Active O-acetylserine-(thiol) lyase A and B confer improved selenium resistance and degrade l-Cys and l-SeCys in Arabidopsis.
J Exp Bot
; 73(8): 2525-2539, 2022 04 18.
Article
en En
| MEDLINE
| ID: mdl-35084469
ABSTRACT
The roles of cytosolic O-acetylserine-(thiol)-lyase A (OASTLA), chloroplastic OASTLB, and mitochondrial OASTLC in plant selenate resistance were studied in Arabidopsis. Impairment in OASTLA and OASTLB resulted in reduced biomass, chlorophyll and soluble protein content compared with selenate-treated OASTLC-impaired and wild-type plants. The generally lower total selenium (Se), protein-Se, organic-sulfur and protein-sulfur (S) content in oastlA and oastlB compared with wild-type and oastlC leaves indicated that Se accumulation was not the main cause for the stress symptoms in these mutants. Notably, the application of selenate positively induced S-starvation markers and the OASTLs, followed by increased sulfite reductase, sulfite oxidase activities, and increased sulfite and sulfide concentrations. Taken together, our results indicate a futile anabolic S-starvation response that resulted in lower glutathione and increased oxidative stress symptoms in oastlA and oastlB mutants. In-gel assays of l-cysteine and l-seleno-cysteine, desulfhydrase activities revealed that two of the three OASTL activity bands in each of the oastl single mutants were enhanced in response to selenate, whereas the impaired proteins exhibited a missing activity band. The absence of differently migrated activity bands in each of the three oastl mutants indicates that these OASTLs are major components of desulfhydrase activity, degrading l-cysteine and l-seleno-cysteine in Arabidopsis.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Selenio
/
Arabidopsis
/
Liasas
Idioma:
En
Revista:
J Exp Bot
Asunto de la revista:
BOTANICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Kazajstán