Ignacio Chapela

eESPM


Ignacio Chapela Associate Professor Ph.D. 334 Hilgard Hall Berkeley, California 94720 ichapela@nature.berkeley.edu office: 510-643-2452 lab: 510-643-2452 fax: 510-643-5098 Web site Recent publications People


Research Interests With at least 6 fungal species for each species of plant in a given environment, fungi represent one of the major components of terrestrial ecosystems. Their biomass can outweigh that of any other component, and their roles range from the control of nutrient cycling (e.g. in the regulation of green-house gases), to their indispensable role as symbionts of practically all other forms of life. However, this vast world remains practically uncharted. My research delves into this realm to explore questions such as: Where are fungal individuals in nature? How do they relate to each other? How do they relate to other organisms, particularly plants and arthropods? Epic tales of battle, companionship and long-lasting relationships are common fare in this field. In contrast with some other areas in biology, Mycology, the study of the fungal world, must still investigate case studies from first principles, developing each one into single "historietas" or "storylets", just as Nineteenth-Century naturalists did. However, modern techniques, and suitable concepts developed for other systems, make this process much faster, so that these "historietas" can become compatible with our quickly evolving understanding of life. Understanding is not the only goal of this research. Fungi are possibly the most under-used biological resource available to promote a balanced, sustained human development that could counter current trends of species and habitat loss. In Mycology, therefore, research can be readily linked to social and economic needs, as in the cases of bioprospecting for novel armaceuticals and agrochemicals for human use, development of biocontrol agents, and the sustainable management of forests through understanding and use of their fungal components. I am involved in the research and development of these connections between the academic, industrial and civil worlds across international borders, particularly in Latin America.
Current Projects One model of my interest is the symbiosis between leaf-cutter ants and their cultivated fungi (the attine symbiosis). Recent results indicate that this system contains "historietas" which can be linked up to provide information on the evolution and maintenance of symbiotic systems. More primitive representatives of the attine symbiosis must continuously re-capture fungi over ecological time to cultivate and eat in their nests, while derived representatives have "domesticated" a single lineage of fungi for over 30 million years. These fungus-ant chimaeras are probably the single most important nutrient processor in the Neotropics (up to 30% biomass is processed by leaf-cutters) as well as a major agricultural pest. Using molecular and physiological tests in the laboratory as well as field research, my lab is actively engaged in understanding the consequences of this symbiosis (e.g. the origin and evolution of clonality, the adaptive radiation caused by new configurations of life), as well as looking for potential means of manipulating it. Fungi and plants are associated in a myriad of symbiotic relationships. One of the least studied is that between most healthy, living aerial organs of plants and so-called endophytic fungi. We are studying the stories of two contrasting groups of endophytes: Lophodermium spp and their pine hosts, and Hypoxylon spp. who inhabit oaks. We are addressing questions such as: how faitful is the relationships between these organisms? When do they bailout on their "friendly" interaction to become pathogenic? Can we discern evolutionary trends from looking at the current distribution of extant groups over biogeographical scales? Plantation of exotic tree species is currently championed as a main response to global "Greenhouse warming". Plantation trees, it is believed, have the capacity to take up and fix atmospheric CO2, a main greenhouse gas. However, little attention is being paid to the mycological dimension of this land-use change. We are studying the ecophysiological behaviour of fungi in plantations, and are finding that they might be crucial in deciding whether the promise of exotic plantations is fulfilled or not. This research involves descriptive and experimental work in native and out-planted situations, currently in California (native Monterey Pine) and Ecuador (introduced plantations). An ongoing collaborative project with local indigenous communities in Southern Mexico is the focal point of an investigation into questions of sustainable management of highly diverse, delicate environments. Fungi are a hub in this project, as they are bringing out complementary sources of revenue, interest and concern for these local communities, as well as providing sensitive criteria for conservation, management decisions and business planning. Questions being addressed include: Who is the owner of natural resources? How can property rights to land/resources affect conservation and sustainable management efforts? What systems of valuation can be applied to natural resources in the age of cost-benefit analysis? How can local communities, who can have the right and willingness to either preserve or plunder, be effectively included in transactions on biodiversity in the age of globalization?
Recent publications Palm, M.A, and Chapela, I.H. 1997. Mycology in Sustainable Development: Emergent Concepts, Vanishing Borders. Parkway Publishers, Boone, NC. Chapela, I.H., Rehner, S.A., Schultz, T.R. & Mueller, U.G. 1994. Evolutionary history of the symbiosis between fungus-growing Ants and their Fungi. Science, 266(5191): 1691-1694. Chapela, I.H. 1994. Bioprospecting in the information age: a critical analysis of pharmaceutical searches through biodiversity. In: J. Feinsilver (ed.) Emerging Connections: Biodiversity, Biotechnology and Sustainable Development. Panamerican Health Organization/Interamerican Institute for Cooperation in Agriculture. Washington, DC. In press. Chapela, I.H. & Feinsilver, J. 1994. Conclusions. In: J. Feinsilver (ed.) Emerging Connections: Biodiversity, Biotechnology and Sustainable Development. Panamerican Health Organization/Interamerican Institute for Cooperation in Agriculture. Washington, DC. In press. Stone, J.K., Viret, O., Petrini, O. and Chapela, I.H. 1994. Histological studies of host penetration and colonization by endophytic fungi. In: Host Wall Alterations by Parasitic Fungi (ed. by Orlando Petrini and Guillemond Ouellette). APS Press, St. Paul MN. Dreyfuss, M.M. & Chapela, I.H. 1994. Fungi as producers of secondary metabolites. In V.P. Gullo (ed.) Discovery of natural products with therapeutic potential. In press. Chapela, I.H., Petrini, O. & Hagmann, L.H. 1991. Monolignol glucosides as specific recognition messengers in fungus-plant symbioses. Physiological and Molecular Plant Pathology 39:289-298.
Recent Teaching
6 - Environmental Biology
90 - INTRO TO CRS
H196 - HONORS RESEARCH
299 - INDIVIDUAL RESEARCH