How does nutritional status affect plant immunity and disease? (Ref: CTPFCR20193)

This student is to be registered with University of Reading and will be mainly based at NIAB EMR, Kent. The team of supervisors will be led by Dr Richard Harrison of NIAB EMR.

It is well established from field studies that application of excessive nitrogen can lead to weak growth and enhanced susceptibility to a range of pathogens, especially necrotrophic pathogens. The enhanced disease susceptibility is often attributed to physical alterations in rapidly developing tissues, e.g. micro-cracks in plant stems. However, there is an increasing body of evidence that suggests that nitrogen status directly affects the ability of pathogens to infect the plant. This studentship will examine whether there is evidence for this phenomenon in the Rosaceae, specifically strawberry and apple.

This studentship will examine two potential hypotheses, by which both foliar and root pathogens may modulate plant immunity and disease:
1. N-related gene expression can be directly affected by pathogen infection.
2. Nitrogen status alters plant immune responses and thus the plant’s response to pathogens.

The most important eligibility criterion for this funded studentship is residency:

• UK students: If you have been ordinarily resident in the UK for three years you will normally be entitled to apply for a full studentship, covering tuition fees and a maintenance stipend.
• EU students: If you have been ordinarily resident in another EU country (outside the UK) for three years you will normally be able to apply for a tuition fees-only award (without a maintenance stipend). If you have lived in the UK for three years you may be eligible for a full studentship.

This eligibility is unaffected by Brexit. The UK Government has guaranteed EU eligibility for Research Council funding for PhDs beginning before the end of the 2019-20 academic year.

Anyone interested should contact [Email Address Removed] for application form and return the form to [Email Address Removed] before the deadline of 30th April 2019

Background

It is well established from field studies that application of excessive nitrogen can lead to weak growth and enhanced susceptibility to a range of pathogens, especially necrotrophic pathogens. The enhanced disease susceptibility is often attributed to physical alterations in rapidly developing tissues, e.g. micro-cracks in plant stems. However, there is an increasing body of evidence that suggests that nitrogen status directly affects the ability of pathogens to infect the plant. For example glutamine synthetase encoding genes have been shown to be induced following infection. In response to necrotrophic pathogens and pathogens triggering resistance, more N metabolism genes are differentially regulated, suggesting that pathogens target N metabolism directly. This studentship will examine whether there is evidence for this phenomenon in the Rosaceae, specifically strawberry and apple.

Objectives

This studentship will examine two potential hypotheses, by which both foliar and root pathogens may modulate plant immunity and disease:
1. N-related gene expression can be directly affected by pathogen infection.
2. Nitrogen status alters plant immune responses and thus the plant’s response to pathogens.

Approaches

The research work will be divided into four workpackages (WPs), each with clear deliverables.
WP1: Developing a robust assay to study alterations in N metabolism through tagging of N-responsive reporter genes
WP2: Tagging and localisation of key immune system markers in foliar and root tissues
WP3: Assessing cross-talk between N-sensing and immune signalling upon infection with biotrophic pathogens
WP4: Assessing cross-talk between N-sensing and immune signalling upon infection with necrotrophic pathogens

Benefit to the industry

Given the key importance of both accurate fertilizer rates and resistance to pests and diseases, this studentship will explore the effect of N (NO3) levels on both responses to biotrophic pathogens and necrotrophic pathogens, using highly controlled growth studies in both apple and strawberry. Using a range of molecular techniques, key genes involved in both plant immunity and N regulation will be studies under these conditions, to test the three possibilities outlined above. This will provide a student with training in both plant nutrition and molecular biology, spearheading the development of this understudied area of perennial crop biology.