Doctor Brendan Choat

Dr Brendan ChoatBrendan Choat obtained his BSc (Hons) in 1997 (JCU) and his PhD in 2003 (JCU).

From 2003-2005 he worked as a Post Doctoral Fellow at Harvard University in the Department of Organismic and Evolutionary Biology. He held a second Post Doctoral Fellowship in the Department of Viticulture and Enology at the University of California, Davis from 2005-2008.

In 2008 he returned to Australia to take up a Research Fellowship at ANU before moving to a Senior Research Lectureship at the Hawkesbury Institute for the Environment (UWS). He is an editor for the PrometheusWiki Project and on the editorial review board of Tree Physiology.

In 2010 he was awarded a Humboldt Fellowship for Experienced Researchers.

In 2013, Dr Choat was awarded an ARC Future Fellowship for his work in mapping drought responses in trees. 

Areas of Research / Teaching Expertise

The growth and survival of plants is strongly tied to the effective balance of water loss and carbon gain. In vascular plants, the xylem tissue constitutes a hydraulic system that must supply water to the transpiring leaf surface at a rate that allows for a net positive carbon balance.

The efficiency of this system is therefore of paramount importance to plant productivity and survival. However, water transported in the xylem is under tension and is therefore subject to cavitation. The resultant gas void (embolism) blocks conduits and leads to a reduction in hydraulic conductivity, which in turn can impact on leaf gas exchange and ultimately cause die back and death of the plant.

I am studying how the structure of the xylem achieves a compromise between features that promote efficiency of transport to the leaves while preserving safety from cavitation. The questions are of great importance in both natural and agricultural systems.

 

Awards and Recognition

Collaborative Research Scholarship, Research School of Biological Sciences, Australian National University, Canberra (1999)

  • Australian Society of Plant Physiologists Student Poster Prize, Combio Conference (1999)
  • Australian Postgraduate Award Scholarship, James Cook University (1998)
  • P.F. Brownell Medal for Plant Physiology (1998), JCU.
 

Grants / Current Projects

Xylem and phloem transport limitations and their role in drought-induced mortality of trees
Co-Researchers: David Tissue
Partner/Funding Body: University of Western Sydney
Period: 2011-2014

Drought and recovery: embolism spread and repair in conifer and angiosperm species
Partner/Funding Body: Australian Synchrotron Company Ltd
Period: 2013

Observation of embolism formation and refilling in plants using synchrotron based x-ray micro computed tomography
Partner/Funding Body: Australian Synchrotron Company Ltd
Period: 2012

Climate change effects on decomposition of coarse woody debris, as mediated by wood traits and fungal communities
Co-researchers: Jeff Powell and Peter Reich
Partner/Funding Body: University of Western Sydney
Period: 2011-2013

Fundamental aspects of water transport in plants
Co-Researchers: Hosted by Dr Steven Jansen at Ulm University
Partner/Funding Body: Humboldt Fellowship for Experienced Researchers
Period: 2010-2012

Travel funding to conduct experiments at the Advanced Light Source in Berkeley California
Partner/Funding Body: Australian Synchrotron International Synchrotron Access Program.
Period: 2010

Visualizing xylem functional repair and elucidating its mechanisms in a variety of woody and herbaceous species
Co-Researchers: McElrone AJ, Brodersen C, Shackel KA, Matthews MA
Partner/Funding Body: Advanced Light Source, General Sciences Proposals
Period: 2010

Salinity tolerance along an aridity gradient: linking physiological processes with morphological constraints on leaf function in mangroves
Co-Researchers: Ball MC, Lovelock CE, Sack L
Partner/Funding Body: ARC Discovery Grant
Period: 2010-2012

The role of systems level properties in the transport function of the xylem network
Co-Researchers: Matthews MA, McElrone AJ, Phillips R, Shackel KA 
Partner/Funding Body: NSF, Integrative Organismal Systems Program UC Davis
Period: 2008-2011

Australian Vegetation Function Network Working Group 63: Xylem Functional Traits
Co-Researchers: Jansen S
Period: 2009

Functional studies of pit membrane thickenings in angiosperms
Co-Researchers: Jansen S
Partner/Funding Body: Lennox Boyd Memorial Trust Fund
Period: 2005

The effects of seasonal drought on hydraulic architecture and vulnerability to embolism in Cordia
Partner/Funding Body: Mellon Exploration Grant, Smithsonian Tropical Research Institute and Organisation of Tropical Studies
Period: 2003

Selected Publications

Brodersen C, Jansen S, Choat B, Rico C, Pittermann J, (2014) 'Cavitation resistance in seedless vascular plants: The structure and function of interconduit pit membranes', Plant Physiology, vol.165, no.2, pp 895-904

Duan H, Duursma RA, Huang G, Smith RA, Choat B, O'Grady AP, Tissue DT, (2014) 'Elevated [CO2] does not ameliorate the negative effects of elevated temperature on drought-induced mortality in Eucalyptus radiata seedlings', Plant, Cell and Environment, vol.37, no.7, pp 1598-1613

