title: Eugenol enhances the resistance of tomato against tomato yellow leaf curl virus.
abstract: BACKGROUND
  Tomato yellow leaf curl virus disease (TYLCVD) causes severe to economic losses in tomato crops in China. The control of TYLCVD is based primarily on the use of synthetic insecticide to control its vector whitefly (Bemisia tabaci). To look for an alternative method for disease control, we investigated the effect of eugenol on controlling TYLCVD. The potential of eugenol to trigger systemic acquired resistance (SAR) in tomato (Jiangsu 14) plants against TYLCV was also investigated.
  
  
  RESULTS
  In greenhouse experiments, eugenol significantly reduced disease severity when applied as a foliar spray, thus demonstrating a systemic effect. The disease spread rapidly in control plants and by the end of the experiment almost all control plants showed severe symptoms. Eugenol also induced H₂O₂ accumulation in tomato plants. Activities of peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were significantly induced compared with those of control plants. As further consequences, increase of salicylic acid (SA) levels and expression of PR-1 proteins, a molecular marker of SAR in tomato, could also be observed.
  
  
  CONCLUSIONS
  This is the first report of eugenol as an elicitor and its ability to suppress plant virus diseases under greenhouse conditions. It is suggested that eugenol has the potential to be an effective biocontrol agent against TYLCV in tomato plants.
authors.affiliation: Department of Plant Protection, Univesity of Nanjing Agriculture, Nanjing, 210095, China; Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wang
authors.forename: Yongjian
authors.initials: Y
authors.lastname: Fan
mesh_terms: D000336:Aerosols; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D053839:Begomovirus / Q000254:growth & development / Q000276:immunology*; D004156:Catechol Oxidase / Q000737:chemistry / Q000378:metabolism; D002681:China; D060467:Disease Resistance / Q000187:drug effects*; D004790:Enzyme Induction / Q000187:drug effects; D005054:Eugenol / Q000008:administration & dosage / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000821:virology; D009195:Peroxidase / Q000737:chemistry / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000737:chemistry / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D018515:Plant Leaves / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000821:virology; D010940:Plant Proteins / Q000819:agonists / Q000378:metabolism; D020156:Salicylic Acid / Q000819:agonists / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000336:Aerosols; D000890:Anti-Infective Agents; D007527:Isoenzymes; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; D005054:Eugenol; D006861:Hydrogen Peroxide; D004156:Catechol Oxidase; D009195:Peroxidase; D010650:Phenylalanine Ammonia-Lyase; D020156:Salicylic Acid
keywords: eugenol; hydrogen peroxide; pathogenesis-related proteins; systemic acquired resistance; tomato yellow leaf curl virus