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Una glutatión S-transferasa involucrada en la transferencia vacuolar codificada por el gen del maíz Bronze-2
K A Marrs1, M R Alfenito, A M Lloyd
1Department of Biological Sciences, Stanford University, California 94305-5020, USA.
Nature
|June 1, 1995
Resumen
El gen Bronze-2 en el maíz codifica una enzima glutatión S-transferasa (GST). Esta enzima conjuga las antocianinas con el glutatión, facilitando su transporte a las vacuolas de las plantas.
Área de la Ciencia:
- Bioquímica de las plantas Bioquímica de las plantas.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- Las glutatión S-transferasas (GST) desintoxican a los xenobióticos mediante la formación de conjugados de glutatión.
- Las vacuolas vegetales secuestran varias moléculas, incluidos los conjugados herbicida-glutatión a través de bombas específicas.
- El gen Bronze-2 (Bz2) del maíz es crucial para la biosíntesis de antocianinas y la deposición de pigmentos.
Objetivo del estudio:
- Para determinar la función bioquímica del producto genético del maíz Bronce-2 (Bz2).
- Para investigar el papel de Bz2 en el secuestro de antocianina dentro de las vacuolas de las plantas.
- Explorar posibles mecanismos comunes para el transporte vacuolar de diversas moléculas vegetales.
Principales métodos:
- Expresó el gen Bz2 en maíz, Arabidopsis thaliana y Escherichia coli para evaluar la actividad de GST.
- Las antocianinas conjugadas con glutatión en los protoplastos de maíz que expresan Bz2.2.
- Utilizamos vanadato, un inhibidor de la bomba de glutatión, para estudiar la acumulación vacuolar de antocianina.
Principales resultados:
- Bz2 codifica una enzima glutatión S-transferasa funcional.
- Se encontró que las antocianinas de los protoplastos de maíz que expresan Bz2 están conjugadas con el glutatión.
- El tratamiento con vanadato inhibió la acumulación vacuolar de antocianinas, lo que indica un papel para la bomba de glutatión.
Conclusiones:
- El producto del gen Bz2 es una glutatión S-transferasa involucrada en el metabolismo de la antocianina.
- La glutationación de las antocianinas es esencial para su secuestro vacuolar en el maíz.
- Las plantas pueden emplear un mecanismo común mediado por GST para secuestrar diversas moléculas en vacuolas.
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