Martorell S, Diaz-Espejo A, Medrano H, Ball MC, Choat B, (2014) 'Rapid hydraulic recovery in Eucalyptus pauciflora after drought: linkages between stem hydraulics and leaf gas exchange', Plant Cell and Environment, vol.37, no.3, pp 617-626

Brodersen CR, Choat B, Chatelet DS, Shackel KA, Matthews MA, McElrone AJ, (2013) 'Xylem vessel relays contribute to radial connectivity in grapevine stems (Vitis Vinifera and V. Arizonica; Vitaceae)', American Journal of Botany, vol.100, no.2, pp 314-321  

Brodersen CR, McElrone AJ, Choat B, Lee EF, Shackel KA, Matthews MA, (2013) 'In Vivo Visualizations of Drought-Induced Embolism Spread in Vitis vinifera', Plant Physiology, vol.161, no.4, pp 1820-1829 

Choat B (2013) 'Predicting thresholds of drought-induced mortality in woody plant species', Tree Physiology, vol.33, no.7, pp 669-671  

Choat B, Way D, (2013) 'Predicting thresholds of drought-induced mortality in woody plant species', Tree Physiology, vol.33, no.7, pp 669-671

Cochard H, Badel E, Herbette S, Delzon S, Choat B, Jansen S, (2013) 'Methods for measuring plant vulnerability to cavitation: a critical review', Journal of Experimental Botany, vol.64, no.15, pp 4779-4791

Duan H, Amthor JS, Duursma RA, O'Grady AP, Choat B, Tissue DT, (2013) 'Carbon dynamics of eucalypt seedlings exposed to progressive drought in elevated [CO2] and elevated temperature', Tree Physiology, vol.33, no.8, pp 779-792

McElrone AJ, Choat B, Parkinson DY, MacDowell AA, Brodersen CR, (2013) 'Using high resolution computed tomography to visualize the three dimensional structure and function of plant vasculature', Journal of Visualized Experiments, vol.74

Pfautsch S, Aspinwall M, Drake J, Choat B, Tissue D, Burykin T, Tjoelker M, (2013) 'Putting the puzzle together: Investigating hydraulic functioning and water transport at high spatial resolution in tall trees', Acta Horticulturae, vol.991, pp 245-252

Choat B, Jansen S, Brodribb TJ, Cochard H, Delzon S, Bhaskar R, Bucci SJ, Feild TS, Gleason SM, Hacke UG, Jacobsen AL, Lens F, Maherali H, Martinez-Vilalta J, Mayr S, Mencuccini M, Mitchell PJ, Nardini A, Pittermann J, Pratt RB, Sperry JS, Westoby M, Wright IJ, Zanne AE, (2012) 'Global convergence in the vulnerability of forests to drought', Nature, vol.491, no.7426, pp 752-755

McElrone AJ, Brodersen CR, Alsina MM, Drayton WM, Matthews MA, Shackel KA, Wada H, Zufferey V, Choat B, (2012) 'Centrifuge technique consistently overestimates vulnerability to water stress-induced cavitation in grapevines as confirmed with high-resolution computed tomography', New Phytologist, vol.196, no.3, pp 661-665

Melcher PJ, Holbrook NM, Burns MJ, Zwieniecki MA, Cobb AR, Brodribb TJ, Choat B, Sack L, (2012) 'Measurements of stem xylem hydraulic conductivity in the laboratory and field', Methods in Ecology and Evolution, vol.3, no.4, pp 685-694

Brodersen CR, Lee EF, Choat B, Jansen S, Phillips RJ, Shackel KA, McElrone AJ, Matthews MA, (2011) 'Automated analysis of three-dimensional xylem networks using high-resolution computed tomography', New Phytologist, vol.191, no.4, pp 1168-1179

Choat B, Medek DE, Stuart SA, Pasquet-Kok J, Egerton JJG, Salari H, Sack L, Ball MC, (2011) 'Xylem traits mediate a trade-off between resistance to freeze-thaw-induced embolism and photosynthetic capacity in overwintering evergreens', New Phytologist, vol.191, no.4, pp 996-1005

Lens F, Sperry JS, Christman MA, Choat B, Rabaey D, Jansen S, (2011) ‘Testing hypotheses that link wood anatomy to cavitation resistance and hydraulic conductivity in the genus Acer’, New Phytologist, vol.190, no.3, pp 709-723

Brodersen C, McElrone AJ, Choat B, Matthews MA, Shackel KA, (2010) 'The dynamics of embolism repair in xylem: in vivo visualizations using High Resolution Computed Tomography', Plant Physiology, vol.154, no.3, pp 1088–1095

*Choat B, Drayton WM, Brodersen C, Matthews MA, Shackel KA, Wada H, McElrone AJ, (2010) 'Measurement of vulnerability to water-stress induced cavitation in grapevine: a comparison of four techniques applied to a long-vesseled species', Plant Cell and Environment, vol.33, no.9, pp 1502-1512 (*first two authors share lead authorship)

