arabidopsis Proteins / metabolism Malates / metabolism* Organic Anion Transporters / genetics* Organic Anion Transporters / metabolism Phosphatidylinositols / metabolism*
IF 5.36
Times Cited 1
Arabidopsis / Cultured plant cells, genes sja05800