By using biochemical, immunological, and molecular strategies we have identified and cloned a cDNA encoding a protease from tomato (Lycopersicon esculentum) plants (P69B) that is part of a proteolytic system activated in the plant as a result of infection with citrus exocortis viroid. This new protease is closely related, in terms of amino acid sequence and structural organization, to the previ...

Cell-free synthesis of citrus exocortis viroid (CEV) in nuclei-rich preparations from infected Gynura aurantiaca was optimum at 18-24 degrees C. Incubation of reaction mixtures at higher temperatures (30-36 degrees C) resulted in an increase of CEV linear molecules and the recovery of incomplete or nicked newly synthesized RNA species. Although the Mg(2+) optimum (2.5-5 mM) for CEV synthesis wa...

in this study, the possible infection of thomson navel, moro blood sweet orange, page mandarin and webber pomelo with citrus viroids was investigated. biological indexing was performed by grafting on etrog citron (c. medica) and maintained in temperature-controlled greenhouse. after inoculation, rna was extracted by sds– potassium acetate method. detection of citrus viroids was done reverse tra...