Rice, rocks and the parasitic weed Striga: Increasing sustainable cereal production and protection in sub-Saharan Africa

Lead supervisor: Professor Julie Scholes, Animal and Plant Sciences
Co-supervisor(s): Professor David Beerling, Animal and Plant SciencesProfessor Jurriaan Ton, Animal and Plant Sciences; Dr Mathias Lorieux, International Center for Tropical Agriculture

Deadline: Thursday 23 February 2017

Applications for this project have now closed.

Project description

The parasitic weed Striga devastates the yields of maize, sorghum and rain-fed rice in Africa. Striga species are difficult to control and innovative, sustainable solutions are urgently required. One possible strategy is to amend soils of degraded croplands with crushed silicate rocks to enhance the natural process of weathering. Plants enhance weathering of silicate rocks through acidification of the rhizosphere and by mycorrhization. Weathering of silicate rocks leads to the production of silicic acid, which can be taken up by some plants including rice. Uptake of silicic acid leads to increased resistance to some biotic stresses, due to mechanical strengthening of cell walls and/or to priming of biochemical and molecular defence pathways, both of which are key control points for molecular resistance against the parasitic weed Striga. This project aims to take a molecular genetic approach to accelerate the development of faster weathering rice varieties with enhanced resistance to Striga.

Following the Climate Change Conference (COP21), there is a commitment to seek innovative, sustainable solutions to increase crop yields whilst simultaneously sequestering atmospheric CO2. One strategy is to amend soils of degraded croplands with crushed silicate rocks to enhance the natural process of weathering and sequester anthropogenic carbon. Crop plants enhance weathering of silicate rocks through acidification of the rhizosphere and by mycorrhization. Benefits for food security arise through the production and uptake of silicic acid by some plants (including rice). This can lead to increased resistance to biotic stresses due to mechanical strengthening of cell walls and/or to priming of molecular defence pathways, both of which are key control points for resistance against the parasitic weed Striga. Striga causes devastating losses of cereal yields in sub Saharan Africa, worth over 7 billion US$ annually. This project aims to accelerate the development of faster weathering varieties of rain-fed rice with enhanced resistance to Striga. This will allow the development of a low cost, sustainable control strategy for resource poor farmers in Africa helping to improve food security whilst contributing to climate change mitigation. The student will determine how enhanced accumulation of silica increases resistance to Striga and exploit newly-available rice genetic resources to identify genes controlling the ability of roots to take up and silicic acid and exude protons and organic acids to accelerate weathering. The student will benefit from an exciting project that combines molecular genetic and biogeochemical expertise of the supervisors to deliver new breakthroughs in this field.

Keywords: striga, parasitic weeds, weathering, silica, climate change, rice

Subject areas: Agricultural Sciences, Biochemistry, Botany/Plant Science, Genetics, Molecular Biology, Pathology, Climate Change

Funding notes

This four-year studentship will be fully funded at Home/EU or international rates. Support for travel and consumables (RTSG) will also be made available at standard rate of £2,627 per annum, with an additional one-off allowance of £1,000 for a computer in the first year.  Students will receive an annual stipend of £17,336.