Lens F, Sperry JS, Christman MA, Choat B,  Rabaey D, Jansen S, (2010) ‘Testing hypotheses that link wood anatomy to cavitation resistance and hydraulic conductivity in the genus Acer’, New Phytologist, DOI: 10.1111/j.1469-8137.2010.03518.x

*Pittermann J, Choat B, Jansen S, Stuart SA, Lynn L and Dawson T, (2010) 'The relationships between xylem safety and hydraulic efficiency in the Cupressaceae: the evolution of pit membrane form and function', Plant Physiology, vol.153, no.4, pp 1919–1931 (*first two authors share lead authorship)

Sack L, Cornwell WK, Santiago LS, Barbour MM, Choat B, Evans JR, Munns R, Nicotra, A, (2010) 'A unique web resource for physiology, ecology and the environmental sciences: PrometheusWiki', Functional Plant Biology, vol.37, no.8, pp 687-693

Choat B, Gambetta GA, Shackel KA, Matthews MA, (2009) ‘Vascular function in grape berries across development and its relevance to apparent hydraulic isolation’, Plant Physiology, vol.151, no.3, pp 1677–1687

Choat B, Gambetta GA, Wada H, Shackel KA, Matthews MA, (2009) 'The effects of Pierce's disease on leaf and petiole hydraulic conductance in Vitis vinifera cv. Chardonnay', Physiologia Plantarum, vol.136, no.4, pp 384–394

Choat B, Pittermann, J, (2009) 'New insights into bordered pit structure and cavitation resistance in angiosperms and conifers', New Phytologist, vol.182, no.3, pp 557–560

*Jansen S. Choat B, Pletsers A, (2009) 'Morphological variation of intervessel pit membranes and implications to xylem function in angiosperms', American Journal of Botany, vol.96, no.2, pp 409-419 (*first two authors share lead authorship)

Choat B, Cobb AR, Jansen S, (2008) ‘Tansley Review: Structure and function of bordered pits: new discoveries and impacts on whole plant hydraulic function’, New Phytologist, vol.177, no.3, pp 608-625

Choat B, Sack L, Holbrook NM, (2007) 'Diversity of hydraulic traits in nine Cordia species growing in tropical rainforests with contrasting precipitation', New Phytologist, vol.175, no.4, pp 686-698

Cobb AR, Choat B, Holbrook NM, (2007) 'Dynamics of freeze-thaw embolism in Smilax rotundifolia (Smilacaceae)', American Journal of Botany, vol.94, no.4, pp 640–649

Jansen S, Sano Y, Choat B, Rabaey D, Lens F, Dute RR, (2007) 'Pit membranes in tracheary elements of Rosaceae and related families: new records of tori and pseudo-tori',  American Journal of Botany, vol.94, no.4, pp 503–514

Stuart SA, Choat B, Martin K, Holbrook NM and Ball MC, (2007) 'The role of freezing in defining the latitudinal limits of mangrove forests', New Phytologist, vol.173, no.3, pp 576-583

Choat B, Ball MC, Luly JG, Donnelly C, Holtum JAM, (2006), 'Seasonal patterns of leaf gas exchange and water relations in dry rainforest trees of contrasting leaf phenology', Tree Physiology, vol.26, no.5, pp 657-664

Choat B, Brodie TW, Cobb AR, Zwieniecki MA, Holbrook NM, (2006), 'Direct measurements of intervessel pit membrane hydraulic resistance in two angiosperm tree species', American Journal of Botany, vol.93, no.7, pp 993-1000

Lovelock CE, Ball MC, Choat B, Holbrook NM, Feller IC, (2006) 'Linking physiological processes with patterns in mangrove forest structure: Phosphorus deficiency limits canopy development, hydraulic conductivity and photosynthetic carbon gain in dwarf Rhizophora mangle', Plant, Cell and Environment, vol.29, no.5, pp 793-802

Choat B, Ball MC, Luly JG, Holtum JAM, (2005) 'Hydraulic architecture of deciduous and evergreen dry rainforest tree species from north-eastern Australia', Trees: Structure and Function, vol.19, no.3, pp 305–311

Choat B, Lahr E, Melcher PJ, Zwieniecki MA, Holbrook NM, (2005) 'The spatial pattern of air seeding thresholds in mature sugar maple trees', Plant, Cell and Environment, vol.28, no.9, pp 1082–1089

Choat B, Jansen S, Zwieniecki MA, Smets E, Holbrook NM, (2004) ‘Changes in pit membrane porosity due to deflection and stretching: the role of vestured pits’, Journal of Experimental Botany, vol.55, no.402, pp 1569-1575

Jansen S, Choat B, Vinckier S, Lens F, Schols P, Smets E, (2004) 'Intervascular pit membranes with a torus in the wood of Ulmus (Ulmaceae) and related genera', New Phytologist, vol.163, no.1, pp 51-59

Choat B, Ball M, Luly J, Holtum J, (2003) ‘Pit membrane porosity and water stress-induced cavitation in four co-existing dry rainforest tree species’, Plant Physiology, vol.131, no.1, pp 41-48

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Eucalyptus Leaf