title: Salicylic acid and gentisic acid induce RNA silencing-related genes and plant resistance to RNA pathogens.
abstract: We have observed that treatments with salicylic acid (SA) or gentisic acid (GA) induced resistance to RNA pathogens such as ToMV and CEVd in tomato and Gynura auriantiaca, respectively. Accumulation of SA and GA has been found to occur in plants infected by these pathogens, thus pointing out a possible defence role of both molecules. To study the molecular basis of the observed induced resistance to RNA pathogens the induction of silencing-related genes by SA and GA was considered. For that purpose, we searched for tomato genes which were orthologous to those described in Arabidopsis thaliana, such as AtDCL1, AtDCL2, AtDCL4, AtRDR1, AtRDR2 and AtRDR6, and we tracked their induction in tomato along virus and viroid infections. We observed that CEVd significantly induced all these genes in tomato, with the exception of ToRDR6, being the induction of ToDCL4 the most outstanding. Regarding the ToMV asymptomatic infection, with the exception of ToRDR2, we observed a significant induction of all the indicated silencing-related genes, being ToDCL2 the most induced gene. Subsequently, we analyzed their transcriptional activation by SA and at the time when ToMV was inoculated on plants. ToDCL2, ToRDR1 and ToRDR2 were significantly induced by both SA and GA, whereas ToDCL1 was only induced by SA. Such an induction resulted more effective by SA treatment, which is in agreement with the stronger SA-induced resistance observed. Our results suggest that the observed delay in the RNA pathogen accumulation could be due to the pre-induction of RNA silencing-related genes by SA or GA.
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain.
authors: Laura
authors: L
authors: Campos
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain.
authors: Pablo
authors: P
authors: Granell
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain.
authors: Susana
authors: S
authors: Tárraga
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain.
authors: Pilar
authors: P
authors: López-Gresa
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain.
authors: Vicente
authors: V
authors: Conejero
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain.
authors: José María
authors: JM
authors: Bellés
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain. Electronic address: irodrig@ibmcp.upv.es.
authors: Ismael
authors: I
authors: Rodrigo
authors: Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València (UPV), Consejo Superior de Investigaciones Científicas (CSIC), Spain.
authors: Purificación
authors: P
authors: Lisón
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance / Q000187:drug effects / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005841:Gentisates / Q000378:metabolism* / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics* / Q000821:virology; D034622:RNA Interference; D012328:RNA Viruses / Q000235:genetics*; D012367:RNA, Viral / Q000037:antagonists & inhibitors; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism* / Q000494:pharmacology; D015533:Transcriptional Activation
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D005841:Gentisates; D012367:RNA, Viral; C514575:RDR6 protein, Arabidopsis; D012324:RNA-Dependent RNA Polymerase; C402383:DCL1 protein, Arabidopsis; D043244:Ribonuclease III; D020156:Salicylic Acid; C010925:2,5-dihydroxybenzoic acid
keywords: CEVd; Gene silencing; Gentisic acid; Resistance; Salicylic acid; ToMV; Tomato