A5009709943- Plant Water Relations and Carbon Dynamics
- Plant responses to elevated CO2
- Plant responses to water stress
- Plant Stress Responses and Tolerance
- Atmospheric and Environmental Gas Dynamics
- Ecology and Vegetation Dynamics Studies
- Climate variability and models
- Plant Parasitism and Resistance
- Plant Molecular Biology Research
- Geological and Geochemical Analysis
- Photosynthetic Processes and Mechanisms
- Plant nutrient uptake and metabolism
- Plant Diversity and Evolution
- Geology and Paleoclimatology Research
- Seed Germination and Physiology
- Forest ecology and management
- Paleontology and Stratigraphy of Fossils
- Greenhouse Technology and Climate Control
- Tree-ring climate responses
- Plant Reproductive Biology
- Plant and animal studies
- Light effects on plants
- Hydrocarbon exploration and reservoir analysis
- Fern and Epiphyte Biology
- Biocrusts and Microbial Ecology
The University of Sydney
2014-2024
University of California, San Diego
1998-2018
Scripps Institution of Oceanography
2018
In-Q-Tel
2013
University of Sheffield
2009-2012
James Cook University
1999-2010
Harvard University
2003-2004
University of Toronto
2003
Australian Institute of Tropical Health and Medicine
2003
Australian National University
1995-1999
Stomatal pores are microscopic structures on the epidermis of leaves formed by 2 specialized guard cells that control exchange water vapor and CO(2) between plants atmosphere. size (S) density (D) determine maximum leaf diffusive (stomatal) conductance (g(c(max))) to sites assimilation. Although large variations in D observed fossil record have been correlated with atmospheric CO(2), crucial significance similarly S has overlooked. Here, we use physical diffusion theory explain why changes...
Maximum and minimum stomatal conductance, as well size rate of response, are known to vary widely across plant species, but the functional relationship between these static dynamic properties is unknown. The objective this study was test three hypotheses: (i) operating conductance under standard conditions (gop) correlates with prior morning light [gmin(dawn)]; (ii) (S) negatively correlated gop maximum opening in response light, (dg/dt)max; (iii) instantaneous water-use efficiency (WUE)...
Summary Improvement in crop water‐use efficiency ( WUE ) is a critical priority for regions facing increased drought or diminished groundwater resources. Despite new tools the manipulation of stomatal development, engineering plants with high remains challenge. We used Arabidopsis epidermal patterning factor EPF mutants exhibiting altered density to test whether could be improved directly by genes controlling density. Specifically, we tested constitutive overexpression 2 reduced and maximum...
To investigate the impact of manipulating stomatal density, a collection Arabidopsis epidermal patterning factor (EPF) mutants with an approximately 16-fold range densities (approx. 20-325% that control plants) were grown at three atmospheric carbon dioxide (CO(2)) concentrations (200, 450 and 1000 ppm), 30 per cent or 70 soil water content. A strong negative correlation between size (S) density (D) was observed, suggesting factors D also affect S. Under some but not all conditions, mutant...
ABSTRACT Maximum stomatal conductance to water vapour and CO 2 ( g wmax , cmax respectively), which are set at the time of leaf maturity, determined predominantly by size S ) density D ). In theory, many combinations yield same so there is no inherent correlation between or maximum conductance. However, using basic equations for gas diffusion through stomata different sizes, we show that a negative offers several advantages, including plasticity in with minimal change epidermal area...
Abstract Earth's atmospheric CO 2 concentration ( c a ) for the Phanerozoic Eon is estimated from proxies and geochemical carbon cycle models. Most estimates come with large, sometimes unbounded uncertainty. Here, we calculate tightly constrained of using universal equation leaf gas exchange, key variables obtained directly isotope composition stomatal anatomy fossil leaves. Our new estimates, validated against ice cores direct measurements , are less than 1000 ppm most Phanerozoic, Devonian...
Abscisic acid (ABA)-driven stomatal regulation reportedly evolved after the divergence of ferns, during early evolution seed plants approximately 360 million years ago. This hypothesis is based on observation that stomata certain fern species are unresponsive to ABA, but exhibit passive hydraulic control. However, ABA-induced closure was detected in some mosses and lycophytes. Here, we observed a number ABA signaling membrane transporter protein families diversified over evolutionary history...
Chloroplast retrograde signaling networks are vital for chloroplast biogenesis, operation, and signaling, including excess light drought stress signaling. To date, has been considered in the context of land plant adaptation, but not regarding origin evolution cascades linking function to stomatal regulation. We show that key elements process, nucleotide phosphatase (SAL1) 3'-phosphoadenosine-5'-phosphate (PAP) metabolism, evolved streptophyte algae-the algal ancestors plants. discover an...
