CHARACTERIZATION OF CATALASE GENES OF POPOLAR (POPULUS DELTOIDES): GENOMIC STRUCTURE AND EXPRESSION ANALYSIS

Catalases (CAT) are part of primary defense against cell oxidation induced during abiotic stress conditions such as chilling, drought, salt and ozone Catalase may play also an important role in the signal transduction of the defence response in the plants leading to the development of SAR (1). Plant catalases are encoded by a small gene family, usually three or at most four isoenzyme-genes in one species. Studies performed comparing the exon-intron structures of known genomic sequences, indicate that intron positions are conserved and suggest the existence of an ancestral catalase gene containing seven introns (2). Each catalase isoenzyme shows a distinct spatial and temporal pattern of expression through the entire life cycle of the plant, which may account for the diverse roles played by plant catalases. As a first step to study the catalases in poplar (Populus deltoides), we have isolated four different catalase genes and studied the genomic structure and the expression.