Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or ....Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or light. The most efficient Rubiscos are more complex, with two different types of subunits which, in plants, are encoded in different subcellular compartments (nucleus and plastid). This proposal addresses the challenges associated with complementary engineering both genomes to substitute foreign Rubiscos into higher-plant chloroplasts.Read moreRead less
Can efficient algal variants of the photosynthetic CO2-fixing enzyme, Rubisco, be folded and assembled in functional forms in higher-plant plastids? We have shown that it is possible to alter the photosynthetic phenotype of a plant predictably and profoundly by engineering the plastid genome to replace the plant's CO2-fixing enzyme, Rubisco, with a bacterial homolog. Thus it may be possible to replace the plant enzyme with more efficient algal Rubiscos that would allow plants to grow with less l ....Can efficient algal variants of the photosynthetic CO2-fixing enzyme, Rubisco, be folded and assembled in functional forms in higher-plant plastids? We have shown that it is possible to alter the photosynthetic phenotype of a plant predictably and profoundly by engineering the plastid genome to replace the plant's CO2-fixing enzyme, Rubisco, with a bacterial homolog. Thus it may be possible to replace the plant enzyme with more efficient algal Rubiscos that would allow plants to grow with less light, less water or less fertiliser. Before such desirable changes to the plant phenotype can be realised, some complex issues of modification, folding and assembly of Rubisco subunits need to be resolved. This proposal addresses them.Read moreRead less
Organophosphate pesticide degradation: evolved enzymes and biomimetics for bioremediation and medicine. Organophosphate (OP) pesticides are an indispensable part of modern agriculture - their use results in dramatically increased crop yields. However, they are toxic and can damage the environment and cause significant health problems. Enzymes are currently being used to treat runoff water that is contaminated with OPs. The same enzymes also have the potential to aid in the treatment of OP poison ....Organophosphate pesticide degradation: evolved enzymes and biomimetics for bioremediation and medicine. Organophosphate (OP) pesticides are an indispensable part of modern agriculture - their use results in dramatically increased crop yields. However, they are toxic and can damage the environment and cause significant health problems. Enzymes are currently being used to treat runoff water that is contaminated with OPs. The same enzymes also have the potential to aid in the treatment of OP poisoning. However, OP degrading enzymes could be improved in many ways - we will evolve these enzymes to enhance their catalytic properties - to enable them to act more efficiently on an increased number of OPs. Read moreRead less
Identifying potential barriers to transplanting modified forms of the CO2-fixing enzyme, Rubisco, into plants. Improving the ability of crops to use water, light and fertiliser more efficiently would have economic benefits and ease the environmental impacts associated with agricultural practices. It is thought that such improvements can be made by enhancing the efficiency of the photosynthetic protein, Rubisco, which fixes most of the CO2 in the biosphere. The research proposed here uses unique ....Identifying potential barriers to transplanting modified forms of the CO2-fixing enzyme, Rubisco, into plants. Improving the ability of crops to use water, light and fertiliser more efficiently would have economic benefits and ease the environmental impacts associated with agricultural practices. It is thought that such improvements can be made by enhancing the efficiency of the photosynthetic protein, Rubisco, which fixes most of the CO2 in the biosphere. The research proposed here uses unique Rubisco transplantation capabilities that I have developed to improve our fundamental understanding of how Rubisco is processed and its activity regulated in plants. This will pave the way for our ongoing efforts to engineer and transplant more efficient Rubisco into crops.Read moreRead less
Boosting C4 photosynthesis to climate proof crop yields. Building next generation C4 crops, such as maize, sugarcane and sorghum, to cope with drought and heat stress is requisite to ensure the supply of food and fodder. Here we will increase the content and / or catalytic efficiency of the primary carboxylase of C4 photosynthesis (PEPC) that supplies CO2 to the carbon concentrating mechanism and ensures high photosynthetic rates. We will develop new SynBio tools to create and test novel PEPC is ....Boosting C4 photosynthesis to climate proof crop yields. Building next generation C4 crops, such as maize, sugarcane and sorghum, to cope with drought and heat stress is requisite to ensure the supply of food and fodder. Here we will increase the content and / or catalytic efficiency of the primary carboxylase of C4 photosynthesis (PEPC) that supplies CO2 to the carbon concentrating mechanism and ensures high photosynthetic rates. We will develop new SynBio tools to create and test novel PEPC isoforms with desirable properties. Ultimately, the project aims to identify isoforms that improve plant fitness under stress conditions. Optimising PEPC activity will provide next generation solutions to improve water balance and carbon assimilation to keep C4 crops productive under future climates.Read moreRead less
Exploring the catalytic role of the Rubisco small subunit: a new target for improving carbon dioxide-fixation in plants. This project uses new biotechnological tools to improve the performance of the photosynthetic protein Rubisco, the primary carbon dioxide-fixing enzyme in plants. By supercharging photosynthesis, this research will help to boost yield and reduce water and nitrogen use in crops.
