Cadmium (Cd) is a highly toxic element to human beings and other forms of life. It is classified as a probable human carcinogen. Cd exists naturally in soil at low concentrations but could reach high level in certain areas. Nitrogen (N) is the mineral element that plants require in the greatest quantity. Cd accumulation in plants is shown to be related to N status. NO3- and NH4- are two major N supply forms which contribute significantly to rhizosphere pH, an important factor regulating Cd availability in the environment. Cd toxicity, root morphology and architecture might be affected by the application of different concentrations of nitrate and ammonium. Management of N sources could be a promising agronomic strategy to reduce Cd contamination in crops. My project is composed of two parts. Firstly, I will study the relationship between NO3-, NH4- supply and Cd mobility in plants (Arabidopsis thaliana). Secondly, I will also develop a soil sensor to measure the free Cd concentration in rhizosphere under different N forms applied.

Hongxin.Sun@jic.ac.uk

Magnesium Homeostasis in Plants

Magnesium is an essential ion for all cells of all known organisms, since it is the counter-ion chelating the ATP molecule, the energy currency of cells. The ion also plays a role in stabilisation of structures of ribosomes and DNA oligomers, and in photosynthesis as the central ion of Chlorophyll.
Although it is vital, not much is known about the way in which plants sense the levels of Magnesium present in the environment and regulate uptake and distribution of the ion, even though the levels are clearly regulated very tightly.

There is an urgent problem with Magnesium-nutrition in plants; studies have shown that the Mg²⁺-content of many of the major cereals has declined since the “Green Revolution”, and yields may be suffering because of it. In addition, it is estimated that about two thirds of the world’s population are not receiving the recommended daily intake of this ion, with possible health consequences.

This project therefore aims to identify components of the Magnesium regulatory network via a mutant screen and Genome-Wide Association Studies (GWAS), and to characterise components found functionally. We then plan to use Bioinformatics and mathematical modelling to elucidate the Mg network in plants and address the issues outlined.

Contact: Siegfried.Leher@jic.ac.uk

Engineering plant-microbe interactions for enhanced nitrogen assimilation

After water, available nitrogen (N) is the most limiting nutrient for plant growth. Present day agriculture is heavily dependent on ammonia fertilizer as N source. Industrial scale synthesis of ammonia (N fertilizer) by Haber Bosch process uses ~150 bar pressure and ~400 °C temperature. Interestingly nitrogen fixing bacteria (diazotrophs) can do this reaction in atmospheric pressure and normal temperatures with the help of a catalyst (metallo-enzyme) called nitrogenase. This biological nitrogen fixation can be a promising alternative to the present day chemical fertilizers.

Regulation of nitrogen fixation related genes in response to specific physiological conditions makes it difficult to utilize bacterial nitrogen fixation.  Moreover,  N fertilizers added to the soil is not completely absorbed by plants leaving a significant portion in environment. This clearly demonstrates limitation of plant ammonium transporters and highlights the necessity to improve plant nitrogen use efficiency (NUE) by substituting its native ammonium transporters with efficient ammonium transporters.

My work is primarily to engineer new symbiotic relation between plants and diazotrophic bacteria, simultaneously improving NUE in plants by engineering efficient ammonium transporters.

This project is in collaboration with Prof Ray Dixon in Molecular Microbiology.

Contact: Sankarakrishna.Pilla@jic.ac.uk

Cover crops and below ground biodiversity – measuring the potential of different farming systems to improve soil fertility

Cover crops are among the oldest agricultural techniques still in use. Their adoption has been proven to have mostly beneficial effects on yields, above-ground biodiversity and erosion control. However, little is known on the effects of cover crops on below-ground biodiversity and nutrient cycling. The project investigates nutrient flows and availability in a trophic-web perspective with samples taken from NIAB TAG New Farming Systems trial site.
My work is supervised by Professor Tony Miller and supported by the BBSRC through a NRP DTP iCASE studentship with Syngenta as the partners.

Contact: Marco.Fioratti@jic.ac.uk

Zinc is an essential micronutrient in all biological systems, being utilised by roughly 10% of the eukaryotic proteome. When plants can’t get enough zinc from the soil this can have severe biochemical and physiological consequences, resulting in massive crop yield losses and impacting zinc uptake in the human diet. However, zinc toxicity can be just as harmful as zinc deficiency and as such, plants have evolved a tightly coordinated zinc homeostasis network to maintain levels within a narrow concentration range. While many components of this homeostasis network have been found, there are still a lot of unanswered questions surrounding how plants sense changing zinc levels and regulate an appropriate response.

My project is looking for novel components of the zinc homeostasis network in the model plant species Arabidopsis thaliana through a genetic screen I am also interested in exploring zinc dynamics in response to various stimuli by utilising genetically encoded zinc FRET sensors.

My work is supervised by Professor Dale Sanders and Dr Tony Miller and is funded by the BBSRC as a DTP studentship.

Contact: Camilla.Stanton@jic.ac.uk

Acquisition of soil nutrients is important for plant survival. However excessive accumulation of nutrients results in toxicity. Plants use complex cellular and developmental strategies to adapt to their changing environment. Uptake and distribution of different nutrients are generally correlated and interact with each other. However the mechanism is not fully understood.

Currently I am working on a collaborative project between the groups of Dr Tony Miller and Dr Jeremy Murray with regard to characterization of three nitrate transporters from Medicago truncatula with regard to transport of nitrate as well as other potential substrates such as auxin. In addition, I have identified several novel transporters involved in long distance transport of zinc through phloem. Ionomic study in loss-of-function plants by ICP-MS and Sychrotron µ-XRF mapping are planned to further verify the biological function of these candidate genes in the future.

Contact: yi.chen@jic.ac.uk

The future of nitrogen (N) use as fertiliser is of growing concern for crop growers worldwide. N production through the Haber-Bosch process consumes 1% of global annual energy supply which has not only sustainability issues but also economical. Environmental concerns over its use by farmers has been hotly debated due to the potential adverse effects through it leaching into local wild and aquatic ecosystems, again with inferred economic disadvantages due to loss of product. Moreover there is growing pressure to instate legislation and regulations on farmer due to these detrimental effects, and such negative associations are recognised by the public. Because of these confounding factors it is important to study nitrogen use efficiency (NUE) in crops in order to potentially decrease N fertiliser use.

My research looks at practical ways of improving Nitrogen Use Efficiency in the UK forage crop industry through assessing gene expression patterns during growth in relation to harvested yields. I am also monitoring soil profile nitrate changes with patented sensors, and additionally investigating increased vegetative growth after biostimulant application for forage crops.

My work is supervised by Dr Tony Miller and is supported by BBSRC and the British Association of Green Crop Driers as an iCASE studentship.

Nicola.Capstaff@jic.ac.uk

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