PARENT SESSION
Poster Session #62: Parasite-Host Interactions.
Thursday, August 8. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC

Epichloë glyceriae infection and carbon translocation in the grass Glyceria striata.

PAN, JEAN^*,1, CLAY, KEITH¹, ¹ INDIANA UNIVERSITY, BLOOMINGTON, IN

ABSTRACT- Physiological integration, or resource translocation, is the movement of resources such as carbon or nitrogen, from one part of a clonal plant to another part. Resource translocation between parent and daughter ramets has been shown to be important for ramet establishment and survivorship. Changes in resource translocation patterns may affect clonal growth patterns and ramet establishment. In a previous study, we showed that infection by the fungus Epichloë glyceriae causes greater clonal growth in its host Glyceria striata. Because Epichloë relies completely on Glyceria for resouces, fungal infection is likely to alter resource translocation and lead to changes in clonal growth patterns. To test this hypothesis, we labeled infected and disinfected plants with ¹⁴C and compared the growth of stolons with (intact) and without (severed) resource translocation. We found that infected and disinfected plants had similar patterns of carbon movement, with most of the carbon being retained in the labeled leaf. Basipetal carbon movement was generally limited to the section closest to the labeled leaf, while apical movement proceeded to the tip of the stolon. There were also no differences in stolon growth of intact and severed stolons. In summary, we found no evidence that fungal infection changed carbon movement in host plants. These data suggest that changes in carbon sink dynamics was not responsible for differences in host growth pattern and that Epichloë infection was not a substantial carbon drain on host plants.

KEY WORDS: clonal plants, symbiosis, Epichloë , plant-fungal interaction