PATH 8400

HOST-PATHOGEN INTERACTIONS

GENERAL COURSE INFORMATION

Instructor:
Dr. Tim Denny Office: Room 3303 Plant Science Bldg.
tdenny@uga.edu 542-1282

Class Schedule:
We meet Tuesdays and Thursdays 3rd period (11:00 a.m.-12:15 p.m.) in Room 2102 Plant Science Building. Class time is a mix of lecture and discussion. Anyone who wishes can attend and participate in the lectures (bring your friends!). A proposed lecture schedule is provided on a separate sheet.

Course Overview:
This course focuses almost entirely on the interactions of plants and pathogens during pathogenesis. The emphasis is at the molecular level, drawing heavily on the disciplines of genetics, biochemistry, molecular biology, and cell biology. Several of the mutualistic and antagonistic interactions illustrate broader principles and contribute to our fundamental understanding of biological processes. The outcome of the these interactions have a strong impact on agricultural productivity, and so are also of applied importance.

Establishment of a relationship between a plant and a microorganism may involve colonization, infection, nodulation, or systemic spread of a microbe in or on a plant. In the microbe, our focus will be on the mechanisms of host detection, colonization/multiplication, virulence, and the maintenance of the infection. Microbial signals that alter host physiology and morphology will be examined. In the plant, our focus will be on the genes, gene products and biochemical events that control plant-microbe interactions. We are especially interested in plant perception of microbial signals, plant signal transduction pathways and associated local and systemic defense mechanisms. We will also consider the potential of genetically altered plants to improve agriculture, and the social and ethical issues of this approach.

Course Objectives:
Present a conceptual and factual framework of host-microbe interactions
Examine selected examples of current research on host-pathogen interactions.
Encourage critical analysis of terms, concepts and scientific literature.
Foster conjecture regarding the cellular and molecular aspects of host-pathogen interactions.

Course Mechanics:
Text:
There is no assigned textbook for this course. A list of relevant books will be provided separately. Although now going out of date, the single best text is still Molecular Plant Pathology edited by M. Dickinson and J. Benyon (2000, CRC Press OR 2003, BIOS Scientific). It is available from Amazon.com for less than $60. This book reviews most aspects of the material covered in this course. Selected books may be placed on reserve at the UGA Science Library; you will be notified if this occurs.

Supplemental Reading:
Copies of the articles that you are expected to read and be familiar with will be provided via WebCT or as hard copies in Room 2108. (Remember that the copying machine in the Plant Pathology office is NOT to be used for class material). For the hard copies of articles there will be two sets: One in a 3-ring binder that should not circulate outside of the lab or the plant pathology conference room; Another in manila folders that you can take with you to another site for several hours or overnight after ~9:00 p.m. Please be considerate of other students when taking these materials and return them as quickly as possible.

Grant Proposal:
Each student will write scientific research grant proposal on a question relevant to host-microbe interactions. Details regarding preparation of the proposals will be provided separately early in the semester. Students will select topics of interest to them (in consultation with the instructor), and a written ÔoutlineÕ must be approved by the instructor before the indicated date. As part of the preparation process, each student will write a constructive review of one draft proposal and later a critical review of one proposal as if they were a member of a grant review panel. These reviews will constitute part of your grade, not the grade of the students whose proposals you are reviewing; the instructor will assign the final grade to the proposals. Written components of this project that are not handed in on time will be docked one letter grade per day for the first two days; after this a student will receive no points for that component.

Exams:
There will be a mid-term and final exam. About a week before each exam, students will be given a short list of essay questions, some of which will appear on the test (instructorÕs choice). You can prepare for the exam using any resource, including other students, but the tests will be written from memory during the exam period. If a student has a legitimate reason for missing the exam period, then a make-up time will be arranged.

Student Responsibilities:
You are expected to attend class regularly, keep up with assigned readings, and contribute to class discussions. I encourage you to ask questions during or after class. Most importantly, I want you to THINK about the course material! Your attendance and general participation in the class constitutes a small amount of your final grade.

All academic work must meet the standards contained in "A Culture of Honesty." Students are responsible for informing themselves about those standards before performing any academic work (for more detailed information go to: http://www.uga.edu/ovpi/honesty/acadhon.htm).

Grading
General participation 5%
Midterm exam 25%
Research proposal 25% (5% on draft, 20% on final version)
Proposal reviews 10% (5% for each)
Final exam 35%
Total 100%

Important Dates
2/28 MIDTERM EXAM
3/2 Semester midpoint (3/7 - Midpoint withdrawal deadline)
3/9 Grant proposal topic and outline must be approved by this date
4/4 Proposal draft due to reviewer and instructor
4/11 Proposal review due to author and instructor
4/24 Final revised proposals due
5/1 Final review of proposals due to the instructor
5/9 12:00 p.m. FINAL EXAM (I might reschedule)

Proposed Course Schedule

Day Date Topic
1 1/10 L1: Course introduction, key concepts and terms, leaf and plant cell wall structure
2 1/12 L1 continued
3 1/17 L2: Introduction to bacterial plant pathogens
4 1/19 L3: Ralstonia solanacearum : a model bacterial pathogen
5 1/24 L4: Agrobacterium tumefaciens : molecular pathogenesis and plant transformation
6 1/26 L5: Two-way communication in Rhizobium -plant interactions
7 1/31 L6: Plant cell wall degrading enzymes in disease
8 2/2 L7: Phytoanticipins Ð preexisting defense mechanisms
9 2/7 L8A: Introduction to plant pathogenic viruses (Deom)
10 2/9 L8B: Current research in plant pathogenic viruses (Deom)
11 2/14 L9A: Introduction to fungal plant pathogens (Gold)
12 2/16 L9B: Current research with Ustilago maydis , the corn smut pathogen (Gold)
13 2/21 L10: Introduction to plant path nematodes and current molecular research (Hussey)
14 2/23 L11: Hrp gene clusters and type III protein secretion by bacteria
15 2/28 MIDTERM EXAM (covers through 2/23)
18 3/2 L12: Elicitors and PR proteins
16 3/7 L13: The gene-for-gene hypothesis and secreted effector molecules
17 3/9 L13 continued (Grant Proposal Topic Approved BY TODAY)
Spring Break, 3/13-17
19 3/21      L14: Activities of pathogenic fungi outside the host (prepenetration and penetration)
20 3/23 L14 continued

21 3/28 L15: Phytotoxins Ð structure, mode of action, and roles in pathogenesis
22 3/30 L16: Plant resistance genes and signal transduction pathways
23 4/4 L16 continued (Proposal draft due to reviewer and instructor)

24 4/6 L17: Defense signal transduction, programed cell death, HR, and active oxygen
25 4/11 L17 continued (Proposal review due to author and instructor)

26 4/13 L18: Induced resistance - local and systemic
27 4/18 L18 continued
28 4/20 L19: Induced defenses Ð phytoalexins, cell wall appositions, etc.
4/24 Final revised proposals due

29 4/25 L20: Converting knowledge of pathogenesis into methods of disease control
30 4/27 Class discussion: Social and ethical issues of using transgenic plants for disease control
5/1 Final review of proposals due to instructor

5/2 Question and answer/review session (optional)
5/9 Noon to 3:00 p.m. FINAL EXAM (may try to reschedule for before May 6)

This course syllabus is a general plan for the course; deviations announced to the class by the instructor may be necessary.