Module Identifier BS32020  
Academic Year 2001/2002  
Co-ordinator Dr Luis Mur  
Semester Semester 2  
Other staff Dr Gareth Griffith, Dr Ian Scott  
Course delivery Lecture   30 Hours  
  Seminar   1 Hours 1 x 1 hours  
Assessment Practical exercise   Continuous assessment of practicals   20%  
  Exam   3 Hours One 3-hour theory paper   80%  
  Resit assessment   3 Hours One 3-hour theory paper (plus resubmission of failed coursework or an alternative)   80%  

Aims and objectives

The course will be designed to provide a multidisciplinary introduction to plant pathology. Due stress will be paid both to the mechanisms underlying pathogenic attack or insect grazing and on the host-response.   We will concentrate on model interactions that are the object of considerable research allowing the student to use ?up-to-the minute? sources of information. The programme will conclude with a consideration of how this scientific knowledge is being applied to reduce crop losses.


With pathogen and insects interactions we will be examining mutually antagonistic scenarios, where in response to various methods of challenge, plant have been developed complex counter-measures.

Virulence Mechanisms
Due to the intrinsic variation in plant structure and biochemistry as well as the need to avoid plant anti-microbial responses, plant pathogens have evolved very different 'virulence' mechanisms allowing them to exploit a plant host. This theme will be explored in a series of 'keynote' lectures describing pathogens which have emerged as major research models.
(i) An overview of fungal pathogenesis
(ii) Blumeria graminis: a biotrophic fungus.
(iii) Erwinia caratovora: and Pseudomonas syringae as bacterial pathogens
(iv) Agrobacterium sp.: tumour-inducing bacterial pathogens.
(v) Tobacco Mosaic Virus (TMV), focusing on the processes underlying viral infection, replication and movement.

Plant Responses to pathogens
Plant responses to pathogenic challenge will focus on resistance associated with the hypersensitive response (HR). Key events discussed will include, the plants anti-microbial recognition, and subsequent signalling events leading to the generation of free-radicals ('the oxidative burst'), programmed cell death leading to defence gene expression. Following the HR, plants display a systemic acquired resistance (SAR) to further infection.   The exhibition of SAR has been shown to be absolutely dependent on salicylic acid (SA). The role of SA in conferring SAR, together with its modes of action and biosynthesis will be discussed.

Combating the effects of insect attack   
Insect grazing obviously elicits a wound response but in addition insect anti-feedants such as hexanals and the subsequent expression of proteinase inhibitors (PI) are induced. Each will be considered and the chemical signalling pathways based on 'wound-signal' jasmonic acid will be examined in some detail. The production by the wounded plant of gaseous signals to attract insect parasitoids will also be examined.   

The application of biotechnology
Many biotechnological companies have aiming to increase field-resistance to pathogens and insects using methods that will be outlined in this section of the course.

A 'Plant Pathogenicity' workshop will allow infected plants to be examined and interpreted.

Learning outcomes

On completion of the module the student will

? appreciate how various approaches in microscopy, biochemistry and genetics are applied to increase scientific knowledge
? have developed 'fact-finding' skills by being encouraged to consult primary sources of information to supplement the lectures.

Reading Lists

** Recommended Text
Gurr, S.J.. (1992) Molecular plant pathology : a practical approach. Blackwell Science.
Lucas, J.A.. (1998) plant pathology and plant pathogens. 3rd. Blackwell Science.
** Multiple Copies In Hugh Owen
Issac, S.. (1992) Fungal-plant interactions. Chapman Hall.
Agrios, G.N.. (1997) Plant Pathoglogy. 4th. Academic Press.