title: Real time expression of ACC oxidase and PR-protein genes mediated by Methylobacterium spp. in tomato plants challenged with Xanthomonas campestris pv. vesicatoria.
abstract: Biotic stress like pathogenic infection increases ethylene biosynthesis in plants and ethylene inhibitors are known to alleviate the severity of plant disease incidence. This study aimed to reduce the bacterial spot disease incidence in tomato plants caused by Xanthomonas campestris pv. vesicatoria (XCV) by modulating stress ethylene with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of Methylobacterium strains. Under greenhouse condition, Methylobacterium strains inoculated and pathogen challenged tomato plants had low ethylene emission compared to pathogen infected ones. ACC accumulation and ACC oxidase (ACO) activity with ACO related gene expression increased in XCV infected tomato plants over Methylobacterium strains inoculated plants. Among the Methylobacterium spp., CBMB12 resulted lowest ACO related gene expression (1.46 Normalized Fold Expression), whereas CBMB20 had high gene expression (3.42 Normalized Fold Expression) in pathogen challenged tomato. But a significant increase in ACO gene expression (7.09 Normalized Fold Expression) was observed in the bacterial pathogen infected plants. In contrast, Methylobacterium strains enhanced β-1,3-glucanase and phenylalanine ammonia-lyase (PAL) enzyme activities in pathogen challenged tomato plants. The respective increase in β-1,3-glucanase related gene expressions due to CBMB12, CBMB15, and CBMB20 strains were 66.3, 25.5 and 10.4% higher over pathogen infected plants. Similarly, PAL gene expression was high with 0.67 and 0.30 Normalized Fold Expression, in pathogen challenged tomato plants inoculated with CBMB12 and CBMB15 strains. The results suggest that ethylene is a crucial factor in bacterial spot disease incidence and that methylobacteria with ACC deaminase activity can reduce the disease severity with ultimate pathogenesis-related protein increase in tomato.
authors: Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
authors: W J
authors: WJ
authors: Yim
authors: Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
authors: K Y
authors: KY
authors: Kim
authors: Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
authors: Y W
authors: YW
authors: Lee
authors: Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
authors: S P
authors: SP
authors: Sundaram
authors: Department of Industrial Plant Science and Technology, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
authors: Y
authors: Y
authors: Lee
authors: Department of Environmental and Biological Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea. Electronic address: tomsa@chungbuk.ac.kr.
authors: T M
authors: TM
authors: Sa
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D000598:Amino Acids, Cyclic / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D043326:Glucan 1,3-beta-Glucosidase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018551:Solanum lycopersicum / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology*; D020580:Methylobacterium / Q000201:enzymology*; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000033:anatomy & histology; D060888:Real-Time Polymerase Chain Reaction; D016959:Xanthomonas campestris / Q000502:physiology*
chemical_list: D000598:Amino Acids, Cyclic; D005030:Ethylenes; D010940:Plant Proteins; D049452:Green Fluorescent Proteins; C023863:1-aminocyclopropane-1-carboxylic acid; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D043326:Glucan 1,3-beta-Glucosidase; D010650:Phenylalanine Ammonia-Lyase
keywords: Bacterial spot; Ethylene biosynthetic gene expression; Methylobacterium; PR-proteins; Xanthomonas campestris pv. vesicatoria