Doctor Oula Ghannoum
- Awards and Recognition
- Grants / Current Projects
- Selected Publications
- Contact Details (opens in a new window)
Dr Ghannoum researches the biochemical underpinnings and physiological significance of evolutionary and ecological diversity within photosynthesis. She is internationally recognised for her pioneering research on C4 photosynthesis in grasses, for which she was awarded a highly-competitive ARC Postdoctoral Fellowship.
Currently, Dr Ghannoum is investigating the links between Rubisco catalysis, the CO2 concentrating mechanism and resource use efficiency in C4 plants. This research, conducted in collaboration with colleagues at ANU and CSIRO-PI, has significant translational potential for crop improvement and management of Australia’s fragile rangelands.



Together with researchers at the Institute, Dr Ghannoum is working on elucidating leaf-level processes which underlie the growth and water use responses of eucalypts to environmental change, in addition to their implications on understory dynamics and fire regimes in water- and nutrient-limited Australian woodlands.
Areas of Research / Teaching Expertise
Unit Coordinator for Plant Physiology (300609)
C4 photosynthesis
Global change biology
Awards and Recognition
1998: Christine Wieneke New Researcher Award, UWS, $3,000
2001-2003: Australian Postdoctoral Fellowship, ARC, $185,766
1998: Visiting Fellowship, Japanese Science and Technology, $8,000
1997: Rural Industries Research and Development Corporation, $2,200
Grants / Current Projects
External Funding:
- 2012 – 2014: ARC Discovery, $310,000
Rubisco for all climates: unlocking the enzyme's structure-function relations for more efficient photosynthesis.
Investigators: SM Whitney, O Ghannoum - 2010: Australian Institute of Nuclear Science & Engineering-AINSE Research Award, $6,108
Impacts of climate change on nitrogen uptake by eucalypt seedlings.
Investigators: O. Ghannoum, P. Milham - 2001 – 2003: ARC Postdoctoral Fellowship, $185,766
Causes and consequences of the differences in leaf biochemistry and structure between NAD-ME and NADP-ME C4 grasses (completed).
APD Fellow: O Ghannoum
Internal Funding:
- 2009: UWS Research Infrastructure Fund, $300,000
A Phytotron for Multitrophic Interactions on Plant Production Systems.
Investigators: M. Riegler, O. Ghannoum, and B. Bellotti - 2005: UWS International Research Initiative Scheme, $17,382
Using metabolomics to study the response of Australia’s tropical grasses to phosphorus deficiency (completed).
Investigators: O Ghannoum, JP Conroy and MJ Paul - 2005: UWS Internal Research Grant Scheme, $23,500
Using transcriptomics to compare the effects of phosphorus deficiency on the model plants arabidopsis and maize (completed).
Investigators: V Higgins and O Ghannoum - 2004: UWS Research Seed Grant Scheme, $7,500
Proteomics of the bundle sheath and mesophyll thylakoid membrane in maize (completed).
Investigator: O Ghannoum - 1998: UWS Internal Research Grant Scheme, $12,000
Relating carbon and nitrogen metabolism regulation to osmolyte accumulation in C4 grasses under water stress (completed).
Investigator: O Ghannoum - 1995 – 1996: ANU Collaborative Research Scholarship, $14,000
Response of C3 and C4 Panicum grasses to CO2 enrichment (completed).
PhD candidate: O Ghannoum
Student supervision and research projects
Research opportunities:

An ARC-funded PhD scholarship (top-up or stipend) is available for an eligible and motivated student to work with Dr Ghannoum on the diversity of CO2 concentrating mechanisms among C4 grasses. The project has gas exchange-stable isotope, biochemical and molecular components. Interested students are encouraged to contact Dr Ghannoum directly to discuss their suitability and the project details.
Other Honours and PhD research projects are available in areas related to the physiology, biochemistry and molecular biology of C3 and C4 photosynthesis. Interested students are encouraged to contact Dr Ghannoum personally to discuss project details. Examples of research projects include:
• An integrated approach to understanding variations in resource use efficiency among C4 plants
• Spatial and temporal variations in photosynthetic nitrogen economy in eucalypts
• Productivity and composition of understory vegetation under climate change
Research students:
- Anthony Newton (Hons candidate, started Feb 2012): Investigating the molecular plasticity of C4 photosynthesis. Supervisory panel: Sharwood and Ghannoum.
- Harshini Pinto (PhD candidate, started March 2011): Resource use efficiency of C4 grasses with different evolutionary origins. Supervisory panel: Ghannoum, Tissue and Conroy.
