RESUMEN

Methods for the transformation of barley using Agrobacterium-mediated techniques have been available for the past 10 years. Agrobacterium offers a number of advantages over biolistic-mediated techniques in terms of efficiency and the quality of the transformed plants produced. This chapter describes a simple system for the transformation of barley based on the infection of immature embryos with Agrobacterium tumefaciens followed by the selection of transgenic tissue on media containing the antibiotic hygromycin. The method can lead to the production of large numbers of fertile, independent transgenic lines. It is therefore ideal for studies of gene function in a cereal crop system.

Asunto(s)

Agrobacterium tumefaciens/metabolismo , Técnicas de Transferencia de Gen , Hordeum/genética , Hordeum/microbiología , Transformación Genética , Técnicas de Cocultivo , Medios de Cultivo , Hordeum/citología , Hordeum/crecimiento & desarrollo , Plantas Modificadas Genéticamente , Semillas/citología , Semillas/genética , Semillas/crecimiento & desarrollo , Semillas/microbiología , Técnicas de Cultivo de Tejidos

RESUMEN

The mutant regulator of APX2 1-1 (rax1-1) was identified in Arabidopsis thaliana that constitutively expressed normally photooxidative stress-inducible ASCORBATE PEROXIDASE2 (APX2) and had >/=50% lowered foliar glutathione levels. Mapping revealed that rax1-1 is an allele of gamma-GLUTAMYLCYSTEINE SYNTHETASE 1 (GSH1), which encodes chloroplastic gamma-glutamylcysteine synthetase, the controlling step of glutathione biosynthesis. By comparison of rax1-1 with the GSH1 mutant cadmium hypersensitive 2, the expression of 32 stress-responsive genes was shown to be responsive to changed glutathione metabolism. Under photo-oxidative stress conditions, the expression of a wider set of defense-related genes was altered in the mutants. In wild-type plants, glutathione metabolism may play a key role in determining the degree of expression of defense genes controlled by several signaling pathways both before and during stress. This control may reflect the physiological state of the plant at the time of the onset of an environmental challenge and suggests that changes in glutathione metabolism may be one means of integrating the function of several signaling pathways.

Asunto(s)

Arabidopsis/genética , Arabidopsis/metabolismo , Glutamato-Cisteína Ligasa/metabolismo , Glutatión/biosíntesis , Estrés Oxidativo/fisiología , Peroxidasas/metabolismo , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/biosíntesis , Proteínas de Arabidopsis/genética , Infecciones Bacterianas/genética , Infecciones Bacterianas/metabolismo , ADN Complementario/análisis , ADN Complementario/genética , Regulación hacia Abajo/genética , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Genes de Plantas/genética , Glutamato-Cisteína Ligasa/genética , Proteínas de Choque Térmico/biosíntesis , Proteínas de Choque Térmico/genética , Luz , Datos de Secuencia Molecular , Mutagénesis , Mutación/genética , Estrés Oxidativo/genética , Estrés Oxidativo/efectos de la radiación , Peroxidasas/genética , Estimulación Luminosa , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Transducción de Señal/genética