Valerie L. Wong
University of California, Berkeley
Department of Plant and Microbial Biology
321 Koshland Hall
Berkeley, CA 94720 USA

Molecular Mechanism of Symbiosis Cheating
The primary focus of my dissertation research is cheating of the ectomycorrhizal symbiosis, one of the most widespread mutualisms in terrestrial ecosystems. Mycoheterotrophic plants parasitize fungi by reversing the usual direction of net carbon flow in mycorrhizal interactions. Mycoheterotrophs thereby represent an extreme in the continuum of plant-fungal interactions within mycorrhizal symbioses. The tripartite symbiosis of photosynthetic plant – mycorrhizal fungus – nonphotosynthetic, mycoheterotrophic plant (Pinus – Rhizopogon salebrosus – Pterospora andromedea) provides a clear example of obligate cheating by a plant that evolved from photosynthetic mutualists. To investigate host specificity in establishment of the mycoheterotroph symbiosis by Pterospora andromedea, I am developing this as a model system that spans the extremes of mycorrhizal symbiosis from mutualism to parasitism.

Variation in a Global Population
Penicillium chrysogenum is a common, globally distributed species. I am interested in using high-throughput sequencing technology to identify genomic variations within this cosmopolitan fungus.
Rhizopogon Genome Project
The genus Rhizopogon includes over 200 described species with a worldwide distribution in natural and exotic pine forests. Rhizopogon salebrosus in particular also forms symbioses with the non-photosynthetic, mycoheterotrophic plant Pterospora andromedea (pine drops). This tripartite system between photosynthetic tree, mycorrhizal fungus, and non-photosynthetic plant is a simple mycorrhizal network. In collaboration with the DOE’s Joint Genome Institute, I am currently leading our lab’s efforts to sequence Rhizopogon salebrosus.

Publications and Presentations

Valerie L. Wong and Thomas D. Bruns. 2013. Gibberellic acid induces asymbiotic germination of the obligate mycoheterotroph Pterospora andromedea (Ericaceae). Madroño 60(3): 186-192.

Wong VL and Bruns TD. Enticing Mycorrhizal Parasitism: Inducing mycoheterotroph seed germination and transcriptional shifts in Rhizopogon. Selected Oral Presentation. International Mycological Congress. Edinburgh, Scotland. 2010. 

Wong VL and Bruns TD. Enticing Mycorrhizal Parasitism: Inducing mycoheterotroph seed germination and transcriptional shifts in Rhizopogon. Oral Presentation. Joint Meeting of the MSA and International Symposium on Fungal Endophytes of Grasses (ISFEG). Lexington, KY. 2010.

Wong VL and Bruns TD. Seduction of Mycorrhizal Fungi: Characterizing an Epiparasitic Model for Plant-Fungal Networks. Poster Presentation. Joint Meeting of the Mycological Society of America (MSA) and the Mycological Society of Japan (MSJ). Hilo, HI. 2005.

Stanford JS, Lieberman SL, Wong VL, Ruderman JV. Regulation of the G2/M transition in oocytes of Xenopus tropicalis. Dev Biol. 260(2):438-48. 2003.