> Goals of Curriculum

Mission
The mission of our graduate program is to educate students in the science of plant pathology and prepare them to apply knowledge to diverse careers. The formal curriculum is designed to help students acquire excellence in research and to develop the breadth of skills required for successful careers.

Objectives
The objectives of the program are for students to attain and develop:

• excellence in research;
• breadth and depth in plant pathology;
• critical and analytical thinking skills;
• breadth in an allied field;
• strong communication skills;
• practical skills to prepare them for careers;
• thoughtfulness about their own education.

Areas of Proficiency in the major:
The discipline of plant pathology is directed toward understanding and solving disease problems of plants. The field is broad and complex, integrating disciplines as diverse as molecular biology and genetics, cell biology, organismal biology, ecology, meteorology, statistics, computer science, chemistry, and physics. The discipline of plant pathology encompasses basic and applied research, employs both model systems and economically important plants, and requires both laboratory and field experimentation. Plant pathologists interact with academic scientists, the grower community, private industry, and the general public. While no single plant pathologist is an expert in all of these aspects of the field, education in plant pathology should provide exposure to this breadth as well as depth in some aspects. Students should be sufficiently knowledgeable in all areas of plant pathology to identify key research questions, recognize significant discoveries, and think analytically about interpretation of data in each sub-discipline. Receiving a Ph.D. in plant pathology should indicate some level of proficiency in the areas described below. The level of proficiency in each area will vary with the student’s research area and career goals.

1. Etiology, diagnosis, and management of plant disease
Solving disease problems requires knowledge of their causes and principles of management. Effective disease management strategies are predicated on an accurate identification of the disease-causing agent and knowledge of the disease cycle, epidemiology, and host-pathogen interactions. A fundamental understanding of causes of disease and strategies for control provides a foundation for students who specialize in this area and a motivation and rationale for basic research in epidemiology, ecology, genetics, and physiology of plant-microbe interactions. Students should understand the principles of diagnosis, including the identification of signs and symptoms and the confirmation of a presumptive diagnosis with classical and modern methods; the demonstration of causality of disease; methods of disease management, including host resistance, chemical control, biological control, cultural methods; the principles of disease management, including considerations for how disease management strategies and crop management strategies interact.

2. Ecology and epidemiology
Ecology addresses the interactions of plant-associated microorganisms with their environments. The discipline involves study of how nutrient cycles and diseases mediated by microorganisms influence complex processes, such as succession and reproductive fitness in plant populations and communities. These processes are of interest both in natural and cultivated systems, and touch on important emerging concepts in biology, such as co-evolution. Plants also play critical roles in shaping population and community processes in the microbial world. These processes include migration, reproduction, and death on plant surfaces in response to chemical and physical factors.

Epidemiology is an applied aspect of ecology that focuses on the study of epidemics. Epidemiologists attempt to describe and predict how diseases progress in time and space. It is a quantitative sub-discipline of plant pathology that applies ecological principles to populations of plant pathogens and their hosts and to communities of organisms that interact with pathogens and their hosts in an attempt to understand spread of pathogens and disease progress. This area of plant pathology draws heavily on statistics, mathematical modeling, computer science, soil science, and meteorology. Students should be able to integrate biological principles of pathogen behavior with computations tools for analysis and modeling of populations and genes within those populations.

Students should be equipped to interpret research dealing with the following: the impact of the physical environment on pathogens and plant disease; role of energy flow and energy budgets in disease; measurement and control of physical environmental variables; measurement of disease and crop loss; mechanisms of pathogen transmission; multiplication of inoculum, dispersion of inoculum (e.g. for spores take-off, transport, deposition); infection (the biology that leads to our understanding of quantitative aspects of dose-response relationships); and methods of data collection (e.g. spore trapping). Students should acquire a basic knowledge of models used to quantify disease, population growth models and their limiting assumptions and usefulness. Students should be exposed to simulation modeling, able to work with simple models such as the logistic model, and be conversant in the statistical analysis of data fitted to models of that kind. In addition, students should be exposed to quantitative population genetic models. They should be able to think critically about deployment of resistance genes through breeding and genetic engineering, and about evolution of resistance to antimicrobial agents. They should have a thorough understanding of sampling issues related to spatial as well as temporal studies of disease progression. Students should understand the application of epidemiological and ecological principles to disease control, especially in the context of IPM and farming systems.

