title: Metabolic Response of Strawberry (Fragaria x ananassa) Leaves Exposed to the Angular Leaf Spot Bacterium (Xanthomonas fragariae).
abstract: Plants have evolved various defense mechanisms against biotic stress. The most common mechanism involves the production of metabolites that act as defense compounds. Bacterial angular leaf spot disease (Xanthomonas fragariae) of the strawberry (Fragaria x ananassa) has become increasingly destructive to strawberry leaves and plant production. In this study, we examined metabolic changes associated with the establishment of long-term bacterial disease stress using UPLC-QTOF mass spectrometry. Infected leaves showed decreased levels of gallic acid derivatives and ellagitannins, which are related to the plant defense system. The levels of phenylalanine, tryptophan, and salicylic acid as precursors of aromatic secondary metabolites were increased in inoculated leaves, whereas levels of coumaric acid, quinic acid, and flavonoids were decreased in infected plants, which are involved in the phenylpropanoid pathway. In addition, phenylalanine ammonia-lyase (PAL) activity, a key enzyme in the phenylpropanoid pathway, was decreased following infection. These results suggest that long-term bacterial disease stress may lead to down-regulation of select molecules of the phenylpropanoid metabolic pathway in strawberry leaves. This approach could be applied to explore the metabolic pathway associated with plant protection/breeding in strawberry leaves.
authors.affiliation: Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute , Seoul 120-140, Republic of Korea.
authors.forename: Min-Sun
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Busan Center, Korea Basic Science Institute , Busan 609-735, Republic of Korea.
authors.forename: Jong Sung
authors.initials: JS
authors.lastname: Jin
authors.affiliation: Department of Plant Medicine & RILS, Gyeongsang National University , Jinju 52828, Republic of Korea.
authors.forename: Youn-Sig
authors.initials: YS
authors.lastname: Kwak
authors.affiliation: Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute , Seoul 120-140, Republic of Korea.|Chemistry & Nanoscience, Ewha Womans University , Seoul 120-750, Republic of Korea.
authors.forename: Geum-Sook
authors.initials: GS
authors.lastname: Hwang
mesh_terms: D000146:Acids, Carbocyclic / Q000032:analysis; D060467:Disease Resistance; D005419:Flavonoids / Q000032:analysis; D031985:Fragaria / Q000378:metabolism* / Q000382:microbiology*; D005707:Gallic Acid / Q000032:analysis; D047348:Hydrolyzable Tannins / Q000032:analysis; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology*; D020156:Salicylic Acid / Q000032:analysis; D014974:Xanthomonas
chemical_list: D000146:Acids, Carbocyclic; D005419:Flavonoids; D047348:Hydrolyzable Tannins; D005707:Gallic Acid; D010650:Phenylalanine Ammonia-Lyase; D020156:Salicylic Acid
keywords: UPLC-QTOF/MS; bacterial angular leafspot; defense mechanism; metabolic profiling; strawberry leaves