U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Molecular Plant Pathology Laboratory: Beltsville, MD
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Databases
                        Alfalfa Transcription Factor Database
                                    iPhyClassifier - Phytoplasma Sequence ClassificationSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Northeast Area Beltsville, Maryland (BARC) Beltsville Agricultural Research Center Molecular Plant Pathology Laboratory Docs





- About
- Achievements and Awards
- Publications
- Spiroplasma Kunkeliigenome Sequencing Project
- Genbank Submissions
- Endopeptidase Alignment of Various Phytoplasmas
- Spiroplasma kunkelli Plasmid

Dr. Robert E. Davis Legacyheadline bar Robert E. Davis Phytoplasmas (mycoplasmalike organisms, MLOs) and spiroplasmas are plant pathogenic, cell wall-less bacteria that underwent massive reductions in genome size during their evolution from walled bacterial ancestors. Thus, these unusual microbes possess genomes that are among the smallest known in bacteria, approaching the minimal sets of genes required for cellular life and parasitism in plants and insects. The loss of genetic material over evolutionary time was accompanied by the gain of new capabilities enhancing host adaptation and conferring potentials for pathogenicity in insect vectors and plant hosts. Dr. Davis' areas of research interest in phytoplasmas and spiroplasmas were: Genomic events leading to evolutionary emergence of a new life form-phytoplasmas
Gene degradation and the loss of biosynthetic pathways that resulted in small genomes and obligate intracellular life styles
Expansion of functions carried out by genes that were retained through evolution
Acquisition of genes encoding new functions that enabled host adaptations and pathogenicity in insects and plants
Transfer of virulence factors throughextrachromosomal DNA
Identification of pathogen proteins as potential targets for new, safe disease control measures
Molecular markers of genus and species level evolutionary divergence
Detection,classification,identification, andtaxonomyof phytoplasmas in unsolved diseases  Through his research, we gained new fundamental understandings of the evolutionary emergence ofspiroplasmasand phytoplasmas, which provided molecular markers and tools for improving detection and identification of the pathogens. Diseases studied include; grapevine yellows,corn stunt The results of Dr. Daivs' research helps to: Predict their pathogenic potentials
Improve pathogen detection and molecular taxonomy of wall-less bacteria
Target pathogen proteins for molecular disease control
Enhance implementation of quarantine measures and aid disease management.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov