Frank N. Martin was born in Salinas, CA. He received his bachelors in Botany from the University of California, Berkeley in 1977 with an independent study project in the lab of Dr. Joe Hancock, which led to working one year as a technician prior to starting graduate school. He received his M.S. (1981) and Ph.D. (1984) in Plant Pathology from UC-Berkeley. After a brief postdoctoral appointment with Dr. Jim Duffus of the USDA-ARS in Salinas, CA he started a faculty position at the University of Florida in 1985. In 1995, he moved back to his hometown by accepting a Research Plant Pathologist position with the USDA-ARS in Salinas, CA. Martin has been an APS member since 1980 and has served APS as: a) Associate Editor (1994-1996, 2001- 2002) and Senior Editor (2003-2005) of Phytopathology, b) organizer of APS workshop and symposium, and c) member or chair of five committees. Dr. Martin has been an exceptional mentor to many young scientists, guiding them to their future careers in academia, industry or government.
Dr. Martin has contributed to enhancing preparedness against oomycete pathogens by improving understanding of the diversity and ecology of oomycetes, generating critical data and tools needed in detecting and identifying oomycete plant pathogens, and empowering global stakeholders in managing Phytophthora pathogens. He provided critical knowledge and protocols via online platforms and as co-chair/instructor of the International Workshop for the Morphological and Molecular Identification of the Stramenopiles Phytophthora and Pythium for the five times it has been held.
Dr. Martin established a robust phylogenetic framework for Pythium, Phytophthora, and related genera that enables reliable detection and accurate identification of pathogens. This framework is also critical for understanding the evolution of important traits such as adaption to particular ecological habitats, morphological features, plant/animal pathogenicity, obligate/facultative pathogenicity, and host range. In addition, placing the ecological niches and geographical distribution pattern of individual pathogens in the phylogenetic context is critical for investigating likely mechanisms underlying pathogen movement and variation. His research on this topic started with Pythium by demonstrating the utility of the mitochondrial (mt) cox2 locus as a phylogenetic maker at a time when only the nuclear internal transcribed spacer (ITS) region of ribosomal RNA encoding genes was used. He expanded the use of mt sequences for oomycete phylogenetic analysis by applying cox2 and other mt loci to Phytophthora. Genus-wide phylogenetic analysis of Phytophthora based on both mt and nuclear loci resulted in a comprehensive phylogenetic framework that played an essential role in the discovery and description of novel species and pathogens.
Applying the data and insights from his phylogenetic work, Martin developed mt DNA-associated RFLP as a tool for rapid identification of Pythium and Phytophthora species. More recent work with Phytophthora includes: a) enhancing specificity of PCR-based diagnostic assays based on unique mt gene order; b) generating mt sequence data for over 1,200 isolates representing 145 taxa for developing species specific diagnostic assays; c) validating a genus-specific TaqMan assay that provides a systematic approach for developing species specific probes; in silico analysis supports probe development for 89% of the genus (50 species-specific probes have been validated, most of which are on the APHIS species of concern list, to provide the regulatory agency with tools to prevent introduction); and d) developing an isothermal assay that allows detection in the field in as little as 15 minutes without the need for DNA extraction. The isothermal assay is genus-specific with species-specific detection for nine species. Through a collaborative project he has shown that these isothermal assays can provide immediate information to growers.
To support phylogenetic analyses, diagnostic tool development, and studies on oomycete evolution, Martin assembled the mt genomes of a wide range of oomycete taxa (550 genomes representing 145 taxa). He is using the resulting data to: a) study the evolution of the mt genome; b) identify and apply mitochondrial haplotype markers for population genetic analysis; c) design highly conserved primers for amplification of loci that provide a hierarchical approach for metagenomic studies; and d) provide a systematic approach for development of diagnostic assays for Pythium and Aphanomyces based on gene order differences and by identification of unique sequences for several species of downy mildew.
Data provided by Martin were instrumental in building and improving the Phytophthora Database (http://www.phytophthoradb.org), an online platform developed to support accurate and rapid identification of Phytophthora species and to coordinate the discovery and cataloging of novel taxa. This sequence database currently houses 6,315 sequences from 1 to 12 loci of 2,623 isolates (representing 123 described and 23 provisionally named species) and has supported strain identification and diagnostic tool development by researchers around the world. In 2015, it was utilized ~1,500 times per month and accessed from more than 50 countries. His contributions include: a) mt gene sequences and curation of archived sequence data to correct historical errors; b) creation of most species description pages; and c) writing a comprehensive review of available molecular diagnostics tools and sequence alignments used for developing PCR-based diagnostics tools.
Martin has also worked as part of a team investigating alternative strategies to methyl bromide preplant soil fumigation for controlling soilborne pathogens in strawberry production. A notable contribution to this area of research was using remote sensing to evaluate efficacy of alternative control measures on a field-wide basis. He has also worked on several soilborne pathogens of strawberry, including Pythium, binucleate Rhizoctonia spp., and more recently Macrophomina phaseolina and Fusarium oxysporum f. sp. fragariae. Additional research projects include investigating the phylogenetic relationships among R. solani AG2-2 isolates recovered from sugar beet and development of SSR markers for conducting population studies. He has presented 10 invited research presentations in special sessions at APS meetings and has written 13 reviews or book chapters, which disseminate knowledge on Phytophthora and Pythium.
