Disorder as a novel determinant of photosynthetic structure and function: an experimental study. Australia enjoys a world reputation in photosynthesis research, typified by hosting the 2001 International Photosynthesis Congress. It also has a claim to fame for theoretical work in non-equilibrium thermodynamics concerning production of disorder or entropy, yielding new insights into planetary climates. This experimental project investigates the novel relation between entropy/entropy production ....Disorder as a novel determinant of photosynthetic structure and function: an experimental study. Australia enjoys a world reputation in photosynthesis research, typified by hosting the 2001 International Photosynthesis Congress. It also has a claim to fame for theoretical work in non-equilibrium thermodynamics concerning production of disorder or entropy, yielding new insights into planetary climates. This experimental project investigates the novel relation between entropy/entropy production and the structure/function of the solar powerhouse of plants (chloroplasts), and addresses fundamental questions at the interface of biology and physics. The research explores chloroplasts as a manifestation of the all-pervading Second Law of Thermodynamics, advancing Australia's contribution to basic science and helping to train researchers.Read moreRead less
Using the fractionation of hydrogen and carbon isotopes to analyse the mechanisms of the primary processes of photosynthesis. The primary processes of CO2 fixation and reduction in photosynthesis leave their signatures in the isotopic composition of organic matter. Although these signatures are used widely in geochemistry, biology and climatology to infer the dynamics and history of the biosphere, the information they provide about the mechanisms of the processes that produce them has not been e ....Using the fractionation of hydrogen and carbon isotopes to analyse the mechanisms of the primary processes of photosynthesis. The primary processes of CO2 fixation and reduction in photosynthesis leave their signatures in the isotopic composition of organic matter. Although these signatures are used widely in geochemistry, biology and climatology to infer the dynamics and history of the biosphere, the information they provide about the mechanisms of the processes that produce them has not been exploited fully. We propose to map the underlying biochemistry responsible for fractionation of hydrogen isotopes, to assess its ability to indicate the water relations of plants, and to use carbon-isotope discrimination to probe the catalytic chemistry of the CO2-fixing enzyme, Rubisco.Read moreRead less
Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein a ....Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein assembles without difficulty. This project will devise strategies for controlling this variability that will facilitate attempts to exploit plastid transformation for transplanting better versions of the photosynthetic CO2-fixing enzyme, Rubisco, into plants to improve their growth efficiency in terms of water, fertiliser and light use.Read moreRead less
Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will cap ....Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will capitalize on our progress in describing the functional genetics of this process and aims to elucidate the mechanism of active CO2 uptake and the way that cells sense the ambient CO2 concentration. The information gained is likely to be useful for designing improved crops.Read moreRead less
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
Clocks in crops: exploring the role of circadian rhythms in crop adaptation. The project aims to analyse how the circadian clock provides adaptive advantages in legumes and cereals, two major crop groups of global importance. The project expects to produce new fundamental knowledge about how the clock in these crops coordinates their development, physiology, and metabolism in response to environmental cues. The anticipated outcome is a better understanding of key similarities and differences in ....Clocks in crops: exploring the role of circadian rhythms in crop adaptation. The project aims to analyse how the circadian clock provides adaptive advantages in legumes and cereals, two major crop groups of global importance. The project expects to produce new fundamental knowledge about how the clock in these crops coordinates their development, physiology, and metabolism in response to environmental cues. The anticipated outcome is a better understanding of key similarities and differences in clock functions in different species. Another is knowledge of how the ancient clock gene variants still in use today may limit the current or future performance of those crops. This will provide significant benefits, such as to improve productivity of crop plants in diverse and changing environments.Read moreRead less
New approaches to unravelling post-translational controls operating on the cyanobacterial carbon dioxide concentrating mechanism. Marine blue-green algae contribute to global primary productivity but their carbon dioxide acquisition processes are poorly understood. The project will employ mutagenesis and genome sequencing to discover the controls that regulate carbon dioxide uptake processes required for efficient photosynthesis and use this data to aid in engineering crop plants that use less w ....New approaches to unravelling post-translational controls operating on the cyanobacterial carbon dioxide concentrating mechanism. Marine blue-green algae contribute to global primary productivity but their carbon dioxide acquisition processes are poorly understood. The project will employ mutagenesis and genome sequencing to discover the controls that regulate carbon dioxide uptake processes required for efficient photosynthesis and use this data to aid in engineering crop plants that use less water.Read moreRead less
Adapting cyanobacterial bicarbonate transporters for application in crop improvement. Marine blue-green algae contribute to global primary productivity but their carbon dioxide (CO2) acquisition processes are poorly understood. The project will determine protein structure and regulatory controls present in two classes of bicarbonate transporters required for efficient photosynthesis, and use this data towards the engineering crop plants that use less water.
ARC Centre of Excellence for Plant Success in Nature and Agriculture. The ARC CoE for Plant Success in Nature and Agriculture will discover the adaptive strategies underpinning productivity and resilience in diverse plants and deepen knowledge of the genetic and physiological networks driving key traits. Using novel quantitative and computational approaches, the Centre will link gene networks with traits across biological levels, giving breeders an unparalleled predictive capacity. The Centre wi ....ARC Centre of Excellence for Plant Success in Nature and Agriculture. The ARC CoE for Plant Success in Nature and Agriculture will discover the adaptive strategies underpinning productivity and resilience in diverse plants and deepen knowledge of the genetic and physiological networks driving key traits. Using novel quantitative and computational approaches, the Centre will link gene networks with traits across biological levels, giving breeders an unparalleled predictive capacity. The Centre will accelerate technologies to transfer successful networks into crops and build legal frameworks to secure this knowledge. With a uniquely multidisciplinary team, the Centre will deliver new strategies to address the problems of food security and climate change, establishing Australia as a global leader in these areas.Read moreRead less
Enhancing plant photosynthesis by engineering the carbon dioxide (CO2)-fixing enzyme Rubisco. Improving the ability of crops to use water, sunlight and fertiliser more efficiently would have economic benefits for Australia and ease the environmental impacts associated with agricultural practices. Photosynthesis research has confirmed that such improvements are theoretically possible by enhancing the efficiency of the protein, Rubisco, which initiates the conversion of carbon dioxide into carbon ....Enhancing plant photosynthesis by engineering the carbon dioxide (CO2)-fixing enzyme Rubisco. Improving the ability of crops to use water, sunlight and fertiliser more efficiently would have economic benefits for Australia and ease the environmental impacts associated with agricultural practices. Photosynthesis research has confirmed that such improvements are theoretically possible by enhancing the efficiency of the protein, Rubisco, which initiates the conversion of carbon dioxide into carbon compounds required for growth. The biotechnological research proposed here uses unique capabilities to improve our understanding of structural features in Rubisco that influence its assembly and functional efficiency in plants. This knowledge will pave the way for transplanting more efficient Rubisco into crops to improve their growth.Read moreRead less