Research Note Cloning and Expression Analysis of a Viroid-induced Peroxidase from Tomato Plants. Pablo Vera, Pablo Tornero, and Vicente Conejero. Departament of Biotechnology, Laboratory of Biochemistry and Molecular Biology, Universidad Politécnica de Valencia, Camino de Vera 14, 46021-Valencia, Spain. MPMI 6:790-794. Accepted 11 August 1993. Copyright 1993 The American Phytopathological Society.

Differential hybridization was used to detect transcripts induced both by ethylene and by viroid infection in tomato plants.  A cDNA clone encoding a putative peroxidase was isolated and characterized.  DNA sequencing revealed high homology with a lignin-peroxidase from tobacco.  Northern blot analysis showed specific induction of this peroxidase gene in viroid-infected plants.  an increase in the level of mRNA accumulation is obtained by ethylene treatment, reinforcing the idea that ethylene is a mediator in the response of tomato plants to viroid infection.