- Work Address:
- Department of Plant Biology
- 321 Koshland Hall
- University of California
- Berkeley California 94720
- (510) 643-5483
- email: nhynson@nature.berkeley.edu
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Nicole joined the Bruns lab in September of 2004. On May 10 2007, Nicole successfully passed her PhD qualifying exam.
Nicole's current research interests include mycorrhizal ecology, the importance of fungal networks in the evolution of myco-heterotrophic and mixotrophic plants and the use of stable isotopes as food-web tracers. While the relationship between most plants and mycorrhizal fungi is mutually beneficial, some plants have evolved to cheat this symbiosis; these plants are known as myco-heterotrophs and have lost the ability to photosynthesize. Myco-heterotrophic plants act as a carbon sink, tapping into carbon assimilated by trees via shared mycorrhizal fungi and thus avoid light competition with neighboring plants. Myco-heterotrophy has been observed in more than 400 species and 87 genera world-wide, particularly in genera well adapted to low-light habitats. While myco-heterotrophy is one of the longest studied aspects of the mycorrhizal symbiosis there remain many fundamental questions regarding the ecology, evolution and physiology of these intriguing plants.
Recently it has been shown that some green plants exploit their symbiosis with mycorrhizal fungi to fulfill their carbon demands. Since they have diverged from a fully autotrophic lifestyle these plants are referred to as mixotrophs. The triggers for mixotrophy are poorly understood. The extent of mixotrophy, its role in forest floor food-webs, and impacts on plant community assemblages remain to be elucidated, and is currently the subject of much debate. It has been proposed that environmental conditions such as light and the presence of particular mycorrhizal fungi may play key roles in the mixotrophic abilities of some plants. If mixotrophy is a widely distributed adaptation in understory plants this would fundamentally change our current understanding of the role of fungal networks in plant competition and above ground community structure.
To elucidate the ecology and evolution of both myco-heterotrophic and mixotrophic plants Nicole has chosen to focus her research on the plant tribe the Pyroleae (Ericaceae). This group contains closely related taxa that occupy different ecological niches along the autotrophy-mixotrophy-myco-heterotrophy continuum. Furthermore, the tribe contains a single putative myco-heterotrophic taxon, the rare non-photosynthetic Pyrola aphylla, this species appears to be recently derived from photosynthetic ancestors. Nicole's field sites are located throughout the northern Sierra and southern Cascade mountain ranges, but she works primarily at UC Berkeley’s Blodgett Research Forest.
Nicole's laboratory work integrates two fundamentally different methods to examine mixotrophic and myco-heterotrophic plant ecology: DNA sequence analysis and the use of stable isotopes as food-web tracers. Due to the lack of identifying morphological features of Pyroleae mycorrhizae, there has been little information on the fungi associated with these plants. Using nucleotide sequencing she is able to identify the mycorrhizal fungi of Pyroloids and examine patterns of specificity in the putative myco-heterotrophic taxon, P. aphylla. In collaboration with researchers at the University of Bayreuth, Germany, they are using the stable isotopes of carbon and nitrogen to test for mixotrophy and myco-heterotrophy in the Pyroleae.
When not in the lab Nicole can be found either in the woods hunting mushrooms, somewhere in the Pacific getting pounded by waves on her surfboard (she's a native of Maui), or studying yoga (she's been a practitioner for some 20 years now!). Her past and current collaborators include researchers from Dr. Gerhard Gebauer’s lab in Bayreuth Germany, Dr. Martin Bidartondo at Kew Royal Botanical Gardens UK, Diana Jolles of Ohio State University and Sir David Read of University of Sheffield, UK. She's enthusiastic about teaching and has been a Graduate Student Instructor for two upper division biology courses at Berkeley: the Diversity of Plants and Fungi, and California Mushrooms. For more information please consult her CV or contact her directly via e-mail.
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