Tenuazonic acid from Stemphylium loti inhibits the plant plasma membrane H+ -ATPase by a mechanism involving the C-terminal regulatory domain.
New Phytol
; 226(3): 770-784, 2020 05.
Article
in En
| MEDLINE
| ID: mdl-31880817
ABSTRACT
Pathogenic fungi often target the plant plasma membrane (PM) H+ -ATPase during infection. To identify pathogenic compounds targeting plant H+ -ATPases, we screened extracts from 10 Stemphylium species for their effect on H+ -ATPase activity. We identified Stemphylium loti extracts as potential H+ -ATPase inhibitors, and through chemical separation and analysis, tenuazonic acid (TeA) as a potent H+ -ATPase inhibitor. By assaying ATP hydrolysis and H+ pumping, we confirmed TeA as a H+ -ATPase inhibitor both in vitro and in vivo. To visualize in planta inhibition of the H+ -ATPase, we treated pH-sensing Arabidopsis thaliana seedlings with TeA and quantified apoplastic alkalization. TeA affected both ATPase hydrolysis and H+ pumping, supporting a direct effect on the H+ -ATPase. We demonstrated apoplastic alkalization of A. thaliana seedlings after short-term TeA treatment, indicating that TeA effectively inhibits plant PM H+ -ATPase in planta. TeA-induced inhibition was highly dependent on the regulatory C-terminal domain of the plant H+ -ATPase. Stemphylium loti is a phytopathogenic fungus. Inhibiting the plant PM H+ -ATPase results in membrane potential depolarization and eventually necrosis. The corresponding fungal H+ -ATPase, PMA1, is less affected by TeA when comparing native preparations. Fungi are thus able to target an essential plant enzyme without causing self-toxicity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Tenuazonic Acid
/
Arabidopsis
Language:
En
Journal:
New Phytol
Journal subject:
BOTANICA
Year:
2020
Document type:
Article
Affiliation country:
Dinamarca