Gwybodaeth Modiwlau

The course will be designed to provide a multidisciplinary introduction to plant pathology and insect herbivory. We will concentrate on model interactions which currently are the object of considerable research allowing the student to use "up-to-the minute" sources of information. The module will not be simply describing a given interaction but examining the molecular determinants underlying each example studied. Two workshops will aim to refine the students' data interpretative skills.

With pathogen and insects interactions we will be examining both methods used to exploit plants together with the plants response and deployment of 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. We will, in turn, examine fungi, bacteria and viruses as plant pathogens in each case focusing on representative pathogens which have emerged as major research models.

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 and 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 using will activate a range of responses including the induction of such anti-feedant genes as proteinase inhibitors (PI) and the production of toxic chemicals e.g. hexanol/ols and isocyanates. Additionally, plants produce gaseous signals to attract insect parasitoids and predators - thereby establishing tritophic interactions. Each aspect of the plant response will be discussed - highlighting how these are tailored to a particular insect or group of insects. A particular focus will be on the role of octadecanoids, particularly jasmonates, in the anti-insect response.

Workshops
Two workshops will be run during this module where the onus will be placed on developing data-interpretative skills. One workshop will focus on fungal interactions with cereals whilst the second will focus on Tobacco Mosaic Virus (TMV) and bacterial pathogens of tobacco.