title: Control of Phytophthora nicotianae disease, induction of defense responses and genes expression of papaya fruits treated with Pseudomonas putida MGP1.
abstract: BACKGROUND
  Biological control is a potential strategy to reduce post-harvest decay in several fruits. Little research has been carried out on the effects of endophytic bacterium on post-harvest blight caused by Phytophthora nicotianae in papaya. In this work, the biocontrol activity of Pseudomonas putida MGP1 on this disease and its possible mechanisms, including changes of defensive enzyme activities, total phenolic content and mRNA levels of two important genes, were investigated.
  
  
  RESULTS
  Fruits treated with MGP1 showed a significant lower disease index and demonstrated increases in chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase, peroxidase, polyphenol oxidase and catalase activities and total phenolic content. In addition, the expression levels of pathogenesis related protein 1 gene (PR1) and non-expressor of PR1 gene (NPR1) in papaya fruits were elevated by MGP1 treatment. CONCLUSION The results indicated that papaya fruits were responsive to the endophytic bacterium Ps. putida, which could activate defensive enzymes and genes and thereby induce host disease resistance.
authors.affiliation: College of Food Science and Engineering, Shandong Agricultural University, Taian 271018, People's Republic of China.
authors.forename: Jingying
authors.initials: J
authors.lastname: Shi
authors.forename: Aiyuan
authors.initials: A
authors.lastname: Liu
authors.forename: Xueping
authors.initials: X
authors.lastname: Li
authors.forename: Weixin
authors.initials: W
authors.lastname: Chen
mesh_terms: D029441:Carica; D004156:Catechol Oxidase / Q000378:metabolism; D002688:Chitinases / Q000378:metabolism; D005638:Fruit / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D015870:Gene Expression; D043326:Glucan 1,3-beta-Glucosidase / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D010572:Pest Control, Biological / Q000379:methods*; D010636:Phenols / Q000032:analysis; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D010838:Phytophthora; D010935:Plant Diseases / Q000469:parasitology / Q000517:prevention & control*; D010940:Plant Proteins / Q000235:genetics; D016958:Pseudomonas putida / Q000502:physiology*
chemical_list: D010636:Phenols; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; D004156:Catechol Oxidase; D010544:Peroxidases; D009195:Peroxidase; D002688:Chitinases; D043326:Glucan 1,3-beta-Glucosidase; D010650:Phenylalanine Ammonia-Lyase