Home • Verticillium longisporum VL1
The image of Verticillium longisporum
Upper panel, left, microsclerotia on oilseed rape stem, c. 0.04 mm in diameter. right, microsclerotium formed on media plate. Lower panel, left, conidiophores formed on a media plate, right, spores, length c. 12 µm. [Image credit: Christina Dixelius]

The genome sequence and gene models of Verticillium longisporum VL1 were not determined by the Joint Genome Institute (JGI), but were downloaded from Ensembl Fungi on April 11, 2020. Please note that this copy of the genome is not maintained by Ensembl and is therefore not automatically updated. The JGI Annotation Pipeline was used to add additional functional annotation to the author's chromosomes and proteins.

The Verticillium genus belongs to the Plectosphaerellaceae family in the Sordariomycetes, one of the largest classes in Ascomycota. The genus name derives from the “verticilliate” morphological feature of the branched conidiophore, the hyphal structure that bears conidia. Verticillium longisporum substantially shares the disease cycle characteristics with the more studied V. dahliae. The species name “longisporum” refers to the close to twice as long conidia found in most strains in comparison to V. dahliae. V. longisporum causes stunting but not wilting in infected plants and the disease is now called Verticillium stem stripe. This soil-borne pathogen preferentially cause disease on plant species in Brassicaceae. 

A major problem is the longevity of its microsclerotia that are released into the soil from infected plant residues at the end of the disease cycle. These resting structures have the capacity to remain dormant in soil for many years. It is thought that the microsclerotia are stimulated to germinate via root exudates released from a host plant growing nearby. The hyphae then invade the lateral roots and root hairs followed by colonization of the root tissues and finally enter into the xylem elements. Next, conidia form and these spores can spread via the plant’s transpiration stream. Thus conidia are able to colonize vessel tissue further up in the plant, processes which could interfere with access to the xylem sap potentially affecting plant growth. Because the microsclerotia do not form and protrude stems and leaves until the plant is in the senescence phase, the disease easily remains unnoticed.

Genome Reference(s)