Submitted to: Fungal Genetics Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/11/2012
Publication Date: 3/12/2013
Citation: Duressa, D., Anchieta, A.G., Chen, D., Klimes, A., Dobinson, K.F., Garcia-Pedrajas, M., Klosterman, S.J. 2013. RNA-seq analyses of gene expression in the microsclerotia of Verticillium dahliae. Fungal Genetics Conference Proceedings. p. 194. Interpretive Summary:
Technical Abstract: Verticillium dahliae is a soilborne fungus that causes wilt disease in plants. Verticillium wilt is difficult to control because the pathogen is capable of persisting in the soil for 10 to15 years as melanized microsclerotia, rendering crop rotation strategies for the control of this disease ineffective. The microsclerotia of V. dahliae produce infectious hyphae that give rise to primary infections. As such, the processes of microsclerotia formation, maintenance, and germination are critically important in the disease cycle of V. dahliae. To shed additional light on the molecular processes involved in microsclerotia biogenesis and melanin synthesis in V. dahliae, three replicate RNA-seq libraries were prepared from 10 day-old microsclerotia (MS)-producing cultures of V. dahliae (ave=52.23 million reads), and those not producing microsclerotia (NoMS, ave=50.58 million reads), and analyzed for differential gene expression. The comparisons revealed up-regulation of MS library genes involved in melanogenesis, including tetrahydroxynaphthalene reductase (344-fold increase) and scytalone dehydratase (231-fold increase), and of additional genes located in a 48.8 kilobase melanin biosynthetic cluster. Numerous hypothetical protein-encoding genes were also identified as differentially expressed in the MS library. For confirmation of differential expression, selected genes identified by RNA-seq as up- or down-regulated were analyzed by RT-qPCR of RNA from several MS and NoMs culture types, including MS cultures that were stored for 6 months at 4°C, and seven day old cultures having an intermediate number of melanized MS. These data provide further insight into gene expression during melanin biosynthesis and MS formation in V. dahliae, and the products encoded by these genes may represent alternative disease control targets.