DEVELOPMENTALLY AND WOUND-REGULATED EXPRESSION OF THE GENE ENCODING ACELL-WALL COPPER AMINE OXIDASE IN CHICKPEA SEEDLINGS

A chickpea cDNA encoding a cell wall copper amine oxidase (CuAO) was c loned and characterised, The 2010 bp open reading frame encodes a prot ein of 76.5 kDa which shares significant primary structure homology wi th other known CuAOs, Southern blot analysis indicates that in chickpe a CuAO is encoded by a single gene or a small gene family. This cDNA w as essential for studying the role of CuAO during seedling development and wound healing in chickpea seedlings. CuAO transcript level and ac tivity were modulated during seedling development in parallel with cel l maturation. Moreover, mechanical wounding induced a rapid increase o f CuAO mRNA accumulation and enzyme activity which remained high durin g the wound-healing process. Aminoguanidine, a specific CuAO inhibitor , decreased the deposition of lignin-suberin barrier along the lesion. CuAO may be a limiting factor in H2O2 production in the cell wall of chickpea seedlings and its expression seems to integrate with the remo delling of plant cell wall occurring during ontogenesis and wound heal ing. (C) 1998 Federation of European Biochemical Societies.