Rubisco for all climates: unlocking the enzyme's structure-function relations for more efficient photosynthesis. This projects biotechnological research will identify structural features in the carbon dioxide (CO2)-capturing enzyme from plants that improve its performance, particularly at warmer temperatures. This knowledge is vital for predicting the influence of climate change on crop productivity and paving the way for supercharging photosynthesis to boost crop performance.
Combining new synthetic biology tools to boost crop CO2 capture and growth. A solution for improving crop yield is to enhance the carbon dioxide fixation properties of the enzyme Rubisco whose inefficient activity often limits plant growth. This project makes use of new synthetic biology capabilities to artificially evolve Rubisco in the laboratory and select for new versions with improved performance. These beneficial changes will be introduced into crop Rubisco using targeted gene editing appr ....Combining new synthetic biology tools to boost crop CO2 capture and growth. A solution for improving crop yield is to enhance the carbon dioxide fixation properties of the enzyme Rubisco whose inefficient activity often limits plant growth. This project makes use of new synthetic biology capabilities to artificially evolve Rubisco in the laboratory and select for new versions with improved performance. These beneficial changes will be introduced into crop Rubisco using targeted gene editing approaches and the improvements in photosynthesis, growth and yield evaluated. This information will aid complimentary biotechnological efforts seeking to supercharge photosynthesis and help deliver the second Green Revolution needed to meet the improvement required in future agriculture productivity and resource use.Read moreRead less
Directed evolution of enzymes for bioremediation: structure function studies of bimetalloenzymes. We will evolve enzymes that degrade organophosphate pesticides (OPs) that are used in Australian agriculture. Although these OPs were designed to kill insects they are closely related to chemical warfare agents and are known to be toxic to humans. Bacteria have acquired a number of enzymes that degrade some OPs. One such enzyme has been used in field trials demonstrating its potential to degrade OP ....Directed evolution of enzymes for bioremediation: structure function studies of bimetalloenzymes. We will evolve enzymes that degrade organophosphate pesticides (OPs) that are used in Australian agriculture. Although these OPs were designed to kill insects they are closely related to chemical warfare agents and are known to be toxic to humans. Bacteria have acquired a number of enzymes that degrade some OPs. One such enzyme has been used in field trials demonstrating its potential to degrade OP residues. However, many pesticides are not removed rapidly and OP-degrading enzymes require modification(s) if they are to be useful environmental reagents - this can be achieved with directed evolution. Read moreRead less
Engineered plant receptors as orthogonal neuronal switches. This project aims to develop synthetic biology methods to study brain function by utilising engineered plant receptors. This project will expand our ability to manipulate nerve cell function with high specificity and without side effects in freely behaving animals. Plant receptors will be developed into molecular tools in an iterative process that improves key properties using rational protein design. Expected outcomes include innovativ ....Engineered plant receptors as orthogonal neuronal switches. This project aims to develop synthetic biology methods to study brain function by utilising engineered plant receptors. This project will expand our ability to manipulate nerve cell function with high specificity and without side effects in freely behaving animals. Plant receptors will be developed into molecular tools in an iterative process that improves key properties using rational protein design. Expected outcomes include innovative and broadly-applicable neuroscience methods and an understanding of receptors involved in plant growth and defense. Benefits of this project include an enhanced capacity to generate knowledge, multidisciplinary training opportunities and patentable synthetic biology technologies.Read moreRead less