A5037345125- Photosynthetic Processes and Mechanisms
- Plant responses to elevated CO2
- Plant Water Relations and Carbon Dynamics
- Algal biology and biofuel production
- Plant Stress Responses and Tolerance
- Light effects on plants
- Plant nutrient uptake and metabolism
- Plant Molecular Biology Research
- Crop Yield and Soil Fertility
- Microbial Metabolic Engineering and Bioproduction
- Plant tissue culture and regeneration
- CRISPR and Genetic Engineering
- Mitochondrial Function and Pathology
- Research in Cotton Cultivation
- Marine and coastal ecosystems
- Wheat and Barley Genetics and Pathology
- Genetics and Plant Breeding
- ATP Synthase and ATPases Research
- Species Distribution and Climate Change
- Plant and animal studies
- CO2 Reduction Techniques and Catalysts
- Soil Carbon and Nitrogen Dynamics
- Genomics and Phylogenetic Studies
- Plant responses to water stress
- Plant Genetic and Mutation Studies
Western Sydney University
2013-2025
Australian National University
2011-2022
ARC Centre of Excellence for Transformative Meta-Optical Systems
2016-2022
Australian Research Council
2016-2021
Cornell University
2008-2013
Ithaca College
2010-2011
University of Kentucky
2009
Rutgers, The State University of New Jersey
2007
A long-term strategy to enhance global crop photosynthesis and yield involves the introduction of cyanobacterial CO2-concentrating mechanisms (CCMs) into plant chloroplasts. Cyanobacterial CCMs enable relatively rapid CO2 fixation by elevating intracellular inorganic carbon as bicarbonate, then concentrating it around enzyme Rubisco in specialized protein micro-compartments called carboxysomes. To date, chloroplastic expression carboxysomes has been elusive, requiring coordinated almost a...
While marine phytoplankton rival plants in their contribution to global primary productivity, our understanding of photosynthesis remains rudimentary. In particular, the kinetic diversity CO2-fixing enzyme, Rubisco, unknown. Here we quantify maximum rates carboxylation (kcatc), oxygenation (kcato), Michaelis constants (Km) for CO2 (KC) and O2 (KO), specificity over (SC/O) Form I Rubisco from 11 diatom species. Diatom shows greater variation KC (23–68 µM), SC/O (57–116mol mol−1), KO (413–2032...
Improving global yields of important agricultural crops is a complex challenge. Enhancing yield and resource use by engineering improvements to photosynthetic carbon assimilation one potential solution. During the last 40 million years C(4) photosynthesis has evolved multiple times, enabling plants evade catalytic inadequacies CO(2)-fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco). Compared with their C(3) ancestors, combine faster rubisco biochemical...
Semidwarfing genes have improved crop yield by reducing height, improving lodging resistance, and allowing plants to allocate more assimilates grain growth. In wheat (
Plants operating C3 and C4 photosynthetic pathways exhibit differences in leaf anatomy carbon fixation biochemistry. Fully understanding this underpinning biochemical variation is requisite to identifying solutions for improving efficiency growth. Here we refine assay methods accurately measuring the carboxylase decarboxylase activities plant soluble protein. We show that extract preparation conditions are required measure NADP-malic enzyme phosphoenolpyruvate (pH 8, Mg2+, 22 °C)...
Engineering improved Rubisco for the enhancement of photosynthesis is challenged by alternate locations chloroplast rbcL gene and nuclear RbcS genes. Here we develop an RNAi-RbcS tobacco (Nicotiana tabacum) master-line, tobRrΔS, producing homogenous plant rbcL-rbcS operon transformation. Four genotypes encoding alternative rbcS genes adjoining 5′-intergenic sequences revealed that production was highest (50% wild type) in lines incorporating a whose codon use 5′ untranslated-region matched...
Photosynthetic manipulation provides new opportunities for enhancing crop yield. However, understanding and quantifying the importance of individual multiple manipulations on seasonal biomass growth yield performance target crops across variable production environments is limited. Using a state-of-the-art cross-scale model in APSIM platform we predicted impact altering photosynthesis enzyme-limited (Ac ) electron transport-limited (Aj rates, dynamics canopy photosynthesis, growth, formation...
Abstract Many C4 plants are used as food and fodder crops often display improved resource use efficiency compared to C3 plants. However, the response of future extreme conditions such heatwaves is less understood. Here, Setaria viridis, an emerging model grass, was grown under long-term high temperature stress for two weeks (42°C, 28°C). This resulted in stunted growth, but surprisingly had little impact on leaf thickness, area-based photosynthetic rates bundle sheath leakiness. Dark...
