USDA-ARS-AFRS

2217 Wiltshire Road

Kearneysville, WV 25430

Voice: (304) 725-3451 x210

Professional Biographical Information:

Education:

1991:         Ph.D. Plant Physiology, Texas A&M University, College Station, TX

1983:         B.S.   Cornell University, Ithaca, N.Y.

1981:         A.S.   Community College of the Finger Lakes, Canandaigua, N.Y.

Professional Experience:

2004-present     USDA-ARS, Appalachian Fruit Research Station, Plant Physiologist

1996-2004                    USDA-ARS, Appalachian Fruit Research Station, Microbiologist

1994-1996                    USDA-ARS, Appalachian Fruit Research Station, Postdoctoral Scientist       

1992-1994                    Cornell University, Postdoctoral Scientist

Research Projects and Activities:

There are two main research activities that I am engaged in, directly contributing to the accomplishment of ARS Strategic Goal #1, Enhancing Economic Opportunities for Agricultural Producers.  The first is managing the Apple Biotechnology Group.  The group is responsible for transforming apple with various constructs for scientists within the CRIS entitled ‘Using Functional and Applied Genomics to Improve Stress and Disease Resistance in Fruit Trees’ (CRIS 1931-21220-014-00D, National Program 302).  The transformed lines are used for investigative or proof-of-concept purposes such as developing ‘cleaner’ transgenic technologies.  Such technologies are also geared towards enhancing the protection and safety of the nation’s agriculture and food supply (ARS Strategic Goal 3) by mitigating concerns regarding the commercial use of genetically enhanced fruit crops. 

The second area is investigating how fruit trees, primarily apple and peach, respond to biotic and abiotic environmental stresses.  Biotic stresses are those arising from biological sources such as insects, herbivores, as well as fungal and bacterial pathogens.  Abiotic stresses arise from sub- or supra-optimal amounts of some critical non-biotic input such as water (drought or flooding), temperature (too high or too low, including early and late frosts), and nutrients and minerals (insufficient or excess quantities).  My particular interest is in the genes and the products they encode that are either induced or repressed in response to abiotic environmental stresses, particularly low temperature and water deficit (drought).  Gene products can be broadly classified as either regulatory or functional.  Regulatory gene products include transcription factors, and control the expression of other genes.  They are typically in some regulatory pathway or network, and frequently integrate the various signals, external and internal, that a plant perceives, and direct the plant to respond to the signal.  Functional proteins include enzymes, and carry out some task in the cell such as removing aberrantly folded proteins that could seriously impair the cell’s ability to function.  

One class of functional proteins, termed dehydrins, have received much attention due to their unusual biochemical properties and their tendency to accumulate in response to dehydration, salinity, and low temperatures.  Originally coined from “dehydration induced” protein, dehydrins are boiling stable, and are found in every plant examined to date, and in most tissues, including seeds.  Secondary structure predictions indicate that dehydrins could form an amphipathic α-helix, which has been proposed to interact with and stabilize proteins or membranes.  Low water status reduces the hydration of biomolecules such as proteins, which can lead their denaturation and to the disruption of membranes.  Dehydrins have been proposed to ameliorate these consequences by reducing hydrophobic aggregations or inappropriate interactions.  While their specific function is yet to be demonstrated, several genetic studies have indicated a role in water deficit or cold tolerance.  Research performed at this location was the first to demonstrate that dehydrins are seasonally regulated in peach (Prunus persica [L.] Batsch) bark, reaching a maximum in transcript and protein accumulation in autumn through early spring, and that transcriptional and translational regulation are critical components to the accumulation of dehydrins.  Parallel work showed that seasonal regulation is also the case in a number of other woody plant species.  More recent research has examined the expression patterns of differentially regulated dehydrins to better understand cold acclimation of peach trees.     

Research Accomplishments:

·         Establishment of the first bark cDNA library at the Appalachian Fruit Research Station.

·         Characterization of two seasonal- and cold-regulated dehydrin genes.

·         First report of alternative splicing in the ethylene receptor ETR1.

·         Establishment of a novel water deficit treatment regimen.

·         Establishment of novel cold and photoperiod treatments to separate dormancy and cold acclimation events

·         First staff member to create transgenic yeast to expressing a potential biocontrol protein.

·         Implementation of PCR-based library screening methods at the Appalachian Fruit Research Station.

·         Responsible for a significant increase in transgenic apple trees lines at the Appalachian Fruit Research Station.

·         Introduction of degenerate and mutagenic PCR-based techniques at the Appalachian Fruit Research Station.