Lichen depsides and depsidones reduce symptoms of diseases caused by tobacco mosaic virus (TMV) in tobacco leaves.
Two depsides and five depsidones, isolated from lichens, were tested to determine their in vivo protective effects on tobacco leaves challenged with tobacco mosaic virus (TMV). The results indicate that most of these compounds are able to reduce either the number and/or the size of necrotic lesions following virus infection. Pannarin, 1'-chloro-pannarin and stictic acid provided the more effective protective results, reducing by at least 45% the number and size of lesions. Real Time PCR assays were used to explore the target of action against TMV by examining the response behavior of genes involved in the plant defense mechanism. The application of the lichen substances did not lead to changes in the transcriptional levels of pathogen-related (PR1a), allene oxide synthase 2 (AOS2) or oxophytodienoate reductase (OPR3) genes. Thus, the protection observed in the tobacco leaves treated with the lichen compounds may be mediated by a mechanism which does not involved the SA- or JA-mediated defensive plant response. A possible structure-activity relationship is presented.
Laboratorio de Biología Molecular Vegetal, Centro de Biotecnología D. Alkalay L., Universidad Técnica Federico Santa María, Avda. España 1680, Valparaíso, Chile. ingrid.ramirez@usm.cl
Ingrid
I
Ramírez
Soledad
S
Araya
Marisa
M
Piovano
Marcela
M
Carvajal
Alvaro
A
Cuadros-Inostroza
Luis
L
Espinoza
Juan Antonio
JA
Garbarino
Hugo
H
Peña-Cortés
D053630:Depsides / Q000494:pharmacology*; D007783:Lactones / Q000494:pharmacology*; D008011:Lichens / Q000737:chemistry*; D010935:Plant Diseases / Q000628:therapy*; D018515:Plant Leaves / Q000382:microbiology; D013329:Structure-Activity Relationship; D014026:Nicotiana / Q000382:microbiology*; D014027:Tobacco Mosaic Virus / Q000187:drug effects*
D053630:Depsides; D007783:Lactones; C000875:depsidone