Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

This project will establish the science underpinning our recent discovery that soaking seeds of plants in plant defence hormones confers long-lasting pest resistance in plants grown from these seeds. It will investigate the fundamental mechanisms behind priming of defence against pests and diseases by seed treatments with jasmonic acid (JA) and the nonprotein amino acid, beta-aminobutyric acid (BABA). The primary objectives are: 1. To determine the extent to which JA and BABA seed treatments directly stimulate defence even without any biotic attack, and the extent to which they act via priming. This objective will be achieved by investigating (i) transcriptional profiles, and (ii) profiles of volatile emissions, in control and seed-treated plants before and after pest attack. 2. To examine the contribution of chromatin remodelling and DNA methylation to the priming of defence-related genes in seed-treated plants. 3. To investigate the impacts of seed treatments with JA and BABA on (i) direct defences against herbivores, (ii) indirect defences against herbivores, and (iii) pathogen resistance. 4. To test the hypothesis that JA and BABA act independently, providing additive (or even synergistic) effects on defence when used as a combined seed treatment. The project will generate data relating to plant responses to JA and BABA seed treatments at three levels: gene expression, volatile emission and susceptibility to insect attack. Molecular and biochemical changes will be compared between primed and un-primed plants with and without subsequent infestation by insects. Insect bioassays will put the observed changes in gene expression and volatile emission in an ecological context, both in terms of interactions with herbivores and in terms of tritrophic interactions with natural enemies of the herbivores.

Research in this project is focused on the movement ecology and spatial patterning of populations of pests (insects & pathogens) and beneficials (natural enemies & pollinators). Many pests and their natural enemies are highly mobile (which affects their ability to colonise and damage crops), while the quantity and quality of seed and fruit production in many crops is dependent on the spatial structuring of the crop and the movement patterns of pollinators. This project seeks to tackle all aspects of spatial scaling from national and regional dynamics through to landscape and farm-scale patterns and individual movements, in an attempt to better understand how sustainable food production and high levels of biodiversity can co-exist in agricultural landscapes. The research tackles the following questions: 1. Are invasive species and their migration pathways predictable, and can models be developed that elucidate a mechanistic understanding of observed spatial patterns of pests? 2. Do pest species exhibit spatial synchrony over large scales, and does this synchrony facilitate area-wide suppression given additional management interventions? 3. At what scale should pests, pathogens and natural enemies be managed (monitored and controlled) for maximum yield? 4. Does the spatial patterning of floral resources of differing nutritional quality affect the search strategies, foraging success, colony fitness and pollination services of bees? 5. How do sub-lethal infections of diseases and parasites affect the navigational capabilities, foraging success, and fitness of infected versus uninfected hives? These questions will be tackled with a variety of approaches, including exploitation of Rothamsted’s long-term datasets and classical experiments; purpose-built entomological radars for studying long-range migration and short-range foraging movements; and mathematical models to predict and explain spatio-temporal dynamics in pest and beneficial populations.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

There is concern about the potential impact of climate change on the diversity of the UK flora and the fauna it supports. It is likely that the increasing temperatures, changing rainfall patterns and increased likelihood of extreme events predicted by Global Climate Models (GCMs) will alter the current distribution of indigenous plant species and may provide opportunities for non-indigenous plants to invade. The conventional approach to predicting these changes has been to combine species distribution models (based on current habitat range) with GCMs to model the shift in the bioclimatic envelope. However, the species assembly that ultimately occupies a locality will also depend on local conditions, land management and biotic interactions. All of these drivers are likely to respond to climate change and, if the resulting shift in plant functional diversity is to be predicted, they all need to be included in the analysis within a simulation framework based on climate change scenarios predicted for a selected region. Because an extensive literature on the eco-physiology of weeds and their response to the environment and management already exists, arable plant communities are an ideal model system for addressing this fundamental research challenge. We will combine a process based eco-physiological model of weed population dynamics and competition with a stochastic weather generator to predict the shift in the realised niche of indigenous UK arable plants and the potential for non-indigenous species to invade on a regional scale. In addition, the ability of species to adapt and the potential shift in plant functional diversity will be predicted using data on intra and inter specific variability in plant functional traits. The approaches and principles developed in the proposal will be instrumental in improving the predictive understanding and manipulation of plant communities in a range of habitats under climate change including grassland systems.