A pectate lyase from Zinnia elegans is auxin inducible
Por:
Domingo C., Roberts K., Stacey N.J., Connerton I., Ruíz-Teran F., McCann M.C.
Publicada:
1 ene 1998
Resumen:
The Zinnia mesophyll cell system consists of isolated leaf mesophyll cells in culture that can be induced, by auxin and cytokinin, to reproducibly trans-differentiate into tracheary elements (TE) after 96 h, while in the presence of auxin alone the cells simply elongate. In a search for genes involved in modifications to cell-wall architecture before any overt signs of cell differentiation, a differential hybridization of a 72-h cDNA library with probes from mRNA at time-points of 24 h and 72 h was done revealing a number of transcripts up-regulated between these times. One of these cDNAs shows homology to pectate lyase, a pectin-degrading enzyme. The complete cDNA sequence (ZePel) corresponds to a translated protein of 44 kDa with an N-terminal signal peptide of about 2 kDa, and one potential N-glycosylation site. Northern analysis confirms that the strong expression of this gone during TE induction occurs at a very early stage of the process and is due solely to the presence of auxin in the induction medium. in situ hybridization studies in young Zinnia stems show that ZePel expression is associated with vascular bundles end shoot primordia. Recombinant protein made in Escherichia coli possesses calcium-dependent pectate lyase activity. Pectate lyase activity is detected in elongating and differentiating in vitro cell populations. The role of this enzyme in remodelling the cell wall during cell elongantion and differentiation is discussed.
Filiaciones:
Domingo C.:
Department of Cell Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, United Kingdom
Roberts K.:
Department of Cell Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, United Kingdom
Stacey N.J.:
Department of Cell Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, United Kingdom
Connerton I.:
Dept. of Food Macromolecular Science, Institute of Food Research, Reading Laboratory, Earley Gate, Reading RG6 6BZ, United Kingdom
Ruíz-Teran F.:
Dept. of Food Macromolecular Science, Institute of Food Research, Reading Laboratory, Earley Gate, Reading RG6 6BZ, United Kingdom
Departamento de Alimentos Ed. E, Facultad de Química, Ciudad Universitaria, México DF
McCann M.C.:
Department of Cell Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, United Kingdom
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