Higher Novel L-Cys Degradation Activity Results in Lower Organic-S and Biomass in Sarcocornia than the Related Saltwort, Salicornia.
Plant Physiol
; 175(1): 272-289, 2017 Sep.
Article
em En
| MEDLINE
| ID: mdl-28743765
ABSTRACT
Salicornia and Sarcocornia are almost identical halophytes whose edible succulent shoots hold promise for commercial production in saline water. Enhanced sulfur nutrition may be beneficial to crops naturally grown on high sulfate. However, little is known about sulfate nutrition in halophytes. Here we show that Salicornia europaea (ecotype RN) exhibits a significant increase in biomass and organic-S accumulation in response to supplemental sulfate, whereas Sarcocornia fruticosa (ecotype VM) does not, instead exhibiting increased sulfate accumulation. We investigated the role of two pathways on organic-S and biomass accumulation in Salicornia and Sarcoconia the sulfate reductive pathway that generates Cys and l-Cys desulfhydrase that degrades Cys to H2S, NH3, and pyruvate. The major function of O-acetyl-Ser-(thiol) lyase (OAS-TL; EC 2.5.1.47) is the formation of l-Cys, but our study shows that the OAS-TL A and OAS-TL B of both halophytes are enzymes that also degrade l-Cys to H2S. This activity was significantly higher in Sarcocornia than in Salicornia, especially upon sulfate supplementation. The activity of the sulfate reductive pathway key enzyme, adenosine 5'-phosphosulfate reductase (APR, EC 1.8.99.2), was significantly higher in Salicornia than in Sarcocornia These results suggest that the low organic-S level in Sarcocornia is the result of high l-Cys degradation rate by OAS-TLs, whereas the greater organic-S and biomass accumulation in Salicornia is the result of higher APR activity and low l-Cys degradation rate, resulting in higher net Cys biosynthesis. These results present an initial road map for halophyte growers to attain better growth rates and nutritional value of Salicornia and Sarcocornia.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
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Enxofre
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Chenopodiaceae
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Cisteína
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Amaranthaceae
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Salsola
Idioma:
En
Revista:
Plant Physiol
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Israel