Professor, Department of Plant Sciences

2228 PES
amberry@ucdavis.edu
(530) 752-7683 office

Education

B.A. (magna cum laude) in Anthropology, Radcliffe College, 1970
M.S. in Botany, University of Massachusetts, 1978
Ph.D. in Botany, University of Massachusetts, 1983 

Research Interests

My current research effort is focused largely on nitrogen-fixing plants, primarily trees and shrubs nodulated by the soil actinomycete, Frankia (for example Alnus, Ceanothus, Cercocarpus, Purshia), but also including some legumes.

1. Assessment of the role and mechanism of nitrogen-fixing plants in N accretion in semiarid ecosystems and agroecosystems.

Nitrogen-fixing root nodule symbioses can facilitate restoration of disturbed sites following fire, landslide, or anthropogenic disturbance, by increasing soil nitrogen and carbon. We are following the flux of nitrogen from fixers to non-fixers in a semiarid ecosystem in southwestern Colorado, using several experimental approaches. We are currently also synthesizing the results from a 3-year project studying nitrogen fluxes in almond orchards with legumes used as cover-crops.

2. Plant-microbe interactions in symbiotic biological nitrogen fixation.

Ongoing research in my laboratory is concerned with plant-microbe interactions during nodulation and nitrogen fixation. Rhizosphere signals important for nodulation have not been characterized in actinorhizal plants, and I continue to examine the effects of flavonoid compounds on patterns of nodulation by Frankia. We have already characterized a number of temporal and spatial patterns of nodule-enhanced plant gene expression, and I anticipate continuing work at the level of gene expression, both of the host and Frankia.

Oxygen is a key environmental factor regulating nitrogen fixation which I have studied from a biochemical and developmental standpoint. I continue to investigate the molecular basis of oxygen regulation in Frankia. Obtaining gene sequence information for Frankia is a priority, to enhance future research possibilities.

Awards, Honors, Elections

Program Director, National Science Foundation 1998-1999
Visiting Professor, Stockholm University, Sweden, 1997 (fall)
Visiting Professor, University of Lyon, France, 1996 (spring)
National Merit Scholar, 1966-1970