Project description:Verticillium nonalfalfae is a fungal plant pathogen that causes wilt disease by colonizing the vascular tissues of host plants. The disease induced by hop isolates of V. nonalfalfae manifests in two different forms, ranging from mild symptoms to complete plant dieback, caused by mild and lethal pathotypes, respectively. Pathogenicity variations between the causal strains have been attributed to differences in genomic sequences and perhaps also to differences in their mitochondrial genomes. We used data from our recent Illumina NGS-based project of genome sequencing V. nonalfalfae to study the mitochondrial genomes of its different strains. The aim of the research was to prepare a V. nonalfalfae reference mitochondrial genome and to determine its phylogenetic placement in the fungal kingdom. The resulting 26,139 bp circular DNA molecule contains a full complement of the 14 "standard" fungal mitochondrial protein-coding genes of the electron transport chain and ATP synthase subunits, together with a small rRNA subunit, a large rRNA subunit, which contains ribosomal protein S3 encoded within a type IA-intron and 26 tRNAs. Phylogenetic analysis of this mitochondrial genome placed it in the Verticillium spp. lineage in the Glomerellales group, which is also supported by previous phylogenetic studies based on nuclear markers. The clustering with the closely related Verticillium dahliae mitochondrial genome showed a very conserved synteny and a high sequence similarity. Two distinguishing mitochondrial genome features were also found-a potential long non-coding RNA (orf414) contained only in the Verticillium spp. of the fungal kingdom, and a specific fragment length polymorphism observed only in V. dahliae and V. nubilum of all the Verticillium spp., thus showing potential as a species specific biomarker.
Project description:MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are short (19â25 nucleotides) non-coding RNA molecules that have large-scale regulatory effects on development and on stress responses in plants.The objective of this study is to investigate the transcriptional profile of miRNAs and other small non-coding RNAs in Verticilliumâinoculated cotton roots. Four small RNA libraries were constructed from mocked and infected roots of two cotton cultured species which are with different Verticillium tolerance (âHai-7124â, Gossypium barbadense L., a Verticillium-tolerant cultivar, and âYi-11â, Gossypium hirsutum L. a Verticillium-sensitive cultivar). The length distribution of obtained small RNA pools was significantly different among libraries. A total of 215 conserved miRNA families were identified in the two cotton species, of them 14 are novel. There were >65 families with different expression between two libraries. We also identified two ta-siRNAs and thousands of endogenous siRNA candidates, and hundred of them exhibited altered expression after inoculation of Verticillium. The profiling of these miRNAs and other small non-coding RNAs lay the foundation for further understanding of small RNAs function in the regulation of Verticillium defence responses in cotton roots.
Project description:Identification of genes differentially expressed in roots of Arabidopsis Col-0 and ndr1-1 mutants 48 h post inoculation with the fungal pathogen Verticillium longisporum.