Contact information:

517-355-4573
sundin@msu.edu    

Education:

B.S. Penn State University
M.S. Michigan State University
Ph.D. Oklahoma State University
Postdoc University of Illinois-Chicago

General areas of expertise:

Plant bacteriology, host-pathogen interactions, bacterial plasmids, fruit tree disease management, phyllosphere microbial ecology

Overview of current program:

We work with two main bacterial plant pathogens, Erwinia amylovora, causal agent of fire blight of apple and pear and Pseudomonas syringae. Our work with E. amylovora is focused on developing a comprehensive understanding of the fire blight interaction at the molecular level. Thus, we perform genetic analyses of the pathogen to identify and characterize key genes involved in virulence and we also study the genetic response of apples to fire blight infection and are searching for genes involved in disease resistance. We back our molecular laboratory studies with field studies to ensure that our findings are applicable to field conditions.

Our work with Pseudomonas syringae is focused on studying the pPT23A plasmid family. In 1998, my group, along with collaborators in Spain, determined that almost all P. syringae strains carry a one or multiple plasmids that form a related group. These plasmids encode virulence genes, other genes important for ecological fitness, bactericide resistance genes, as well as genes important for plasmid transfer between strains. We are interested in understanding the evolutionary history of this plasmid family as well as understanding the role that these plasmids play in the transfer of important genetic information among divergent P. syringae strains.

My group is also actively involved in work aimed at the management of important diseases of fruit trees in Michigan including fire blight and bacterial canker of cherry, and important fungal diseases such as apple scab, cherry leaf spot, and brown rot. Some of this work involves surveys of bactericide resistance and fungicide resistance as it is important to know which current materials will still effectively control diseases. Where resistance problems have emerged, we are also actively engaged in working to find alternative disease control measures.

Students interested in my program can work on disease genetics, genomics, proteomics, etc. and/or can work on determining more immediate solutions to disease problems. My group is dynamic, varied in interests and experience, but focused on solving problems and scientific advancement.

Publications:

Fire blight:

Zhao, Y., S.E. Blumer, and G.W. Sundin. 2005. Identification of Erwinia amylovora genes induced during infection of immature pear tissue. Journal of Bacteriology 187:8088-8103.

Foster, G.C., G.C. McGhee, A.L. Jones, and G.W. Sundin. 2004. Nucleotide sequence, genetic organization, and distribution of pEU30 and pEL60 from Erwinia amylovora. Applied and Environmental Microbiology 70:7539-7544.

Maxson-Stein, K., G.C. McGhee, J.J. Smith, A.L. Jones, and G.W. Sundin. 2003. Genetic analysis of a pathogenic Erwinia sp. isolated from pear in Japan. Phytopathology 93:1393-1399.

Pseudomonas syringae plasmid biology:

Zhao, Y., Z. Ma, and G.W. Sundin. 2005. Comparative genomic analysis of the pPT23A plasmid family of Pseudomonas syringae. Journal of Bacteriology 187:2113-2126.

Sundin, G.W., C.T. Mayfield, Y.F. Zhao, T.S. Gunasekera, G.C. Foster, and M. Ullrich. 2004. Complete nucleotide sequence and analysis of pPSR1 (72,601 bp), a pPT23A family plasmid from Pseudomonas syringae pv. syringae A2. Molecular Genetics and Genomics 270:462-476.

Fruit tree disease management:

Proffer, T.J., R. Berardi, Z. Ma, J.E. Nugent, G.R. Ehret, P.S. McManus, A.L. Jones, and G.W. Sundin. 2006. Occurrence, distribution, and PCR-based detection of resistance to sterol demethylation inhibitor fungicides in populations of Blumeriella jaapii in Michigan. Phytopathology 96:709-717.

Ma, Z., T.J. Proffer, J.L. Jacobs, and G.W. Sundin. 2006. Overexpression of the 14-demethylase target gene (CYP51) mediates fungicide resistance in Blumeriella jaapii. Applied and Environmental Microbiology 72:2581-2585.

Phyllosphere microbial ecology:

Gunasekera, T.S., and G.W. Sundin. 2006. Role of nucleotide excision repair and photoreactivation in the solar UVB radiation survival of Pseudomonas syringae pv. syringae B728a. Journal of Applied Microbiology 100:1073-1083.

Jacobs, J.L., T.L. Carroll, and G.W. Sundin. 2005. The role of pigmentation, ultraviolet radiation tolerance, and leaf colonization strategies in the epiphytic survival of phyllosphere bacteria. Microbial Ecology 49:104-113.

Extension and outreach activities:

The goals of my Extension program are to provide timely information and recommendations on management of diseases of fruit trees to growers in Michigan and other fruit-growing regions. I am achieving these goals through a number of ways including performing applied laboratory and field research on important bacterial and fungal diseases and their control that generates information that can be translated directly to growers. These results are then disseminated directly to fruit tree growers through Extension presentations at various winter meetings throughout Michigan and at local meetings during the growing season, radio interviews, and also through newsletter articles such as those appearing in the MSU-IPM Fruit CAT Alert weekly bulletin. I also provide disease control recommendations in the MSU Fruit Management Guide, and these recommendations are updated yearly.