title: Comparative transcriptome analysis of the necrotrophic fungus Ascochyta rabiei during oxidative stress: insight for fungal survival in the host plant.
abstract: Localized cell death, known as the hypersensitive response (HR), is an important defense mechanism for neutralizing phytopathogens. The hallmark of the HR is an oxidative burst produced by the host plant. We aimed to identify genes of the necrotrophic chickpea blight fungus Ascochyta rabiei that are involved in counteracting oxidative stress. A subtractive cDNA library was constructed after menadione treatment, which resulted in the isolation of 128 unigenes. A reverse northern blot was used to compare transcript profiles after H(2)O(2), menadione and sodium nitroprusside treatments. A total of 70 unigenes were found to be upregulated by more than two-fold following menadione treatment at different time intervals. A large number of genes not previously associated with oxidative stress were identified, along with many stress-responsive genes. Differential expression patterns of several genes were validated by quantitative real-time PCR (qRT-PCR) and northern blotting. In planta qRT-PCR of several selected genes also showed differential expression patterns during infection and disease progression. These data shed light on the molecular responses of the phytopathogen A. rabiei to overcome oxidative and nitrosative stresses and advance the understanding of necrotrophic fungal pathogen survival mechanisms.
authors.affiliation: Plant Immunity Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India.
authors.forename: Kunal
authors.initials: K
authors.lastname: Singh
authors.forename: Shadab
authors.initials: S
authors.lastname: Nizam
authors.forename: Manisha
authors.initials: M
authors.lastname: Sinha
authors.forename: Praveen K
authors.initials: PK
authors.lastname: Verma
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics*; D001203:Ascomycota / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015152:Blotting, Northern; D017931:DNA Primers / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects* / Q000235:genetics; D015723:Gene Library; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D009599:Nitroprusside / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress / Q000502:physiology*; D057865:Plant Immunity / Q000502:physiology*; D010944:Plants / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction; D024483:Vitamin K 3 / Q000494:pharmacology
chemical_list: D017931:DNA Primers; D009599:Nitroprusside; D024483:Vitamin K 3; D006861:Hydrogen Peroxide