Stress responses in algae and plants

Algae and plants are frequently exposed to abiotic stresses such salt stress, toxic metal stress or nutrient deficiency stress. These organisms have sophisticated mechanisms to respond and adapt to these stresses. Unicellular green algae such as Chlamydomonas reinhardtii are ideal model systems to study stress responses in a photosynthetic organism at the single cell level. We are also using plants such as Arabidopsis thaliana as good models to study responses to stress, in particular Ca2+ signal responses.

1. Stress-mediated calcium homeostasis
A long standing research interest is involved in identifying the role of Ca2+ efflux transporters (Ca2+/H+ exchangers and Ca2+-ATPases) in regulating calcium nutrition and in generating Ca2+ signals in response to environmental stresses such as salt stress, drought or cold in Arabidopsis and in Chlamydomonas. Furthermore we are elucidating the mechanisms by which these transporters are regulated.

2. Cadmium tolerance in Chlamydomonas
Work in our lab has recently begun to look at some of the responses to cadmium and mechanisms for cadmium transport and tolerance in Chlamydomonas. This may have applications for the use of algae in metal-contaminated waste water bioremediation.

3. Responses to nutrient deficiency
We are examining some of the molecular and metabolic responses to nutrient deficiency including changes to the cell's elemental composition and the impact on carbohydrate and lipid metabolism.

Biofuel generation from microalgae

Microalgae are a diverse group of photosynthetic freshwater or marine organisms which have potential applications in sustainable biotechnology such as for providing renewable energy resources. We are investigating the potential of microalgae as a sustainable resource for producing biofuel.

1. Lipid productivity in algae
We are performing research to understand and enhance lipid accumulation in freshwater and marine algae utilising molecular biology, gene expression, metabolic and physiological analysis.

2. Potential of algae cultivation on wastewater
Algae have a potential dual use application on wastewater for the efficient removal of excess nitrogenous and phosphate pollutants and as a cultivation medium for biomass or biofuel generation. We are examining the characteristics of microalgae on wastewater.

Cation transport and homeostasis in plants

Plants have an essential requirement for many metals for normal growth and development, however, these metals can be toxic when present in excess. Non-essential, toxic metals such as cadmium can also be accumulated by plants. Plants must therefore carefully regulate their metal content. A wide variety of metal transporters are responsible for regulating the accumulation and partitioning of these metals throughout the cell.

1. Manganese transport and homeostasis
We are interested in the role of metal transporters in transition metal homeostasis and metal tolerance, focusing particularly on manganese. Such work can increase our understanding of how plants tolerate and respond to metal stress, which can be a major limiting factor to agricultural productivity.

Research in my lab is focussed towards understanding how plants and algae respond to environmental stresses and how they utilise metals, both essential metal nutrients and toxic metals. This is important for developing strategies to ultimately improve food production in crop plants. We are also using this understanding to develop algae that can accumulate and tolerate toxic compounds such as heavy metals for removing toxic metals from contaminated water. A second aspect of our research is in understanding how algae can efficiently produce oils that can be used as a biofuel. This will allow us to develop the use of algae as potential alternative renewable and sustainable fuel source.

Self funded PhD opportunities in the Pittman lab:

Utilisation of microalgae for sustainable biotechnology

Microalgae are a diverse group of photosynthetic freshwater or marine organisms that are widely studied with regard to their ecology or as model organisms in biological research. It is apparent that there is increasing potential in using microalgae for a variety of processes, particularly when coupled with powerful molecular techniques that allow their genetic engineering and manipulation. There is particular interest in the use of microbes in sustainable biotechnology - the development of novel ‘green’ processes for solving some of the world’s urgent needs such as for renewable energy resources and for environmental clean-up. Recent projects in the lab are investigating the use of microalgae for bioremediation purposes, such as through the accumulation of toxic metals like cadmium, or the potential of microalgae as a sustainable resource for producing biofuel. This project will further investigate and develop these organisms for sustainable bioenergy or bioremediation strategies. The project will provide training in a variety of experimental techniques including molecular biology, biochemical and cell biology skills.

Further references:

Bajhaiya A.K., Ziehe Moreira J., Pittman J.K. (2017) Transcriptional engineering of microalgae: prospects for high-value chemicals. Trends in Biotechnology 35:95-99

Driver T., Bajhaiya A., Pittman J.K. (2014) Potential of bioenergy production from microalgae. Current Sustainable/Renewable Energy Reports 1:94-103

Pittman J.K., Dean A.P., Osundeko O. (2011) The potential of sustainable algal biofuel production usingwastewater resources. Bioresource Technology 102:17-25 

There is no funding directly associated with this project but we will consider applicants who can gain funding such as from a government scholarship, Commonwealth Scholarships, etc. 

For informal enquiries, contact Dr Jon Pittman ([email protected])