The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO 2 ) over long short timescales, as well potential drivers of evolutionary transitions. However, reconstructing CO beyond direct measurements requires use paleoproxies herein lies challenge, proxies differ in their assumptions, degree understanding, even reconstructed values. In this study, we critically evaluated, categorized, integrated available to create a high-fidelity transparently...
ABSTRACT Isohydric and anisohydric regulations of plant water status have been observed over several decades field, glasshouse laboratory studies, yet the functional significance mechanism both remain obscure. We studied seasonal trends in hydraulic properties a natural stand Eucalyptus gomphocephala through cycles varying environmental moisture (rainfall, groundwater depth, evaporative demand) order to test for isohydry provide physiological information mechanistic interpretation status....
ABSTRACT Gas exchange experiments were performed with 13 plant species that differ from each other in growth‐form and natural habitat. These comprised three herbaceous species, two ferns, temperate deciduous trees, five rainforest trees one liana wet tropical forest. The aims to investigate whether plants of similar habitats tended respond similarly a change leaf‐to‐air vapour pressure difference (VPD), compare their ratio intercellular ambient partial pressures CO 2 for given conditions....
Summary The evolution of C 4 photosynthesis in plants has allowed the maintenance high CO 2 assimilation rates despite lower stomatal conductances. This underpins greater water‐use efficiency species and their tendency to occupy drier, more seasonal environments than 3 relatives. basis interspecific variation maximum conductance water ( g max ), as defined by density size, was investigated a common‐environment screening experiment. Stomatal traits were measured 28 from seven grass lineages,...
Simulating global fluxes of water, carbon, and energy at the land surface requires accurate versatile models stomatal conductance, currently represented by structurally similar interchangeable forms that share weaknesses environmental extremes. ### Glossary ABA : abscisic acid BB : Ball-Berry MED : Medlyn RuBP : ribulose 1,5-bisphosphate CLM : community model WUE : water-use efficiency optimization * ### Glossary ABA : acid BB Ball-Berry MED Medlyn RuBP 1,5-bisphosphate CLM ...
In response to short-term fluctuations in atmospheric CO(2) concentration, c(a), plants adjust leaf diffusive conductance CO(2), g(c), via feedback regulation of stomatal aperture as part a mechanism for optimizing uptake with respect water loss. The operational range this elaborate control is determined by the maximum g(c(max)), which set size (S) and density (number per unit area, D) stomata on surface. Here, we show that, long-term exposure elevated or subambient alter g(c(max)) direction...
Abstract Earth system models ( ESM s) rely on the calculation of canopy conductance in land surface LSM to quantify partitioning energy, water, and CO 2 fluxes. This is achieved by scaling stomatal conductance, g w , determined from physiological developed for leaves. Traditionally, have been semi‐empirical, combining functions with empirically calibration constants. More recently, optimization theory has applied model s under premise that it a stronger grounding might ultimately lead...
ABSTRACT A decrease in steady‐state leaf transpiration rate with increased vapour pressure difference between and air, which is reversible independent of water status, evidence for feedforward control stomatal aperture (Cowan 1977). recent survey gas exchange data by Monteith (1995), covering 52 sets measurements on 16 species, reported that was rare usually reliant a single point. We conducted experiments an additional 13 species observed apparent response only two. However, the not...
The relationship between stomatal aperture (a) and guard cell pressure (Pg) was measured directly in four different species (Vicia faba, Tradescantia virginiana, Ginkgo biloba Nephrolepis exaltata) using a special probe technique. effect of epidermal turgor (Pep) on this also T. virginiana. sigmoidal for V. faba but entirely convex G. N. exaltata. Epidermal found to have pronounced closing stomata Maximum with full (0·92 MPa) about half that zero turgor. Also, virginiana did not begin open...
ABSTRACT The capacity of plants to fix carbon is ultimately constrained by two core plant attributes: photosynthetic biochemistry and the conductance CO 2 diffusion from atmosphere sites carboxylation in chloroplasts, predominantly stomatal conductance. Analysis fossilized remains shows that density (number per unit area, D ) size (length width, S have fluctuated widely over Phanerozoic Eon, indicating changes maximum Parallel are likely taken place leaf biochemistry, which maximal rubisco...
Summary The considerable drought tolerance of wild cereal crop progenitors has diminished during domestication in the pursuit higher productivity. Regaining this trait crops is essential for global food security but requires novel genetic insight. Here, we assessed molecular evidence natural variation barley ( Hordeum spontaneum ), emmer wheat Triticum dicoccoides and Brachypodium species collected from dry moist habitats at Evolution Canyon, Israel (ECI). We report that prevailing vs...