APS Homepage

Oral: See the Unseen: Metatranscriptomics Unviels Plant and Vector-Pathogen Interactions


Transcriptomics of a downy mildew-spinach interaction.
R. ORNELAS (1), S. Klosterman (2), S. Koike (3), A. Hulse-Kemp (4), L. Derevnina (4), R. Michelmore (4), S. Reyes-Chin-Wo (4), K. Stoffel (4), A. Van Deynze (4) (1) California State University at Monterey Bay, U.S.A.; (2) United States Department of Agric

View Presentation

Downy mildew of spinach is caused by Peronospora effusa, an obligate, plant pathogenic oomycete, and is the most widespread and destructive disease of spinach in California and wherever spinach is grown. Symptomatic leaves display yellow lesions on otherwise dark green leaves, severely limiting their fresh market value. There is a lack of understanding of the susceptible and resistant genetic responses of the plant to P. effusa, and the genes that are differentially expressed in these two different interactions. In this study, the susceptible and resistant spinach cultivars, Viroflay and Solomon, respectively, were inoculated with P. effusa, and control plants were mock-inoculated. The expression of host and pathogen genes was evaluated using RNA sequencing to determine which genes are up- or down-regulated as a result of infection. Initial results revealed significant differences between treatments, including an abundance of plant defense-related genes that were differentially expressed. Additional analyses underway to uncover genes of P. effusa expressed in planta will be discussed. The results of this work are anticipated to provide insights into how this biotrophic pathogen infects the plant, how the plant responds genetically, and information useful to spinach breeders and pathologists.