Crucifer’s Pathogens Genome

Abstract

The information on genome sequences, analysis and assembly of limited pathogens of crucifers has been generated and made available. It has given deeper insight into the molecular and biological functions of host–pathogen interactions in different ecological situations in nature and directed in the modern agricultural operations. The Albugo candida genome size is 45.3 Mb which is significantly smaller than a comparable biotrophs, Hyaloperonospora arabidopsidis. A. candida genome is deficient in enzymes required for nitrate and sulfate assimilation and has a reduced number of cell wall degrading enzymes. It has low number (26) of RXLR effector-like genes. Alternaria brassicae genome assembly consists of 17 contigs of 34.14 Mb sequences. The contigs ranges in length from 66.7 to 7.01 Mb. Of the 17 contigs, 1 represents the mitochondrial genome. The assembly contains nine complete chromosomes. The Colletotrichum higginsianum genome is 53.4 Mb in size and distributed among 12 chromosomes including two mini-chromosomes less than 1 Mb. The fungi causing powdery mildew disease has about four times larger genome size than those of other ascomycetes. The genome of G. orontii is 160 Mb in size. The fungi Fusarium oxysporum genome is 57.3 Mb in size with 583 scaffolds. The G:C content is 47.4%. The genome analysis of Hyaloperonospora has revealed phylogeny of H. parasitica with other species infecting cruciferous genera and species along with major species clusters in it. The final version of H. arabidopsidis genome of Emoy 2 isolates assembly consists of 81.6 Mb (V8.3.2) comprising of 42% of the Hpa genome. The genome assemblies for two isolates of H. brassicae differing for their virulence comprise of genome size of 72.762 and 76.950 Mb and 6470 and 6470 scaffolds. Leptosphaeria maculans genome is 45 Mb in size and organized in an unused patchwork fashion with G:C rich blocks known as isochore structure. There is reduction in intergenic space with multiple overlapping un-translated regions (UTRS) in L. maculans. Plasmodiophora brassicae genome is compact and small in size of 24.2–25.5 Mb with high gene density. Thirteen chitin syntheses gene have been identified. The white stem rot pathogen Sclerotinia sclerotiorum genome is 38.3 Mb in size and contains 679 sequence contigs giving 8X sequencing coverage of the genome. A complete assembly of S. sclerotiorum genome contains an additional 80S, 146 bp. It produces a number of extracellular pectin–degrading enzymes and biosyntheses genes of phytotoxins and other secondary metabolites. Bacterium Xanthomonas campestris comprises circular chromosomes of approximately 5,000,000 base pairs (bp), have a high G + C content and do not carry plasmids. Genome-wide comparisons have revealed three secretion system (type I, III, IV) associated with pathogenesis. The genome of Turnip Mosaic Virus (TuMV) isolates are 9798 nt in length, few are one to three nucleotide shorter in the terminal UTR’s. Genome sequencing, comparative genome, transcriptome and secretome analysis of pathogenic species, clades and isolates facilitates determination of phylogeny, host specificity, pathogenicity factors/genes, evolution period, clonal reproduction, genetic exchange, and molecular genetical mechanisms and events in all host-pathosystem.