The Genome Sequence of the Fungal Pathogen Fusarium virguliforme That Causes Sudden Death Syndrome in Soybean

Fusarium virguliforme causes sudden death syndrome (SDS) of soybean, a disease of serious concern throughout most of the soybean producing regions of the world. Despite the global importance, little is known about the pathogenesis mechanisms of F. virguliforme. Thus, we applied Next-Generation DNA Sequencing to reveal the draft F. virguliforme genome sequence and identified putative pathogenicity genes to facilitate discovering the mechanisms used by the pathogen to cause this disease

Excision of an Active CACTA-Like Transposable Element From DFR2 Causes Variegated Flowers in Soybean [Glycine max (L.) Merr.]

Active endogenous transposable elements, useful tools for gene isolation, have not been reported from any legume species. An active transposable element was suggested to reside in the W4 locus that governs flower color in soybean. Through biochemical and molecular analyses of several revertants of the w4-m allele, we have shown that the W4 locus encodes dihydroflavonol-4-reductase 2 (DFR2). w4-m has arisen through insertion of Tgm9, a 20,548-bp CACTA-like transposable element, into the second intron of DFR2. Tgm9 showed high nucleic acid sequence identity to Tgmt*. Its 5′ and 3′ terminal inverted repeats start with conserved CACTA sequence. The 3′ subterminal region is highly repetitive. Tgm9 carries TNP1- and TNP2-like transposase genes that are expressed in the mutable line, T322 (w4-m). The element excises at a high frequency from both somatic and germinal tissues. Following excision, reinsertions of Tgm9 into the DFR2 promoter generated novel stable alleles, w4-dp (dilute purple flowers) and w4-p (pale flowers). We hypothesize that the element is fractured during transposition, and truncated versions of the element in new insertion sites cause stable mutations. The highly active endogenous transposon, Tgm9, should facilitate genomics studies specifically that relate to legume biology

Heat-map depicting the Pfam domains in all <i>Fusarium</i> species.

<p><i>F. virguliforme</i> genome is rich in Pkinase_Tyr (Protein tyrosine kinase), Ank (Ankyrin repeat), and HET (Heterokaryon incompatibility proteins) as compared to the other <i>Fusarium</i> genomes.</p

Phylogenetic tree showing the relationship of <i>F. virguliforme</i> with other <i>Fusarium</i> species.

<p>The tree was constructed using 10 randomly selected single copy orthologous genes using PHYML program (WAG model of evolution) with 1,000 bootstraps.</p

General assembly statistics of the draft <i>Fusarium virguliforme</i> genome.

<p>General assembly statistics of the draft <i>Fusarium virguliforme</i> genome.</p

Synteny of <i>Fusarium virguliforme</i> Mont1 sequences to the <i>Nectria haematococca</i> chromosomal sequences.

<p>The colored blocks show the alignment of <i>F. virguliforme</i> sequences to the sequences of the <i>N. haematococca</i> chromosomes. Blocks below the central line indicate the regions that align in the reverse complement orientation.</p