title: Differential expression of 10 sweetpotato peroxidase genes in response to bacterial pathogen, Pectobacterium chrysanthemi.
abstract: To understand the function of each peroxidase (POD, EC 1.11.1.7) in terms of biotic stress, changes in POD specific activity and expression of 10 POD genes were investigated in four cultivars of sweetpotato (Ipomoea batatas) after infection with Pectobacterium chrysanthemi. POD specific activity (units mg(-1) protein) increased from 16 h after inoculation (HAI) in three varieties. POD activities of two cultivars, Shinwhangmi and White Star, reached a maximum level at 24 HAI by about three times compared to mock treatment (MT), and then decreased, whereas those of Zami and Yulmi continuously increased until 36 HAI. Native gel analysis revealed that one POD isoenzyme with a high electrophoretic mobility significantly increased in response to pathogen infection in all cultivars. Additionally, 10 POD genes displayed differential expression patterns upon bacterial infection by northern analysis. Several POD genes such as swpa2, swpa3, swpa4, swpa5, swpb1 were induced upon bacterial infection, but other genes were not. Particularly, swpa4 gene was markedly expressed in response to bacterial infection in four different cultivars, suggesting that this gene has a stress-inducible promoter. These results indicate that some specific POD isoenzymes are involved in defense in relation to pathogenesis of P. chrysanthemi in sweetpotato plants.
authors.affiliation: Laboratory of Environmental Biotechnology, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 52 Eoen-dong, Yuseong-gu, Daejeon 305-806, South Korea.
authors.forename: In-Chang
authors.initials: IC
authors.lastname: Jang
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Kee-Yeun
authors.initials: KY
authors.lastname: Kim
authors.forename: Suk-Yoon
authors.initials: SY
authors.lastname: Kwon
authors.forename: Jong-Guk
authors.initials: JG
authors.lastname: Kim
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Kwak
mesh_terms: D015152:Blotting, Northern; D004591:Electrophoresis, Polyacrylamide Gel; D027723:Ipomoea batatas / Q000201:enzymology* / Q000382:microbiology*; D044043:Pectobacterium / Q000378:metabolism*; D009195:Peroxidase / Q000737:chemistry*; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms; D013045:Species Specificity; D013997:Time Factors
chemical_list: D020033:Protein Isoforms; D009195:Peroxidase