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Enrico Bonello Assistant Professor |
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Research Interests
My background is in fungal tree pathology, molecular ecology of ectomycorrhizal fungi, and ecology of multi-party systems.
Pathogens are just one component of complex biological systems. Their direct interactions with their hosts and, indirectly via the host, other organisms, can have profound consequences on the dynamics of the ecosystem, be it natural or artificial, such as a forest plantation, a nursery, or an urban landscape situation, down to the front-yards and back-yards of homeowners. What is perceived as a negative effect or positive effect of disease depends on the context in which pathogens operate. In native environments, pathogens are an integral and often fundamental force in ecosystem dynamics and renewal, contributing to ecosystem biodiversity and long term stability and viability. In production contexts or in urban environments, both cases of highly simplified, and therefore unstable, ecosystems, diseases can have destructive consequences. Very often, diseases predispose trees to other negative forces, like insect pest attacks, which contribute to the eventual demise of the host tree. In Western North America alone, root disease/bark beetle complexes cause losses of around 6,000,000 m3 of timber/year. Other times, as with other plant-pathogen systems, disease may actually increase resistance to the same or other diseases or to insect attack. The outcome of the interaction depends on a multitude of complex factors.
As new faculty member I am responsible for the study of issues pertaining to the health of urban plants, with an emphasis on trees and shrubs. My overall interest lies in the factors that control the outcome of complex interactions among host trees, pathogens, beneficial microorganisms, such as mycorrhizal fungi, and destructive insects.
Research Plan
Systemic acquired resistance (SAR) is a well established phenomenon in crop plants. However, very little is known about SAR in trees. In recent work, I have established, for the first time, that SAR occurs in a conifer tree, Monterey pine, in response to a fungal pathogen, Fusarium circinatum, causal agent of pitch canker of pines. One of my projected interests at OSU will be to dissect this phenomenon at the biochemical and molecular levels. In the long run, this research may result in the development of environmentally sound, IPM-type methodologies for the control of tree diseases in urban environments as well as in tree nurseries.
Connected to this is my interest in the pathogen-induced systemic effects that render a diseased tree more attractive or palatable to phytophagous insects. In recent work I have identified a set of secondary metabolites that are induced systemically in root diseased pine trees. These compounds may be part of a cascade of metabolic events that may render diseased trees more palatable than non-diseased trees to insect pests. This work is still in its infancy, and at Ohio State I intend to continue in this direction, by concentrating on an important patho-system of pines in Ohio, Diplodia tip blight and canker, caused by the fungus Sphaeropsis sapinea. In this context, close collaborations with entomologists will be established. In the long run, these studies may lead to improved approaches to the control of fungal diseases and insect pests of amenity trees.
A third interest I have is to examine the ectomycorrhizal population and community structure of trees in an urban environment. This kind of work has been conducted successfully in natural environments, using molecular tools. Expanding these studies to urban settings will allow me to better understand the stressful factors involved in making urban plants more susceptible to disease. It may also allow for the discovery of improved approaches to enhance the mycorrhizal status of urban trees.
Selected References
- Bonello, P., Gordon, T.R. and A.J. Storer. Systemic acquired resistance in Monterey pine. Submitted to European Journal of Forest Pathology.
- Bonello, P., McNee, W., Storer, A.J., Wood, D.L. and T.R. Gordon. The role of olfactory stimuli in the location of weakened hosts by twig infesting Pityophthorus spp. (Coleoptera: Scolytidae). LEcological Entomology, accepted.
- Storer, A.J., Bonello, P., Wood, D.L. and Gordon, T.R. (1999). Evidence of resistance to the pitch canker pathogen (Fusarium circinatum) in native stands of Monterey pine (Pinus radiata). Forest Science 45, 500-505.
- Gordon, T.R., Wikler, K.R., Clark, S.L., Okamoto, D., Storer, A.J. and Bonello, P. 1998. Resistance to pitch canker disease, caused by Fusarium subglutinans f.sp. pini in Monterey pine (Pinus radiata). Plant Pathology 47: 706-711.
- Bonello, P., Bruns, T.D. and Gardes, M. Genetic structure of a natural population of the ectomycorrhizal fungus Suillus pungens (1998). New Phytologist 138 (4), 533-542.
- Storer, A.J., Wood, D.L., Gordon, T.R. , and Bonello, P. (1997) Current and future impacts of pitch canker disease of pines. Journal of Forestry 95, 21-26.
- Subbarao, K., Chassot, A., Gordon, T.R., Hubbard, J.C., Bonello, P., Mullin, R., Okamoto, D., Davis, R.M., and Koike, S.T. (1995). Genetic relationships and cross pathogenicities of Verticillium dahliae isolates from cauliflower and other crops. Phytopathology 85, 1105-1112.
- Bonello, P., Heller, W. and Sandermann, H. Jr. (1993). Ozone effects on root-disease susceptibility and defence responses in mycorrhizal and non-mycorrhizal Scots pine (Pinus sylvestris L.) seedlings. New Phytologist 124(4), 653-663.
- Bonello, P. and Pearce, R.B. (1993). Biochemical defence responses in primary roots of Scots pine challenged in vitro with Cylindrocarpon destructans. Plant Pathology 42, 203-211.
- Bonello, P., Pearce, R.B., Watt, F. and Grime, G.W. (1991). An induced papilla response in primary roots of Scots pine challenged in vitro with Cylindrocarpon destructans. Physiological and Molecular Plant Pathology 39, 213-228.
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