The Nicotiana sylvestris extensin gene, Ext 1.2A, is expressed in the root transition zone and upon wounding.
The Ext 1.2A gene of Nicotiana sylvestris L. encoding an extensin, a cell wall structural protein, was characterized. Ext 1.2A encodes a polypeptide of 311 amino acids having a highly repetitive structure and showing extensin features such as Ser-(Pro)(4) repeats and a high content of Tyr and Lys. The expression profile of the gene was demonstrated using the reporter GUS (beta-glucuronidase) fused to its promoter region (-630/+124, relative to the transcription start site) and by RNA gel blots. The results show that the (-630/+124) Ext 1.2A/GUS gene fusion is expressed in the root transition zone, where cells undergo an isodiametric growth but have not yet reached the rapid elongation phase, in stem inner and outer phloems and in cortical cells at the stem/petiole junction. The Ext 1.2A gene is also induced after wounding of stems, ribs, leaves or roots. The gene fusion is expressed in stem cortical cells, in ribs and at leaf edges upon wounding. These data suggest that the (-630/+124) promoter region contains regulatory elements responsible for expression in roots and stems, as well as for response to wounding in stems and leaves.
Guzzardi
Patricia
P
Institut de Biologie Moléculaire des Plantes, UPR CNRS 2356, 12 rue du Général Zimmer, 67000 Strasbourg, France.
Genot
Geneviève
G
Jamet
Elisabeth
E
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005966:Glucuronidase / Q000378:metabolism; D006023:Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000378:metabolism*; D018547:Plant Stems / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D014026:Nicotiana / Q000235:genetics*; D014158:Transcription, Genetic
D006023:Glycoproteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C005488:extensin protein, plant; D005966:Glucuronidase