Abstract Plastomic replacement of the tobacco (Nicotiana tabacum) Rubisco large subunit gene (rbcL) with that from sunflower (Helianthus annuus; rbcLS) produced tobaccoRst transformants a hybrid consisting and small subunits (LsSt). The plants required CO2 (0.5% v/v) supplementation to grow autotrophically seed despite substrate saturated carboxylation rate, K m, for CO2/O2 selectivity LsSt enzyme mirroring kinetically equivalent Rubiscos. Consequently, at onset exponential growth when...
Most physiology comparisons of C3 and C4 plants are made under current or elevated concentrations atmospheric CO2 which do not reflect the low environment photosynthesis has evolved. Accordingly, photosynthetic nitrogen (PNUE) water (PWUE) use efficiency, activity carboxylases [Rubisco phosphoenolpyruvate carboxylase (PEPC)] decarboxylases [NADP-malic enzyme (NADP-ME) carboxykinase (PEP-CK)] were compared in eight grasses with NAD-ME, PCK, NADP-ME subtypes, one grass, C3–C4 grass grown...
In maize, salinity reduced photosynthesis by decreasing stomatal conductance. Shade downregulated PEPC more than Rubisco, leading to decreased bundle-sheath CO2 leakiness. The treatments elicited plasticity in NADP-ME/PEP-CK activity ratio.
Photosynthesis has become a major trait of interest for cereal yield improvement as breeders appear to have reached the theoretical genetic limit harvest index, mass grain proportion crop biomass. Yield improvements afforded by adoption green revolution dwarfing genes wheat and rice are becoming exhausted, in biomass radiation use efficiency now sought these crops. Exploring diversity photosynthesis is possible using high-throughput techniques, low-cost genotyping facilitates discovery...
The haptophyte algae are a cosmopolitan group of primary producers that contribute significantly to the marine carbon cycle and play major role in paleo-climate studies. Despite their global importance, little is known about assimilation haptophytes, particular kinetics Form 1D CO2-fixing enzyme, Rubisco. Here we examine Rubisco properties three haptophytes with range pyrenoid morphologies (Pleurochrysis carterae, Tisochrysis lutea, Pavlova lutheri) diatom Phaeodactylum tricornutum exhibit...
The inability to assemble Rubisco from any photosynthetic eukaryote within Escherichia coli has hampered structure-function studies of higher plant Rubisco. Precise genetic manipulation the tobacco chloroplast genome (plastome) by homologous recombination facilitated successful production transplastomic lines that have either mutated large subunit (L) gene, rbcL, or replaced it with foreign variants. Here capacity a new line, (cm)trL, augment future engineering is demonstrated. Initially...
Ribonuclease J is an essential enzyme, and the Bacillus subtilis ortholog possesses both endoribonuclease 5′ → 3′ exoribonuclease activities. Chloroplasts also contain RNase J, which has been postulated to participate, as exo- endonuclease, in maturation of polycistronic mRNAs. Here we have examined recombinant Arabidopsis found endonucleolytic Virus-induced gene silencing was used reduce expression Nicotiana benthamiana , leading chlorosis but surprisingly few disruptions cleavage rRNA mRNA...
In C
Climate is an important factor limiting tree distributions and adaptation to different thermal environments may influence how populations respond climate warming. Given the current rate of warming, it has been hypothesized that in warmer, more thermally stable climates have limited capacity physiologically warming compared from cooler, seasonal climates. We determined a controlled environment several provenances widely distributed Eucalyptus tereticornis E. grandis adjusted their...
The high energy cost and apparently low plasticity of C4 photosynthesis compared with C3 may limit the productivity distribution plants in light (LL) environments. evolved numerous times, but it remains unclear how different biochemical subtypes perform under LL. We grew eight grasses belonging to three [NADP-malic enzyme (NADP-ME), NAD-malic (NAD-ME), phosphoenolpyruvate carboxykinase (PEP-CK)] shade (16% sunlight) or control (full conditions measured their photosynthetic characteristics at...
Summary C 4 plants achieve higher photosynthesis ( A n ) and intrinsic water use efficiency iWUE than 3 plants, but processes underpinning the variability in across three subtypes remain unclear, partly because we lack an integrated framework for quantifying contribution of diffusional biochemical limitations to photosynthesis. We exploited natural diversity among grasses develop original mathematical approach estimating eight key their relative . also developed a new formulation estimate...