3. Genetics and physiology of plant-microbe interactions
Microbes and plants have developed complex and intriguing interactions to deal with or profit from their coexistence. Several of those mutualistic or antagonistic plant-microbe symbioses form the basis of cardinal processes in natural as well as in agricultural ecosystems and therefore have fundamental and applied importance. This sub-discipline of plant-microbe interactions involves the study of the biochemical and genetics mechanisms governing the establishment or prevention of those interactions. Research in this area aims to understand the signals and their transduction in both the plant and the microbe. This sub-discipline draws heavily on the allied fields of genetics, biochemistry, and cell biology.

In the plant, the focus is on the genes and gene products that control interactions with microbes. Mechanisms may involve chemical and structural, pre-formed and induced plant factors that are required for or prevent establishment of a relationship with a microbe. Signal transduction pathways and communication between the plant and the microbe are a key part of this field. Establishment of a relationship between a plant and a microbe may involve colonization, infection, nodulation, or systemic spread of a microbe in or on a plant. Research focuses on the local and systemic morphological and metabolic changes in the plant induced by infection or colonization by a microbe. In the microbe, the focus is on the mechanisms of survival and multiplication, host-detection, virulence factors, and elements that govern the maintenance and progression of the infection. Students should have an understanding of these concepts, approaches to their study, and how an understanding of the genetics and physiology of plant-microbe interactions will augment both our capacity to manage these interactions in agricultural settings and our knowledge of the biological world.

4. Organismal biology
In addition to the cross-cutting conceptual basis provided in Areas 1-3, students should have knowledge of the organisms that are partners in plant disease: viruses, bacteria, fungi, plants, and nematodes. The pathogens include viruses, prokaryotes, and eukaryotes, spanning all kingdoms of Life, and having simple to complex structures and life cycles, involving both sexual and asexual reproduction. Students should have a grasp of the diversity of pathogens and mutualists, approaches to study each organism group, and knowledge of the types of detriments and benefits to plant health derived from each type of microorganism. A knowledge of plant biology is key to plant pathology. Students should have some knowledge of plant anatomy, physiology, and genetics, and understand the role of plant responses in the disease process.

5. Critical Thinking Skills
The most important skill acquired in graduate school is the ability to think critically and analytically. These skills will be applied directly to the practice of science: choosing important problems to study, developing hypotheses, designing experiments, interpreting data, and placing experimental results in context. These skills are also essential for good teaching: critical evaluation of information and ideas is the first step in developing teaching materials. Analytical thinking is also key for the broader mission of being a scientist, including placing scientific findings in a societal context.

Analytical and critical thinking skills are developed through a wide range of activities in graduate school. It is the combination of experiences that helps students develop their own analytical styles. These experiences will include: planning a research project, interpreting data, reading the scientific literature. A key element in learning this process is writing and discussing writing about science.

It is our goal that all of our graduate courses will help students develop critical and analytical thinking skills in addition to providing exposure to subject matter. Students will also develop these skills in their research labs and with their mentors, in journal clubs and seminars, and in discussions of their written and oral presentations with their research committees.

6. Communication skills
Scientists must communicate. Clear, effective communication is essential to foster dialogue and education within the scientific community and between sciences and the rest of society. All students, regardless of their ultimate career goals, should become proficient in written and oral communication. Students are required to communicate with diverse audiences, including other students and members of the scientific community. While in graduate school, every student should find many and diverse opportunities for communication about science.

7. Professional development experience
The Ph.D. degree offers the highest level of training in critical and analytical thinking available in the U.S. education system. Graduates of the Ph.D. program will bring these thinking skills to bear on diverse problems in many settings. Some will build careers in the academic setting as faculty members at other research institutions. Others will conduct research in industry or government labs. Others will teach in colleges, high schools, or outreach settings. Some may use the Ph.D. as the basis for a career in science writing, law, or government policy. To help students obtain first-hand knowledge of career options and to enhance their training for their chosen careers, we offer students an optional professional development experience. Examples of such experiences are:

• apprenticeship to an Extension plant pathologist;
• intensive teaching beyond PP799 (in BioCore, MATC, Edgewood, high school);
• internship in industry (seed company, biotech company);
• internship in the media or government.

Any student who wishes to do an internship will be supported for up to three months on departmental funds unless the internship host offers financial support. Students looking for professional development opportunities should discuss possibilities with faculty and staff in the department. See the graduate program coordinator for a list of opportunities.

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