Occurrence and involvement of adenylate cyclase activity in the first step of tobacco mosaic virus infection of Nicotiana tabacum cv Xanthi nc leaves

• Published in: Biochimica et biophysica acta Vol. 882; no. 1; pp. 44 - 50
• Main Authors: Abad, P., Guibbolini, M., Poupet, A., Lahlou, B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 03.06.1986; Elsevier; North-Holland
• Subjects: Adenoviridae; Adenylate cyclase; Applied sciences; Biological and medical sciences; enzyme activity; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; leaves; Microbiology; Nicotiana tabacum; Other techniques and industries; Phytopathology. Animal pests. Plant and forest protection; Plant viruses and viroids; Replicative cycle, interference, host-virus relations, pathogenicity, miscellaneous strains; Systematics. Structure, properties and multiplication. Genetics; Tobacco leaf; Tobacco mosaic virus; Virology; Virus infection; Adenylate cyclase; Virus infection; Tobacco leaf; TMV, tobacco mosaic virus; Hepes, 4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid; Virus; Tobacco mosaic virus; Dicotyledones; Angiospermae; Tobamovirus; Spermatophyta; Phytopathogen; Solanaceae; Nicotiana tabacum; Physiopathology
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(86)90053-X

Adenylate cyclase activity and its involvement in a physiopathological process (virus infection) were observed in a higher plant, Nicotiana tabacum cv Xanthi nc. The enzyme was characterized in leaves by measuring the conversion of [α- 32P]ATP into cyclic [α- 32P]AMP using a cell membrane preparation. The basal enzyme activity was 1–2 pmol/min per mg protein, was linear with time and protein concentration, and had a temperature optimum between 20 and 25% C. The K m for ATP was 2 mM in the presence or absence of stimulators. GTP (10 −7 M) increased both basal and sodium fluoride-stimulated activities. During the hypersensitive reaction which follows tobacco mosaic virus (TMV) infection, we detected in the first 10 min a 40–80% increase in the basal activity. These results indicate that cAMP could play an important role by mediating the viral and plant host-cell interaction. The rapid pulse-release of cAMP leads us to propose that this nucleotide may, as in animal tissues, represent a secondary messenger in higher plants.