Introduction to VertShield, an online community platform supporting research and control of Verticillium diseases.


Importance of Verticillium diseases

Verticillium is a group of plant pathogens that affect many different hosts worldwide, but are most common in temperate regions and occur infrequently in the subtropical and tropical regions of the world. The disease caused by Verticillium species is referred to as Verticillium wilt. Symptoms include wilting of the aerial parts of the plants, and discoloration of the vasculature of the root system. Verticillium longisporum also causes premature ripening and early senescence on oilseed rape (canola). Resulting economic losses commonly reach 50% or higher in cotton, lettuce, potato, strawberry and many other crops. Maple and other ornamentals can also be affected.

Pathology and known diversity of Verticillium species

Verticillium species are soilborne and infect their hosts through the root system. Disease progress is slow, and external symptoms are often absent until just before harvest. Also, Verticillium species can survive in the soil without a host as melanised resting structures for at least 14 years. This makes Verticillium wilt a very difficult and costly disease to manage once established. Ten Verticillium species have been described to date (Inderbitzin et al. 2011 PLoS One, 6(12): e28341). Verticillium dahliae is most economically important and probably infects hundreds of different hosts. The other species have narrower host ranges and more restricted global distributions, but they can still cause significant losses. A brief description and key characteristics of individual species can be found under Species Descriptions.

Why was VertShield built?

The main goal is to support the global Verticillium research community by providing quick and accurate means for identification of new isolates. This is achieved by accessing the genotypic and phenotypic characteristics archived in VertShield. The archive currently contains DNA sequences of seven phylogenetically informative loci from 281 isolates representing all 10 Verticillium species, including all type strains, as well as seven isolates of Gibellulopsis nigrescens, an outgroup species used for phylogenetic analyses (Inderbitzin et al. 2011 PLoS One, 6(12): e28341). A BLAST function is provided for sequence-based identification of new strains, and a user guide for sequence-based identification can be found at Sequence Based Identification. Additional reference materials, such as protocols and technical guides, are also available to facilitate research on Verticillium species. We hope that the resources and tools available at VertShield will serve as a global community platform that supports knowledge preservation and sharing and will also foster the development of new control strategies against this important group of fungal plant pathogens.

Acknowledgements

This project has been mainly supported by a USDA-SCRI grant (2010-51181-21069). A training grant from the USDA-NIFA Agriculture and Food Research Initiative Competitive Grants Program (2010-65110-20488) supported Bongsoo Park, a graduate student who participated in building VertShield. Seogchan Kang acknowledges Penn State Institute for CyberScience Faculty Fellowship. We would like to thank those who have generously contributed materials and information to VertShield.

Contact us

Dr. Seogchan Kang at sxk55@psu.edu for technical questions/problems in using VertShield, suggestions for its improvement, and data contribution.
Dr. Patrik Inderbitzin at prin@ucdavis.edu for questions concerning the identification of Verticillium species.
Dr. Krishnamurthy Subbarao at kvsubbarao@ucdavis.edu for any other types of questions.