Award details

Modelling and manipulation of plant-aphid interactions: A new avenue for sustainable disease management of an important crop in Africa

ReferenceBB/J01138X/1
Principal Investigator / Supervisor Professor Toby Bruce
Co-Investigators /
Co-Supervisors
Institution Rothamsted Research
DepartmentBiological Chemistry & Crop Protection
Funding typeResearch
Value (£) 56,495
StatusCompleted
TypeResearch Grant
Start date 01/09/2012
End date 31/08/2016
Duration48 months

Abstract

Our overall objective is to assess potential risks/benefits for disease management (using epidemiological modelling with experimental validation) from identifying and adapting the knowledge/tools (including gene sequences/semiochemicals/epidemiological models) from studying viral suppressor of RNA silencing-mediated effects on aphid-plant relations to develop 'push-pull'-type systems to protect bean. However, aphids are important pests and disease vectors affecting all major crops, meaning our results will have wide applicability. Our collaboration will translate work from model systems (Arabidopsis and tobacco) to a vital crop (bean) with uniquely African viral disease problems (with emphasis the combined effects of bean common mosaic virus and bean common necrotic mosaic). Key objectives/activities are listed with lead researcher(s) and time-scales indicated in parentheses. 1. Epidemiological modelling (Yrs 1-4, CAG, Cam) 2. Validation and exploration of modelling predictions in controlled conditions (Yrs 1-4, Cam) 3. Field surveys and data collection in Uganda (Yr. 1) and experiments utilizing data from 1 and 2, and field samples (Yrs. 2-4)(MA, CIAT) 4. Analyzing the effects of silencing suppressors on bean mRNA and small RNA profiles (Yrs 2-4) (JH, AD, BecA; DB, Cam) 5. Metabolite analyses to identify semiochemicals produced by bean that influence plant-aphid interactions (Yrs 2-4, Rothamsted) 6. Initiating pathways to impact activities via the Pan-Africa Bean Research Alliance, a network of the national bean research programmes of 28 African nations (Yr3/4; Lead: MA, CIAT).

Summary

In Eastern and Central Africa beans are a vital crop because they enrich the soil with fixed nitrogen (an indispensable natural fertilizer), which in turn supports the cultivation of other important crops such as corn (maize) and cassava. Beans are an essential part of the regional diet because they are rich in protein and crucially important micronutrients like iron and zinc. Since beans are predominantly grown and traded by women, this crop provides additional direct economic benefits to women and their children. Unfortunately, a number of viruses attack bean plants, causing severe crop losses from disease. Although there are a few bean varieties with resistance to one of these viruses (called bean common mosaic virus), a closely related virus that occurs widely in, and is indigenous to, Africa (bean common necrotic mosaic virus) causes plants of these 'resistant' lines to die. Thus, it is important to develop new strategies to defend this vital crop. Our approach is to attack the insects (aphids) that transmit these viruses from plant to plant. We have found that aphid-plant interactions are controlled in large part by the plant's 'small RNA pathways'. Small RNA pathways are a recently discovered regulatory system used by plants and many other organisms to control the expression of their own genes as well as to fight off disease. The discovery of small RNA pathways has revolutionized biology and medicine. In plants, small RNA pathways control, among other things, the production of natural signal chemicals that attract or repel insect pests, including aphids. Intriguingly, viruses produce factors called 'silencing suppressors' that modify small RNA pathways. We have found that silencing suppressors affect the interactions of virus-infected plants with aphids in a way that is likely to enhance the rate at which these insects acquire viruses and transport them to other plants. We have assembled a team of scientists based in Uganda, Kenya and at two centres in the UK to translate these findings from the laboratory to the field and exploit them for protection of beans. However, aphids and the viruses they transmit are problems for all major crops and the work will yield vital data for the wider field of crop protection. Our multinational team will collaborate to: A. Identify potential factors involved in mediating plant-aphid communication in plants: small RNAs, the genes they control, and the chemical signals whose production they regulate. B. Use the modelling methods provided by the discipline of mathematical epidemiology to help us design experiments (under lab and later field conditions) to predict how altering the attractiveness of plants (whether engendered by changes in the plant or deployment of signal chemicals as traps or decoys) could be used to help minimize or prevent the transmission of viruses. C. Utilize the work from 1 and 2 to design experiments to test the effects on virus transmission of modifying plant responses to aphids or utilization of purified signal chemicals to trap or deter aphids under controlled and simulated field conditions. D. To achieve impact by disseminating information gained from our work to African crop scientists, growers and consumers through the Pan-Africa Bean Research Alliance, a network of the national bean research programmes of 28 African nations.

Impact Summary

We aim to develop technologies for aphid management (and potentially other insect pests) and aphid-vectored viruses while strengthening capacity in sustainable pest and disease management. Transnational, multi-stakeholder and participatory approaches ensure technology uptake and provide opportunities for beneficiaries along the value chain (incl. research papers, epidemiological models, gene sequences and markers for bean improvement through PABRA's networks, semiochemicals that could be exploited by growers, industry, etc). Cambridge Plant Sciences hosts a Business Fellow (Beatrix Schlarb-Ridley) to facilitate routes to impact and the Dept. is the hub of the Cambridge Partnership for Plant Sciences linking many research institutes, SMEs and regional industry. The Figure summarizes our pathways to impact and capacity building, demonstrating how our innovation chain ensures delivery of results to end users. Capacity building is embedded in all phases of the project. PhD & PDRA exchange placements will facilitate skills transfer and establish an international team capable of addressing food security constraints in future projects. Our project enables BecA and ECABREN to expand research beyond their respective ILRI and CIAT core-funded activities and in line with priorities developed in consultation with African national partners.
Committee Not funded via Committee
Research TopicsCrop Science, Plant Science
Research PriorityX – Research Priority information not available
Research Initiative Sustainable Crop Production Research for International Development (SCPRID) [2011]
Funding SchemeX – not Funded via a specific Funding Scheme
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