- Josephine Ontedhu (PhD candidate, started March 2010): Interaction of phosphorus nutrition with eucalypt responses to elevated [CO2] and temperature. Supervisory panel: Tissue, Ghannoum and Milham
- Gyro Sherwin (Hons candidate, completed May 2011): Impact of industrial-age climate change on nitrogen uptake and partitioning in Eucalyptus. Supervisory panel: Ghannoum, George, Kannangara, Tissue
- Harshini Pinto (Hons candidate, completed Dec 2010): Resource use efficiency of C4 grasses with different evolutionary origins. Supervisory panel: Tissue and Ghannoum
Selected Publications
Book Chapters
Ghannoum O, Evans JR, von Caemmerer S, (2009) Nitrogen and water use efficiency of C4 plants, in C4 Photosynthesis and Related CO2 Concentrating Mechanisms, Advances in Photosynthesis and Respiration series, (Eds) Raghavendra AS, Sage RF, Springer, Berlin
Ghannoum O, Searson M, Conroy J, (2006) Nutrient and water demands of plants under climate change, in Agroecosystems in a Changing Climate, Advances in Agroecology Series 12, (Eds) Newton PCD, Edwards G, Carran A, & Niklaus P, CRC Press, Boca Raton, FL, USA, pp 53–83
Journal Articles
Anderson IC, Drigo B, Keniry K, Ghannoum O, Chambers SM, Tissue DT, Cairney JW, (2013) 'Interactive effects of preindustrial, current and future atmospheric CO2 concentrations and temperature on soil fungi associated with two Eucalyptus species', FEMS Microbiology Ecology, vol.83, no.2, pp 425-437
Franks PJ, Adams MA, Amthor JS, Barbour MM, Berry JA, Ellsworth DS, Farquhar GD, Ghannoum O, Lloyd J, McDowell N, Norby RJ, Tissue DT, von Caemmerer S, (2013) 'Sensitivity of plants to changing atmospheric CO2 concentration: From the geological past to the next century', New Phytologist, vol.197, no.4, pp 1077-1094
Lewis JD, Smith RA, Ghannoum O, Logan BA, Phillips NG, Tissue DT, (2013) 'Industrial-age changes in atmospheric [CO2] and temperature differentially alter responses of faster- and slower-growing Eucalyptus seedlings to short-term drought', Tree Physiology, vol.33, no.5, pp 475-488
Sherwin GL, George L, Kannangara K, Tissue DT, Ghannoum O, (2013) 'Impact of industrial-age climate change on the relationship between water uptake and tissue nitrogen in eucalypt seedlings', Functional Plant Biology, vol.40, no.2, pp 201-212
Smith RA, Lewis JD, Ghannoum O, Tissue DT, (2012) 'Leaf structural responses to pre-industrial, current and elevated atmospheric [CO2] and temperature affect leaf function in Eucalyptus sideroxylon', Functional Plant Biology, vol.39, no.4, pp 285-296
Xu C-Y, Salih A, Ghannoum O, Tissue DT, (2012) 'Leaf structural characteristics are less important than leaf chemical properties in determining the response of leaf mass per area and photosynthesis of Eucalyptus saligna to industrial-age changes in [CO2] and temperature', Journal of Experimental Botany, vol.63, no.16, pp 5829-5841
Ghannoum O, Way DA, (2011) 'On the role of ecological adaptation and geographic distribution in the response of trees to climate change', Tree Physiology, vol.31, no.12, pp 1273-1276
Phillips NG, Attard RD, Ghannoum O, Lewis JD, Logan BA, Tissue DT, (2011) 'Impact of variable [CO2] and temperature on water transport structure-function relationships in Eucalyptus', Tree Physiology, vol.31, pp 945-952
Pinto H, Tissue DT, Ghannoum O, (2011) 'Panicum milioides (C3-C4) does not have improved water or nitrogen economies relative to C3 and C4 congeners exposed to industrial-age climate change', Journal of Experimental Botany, vol.62, pp 3223-3234
Logan BA, Hricko C, Lewis JD, Ghannoum O, Phillips NG, Smith RA, Conroy JP, Tissue DT, (2010) 'Examination of pre-industrial and future [CO2] reveals the temperature-dependent CO2 sensitivity of light energy partitioning at PSII in eucalypts', Functional Plant Biology, vol.37, pp 1041-1049
Ghannoum O, Phillips NG, Sears MA, Logan BA, Lewis JD, Conroy JP, Tissue DT, (2010) 'Photosynthetic responses of two eucalypts to industrial-age changes in atmospheric [CO2] and temperature', Plant, Cell and Environment, vol.33, pp 1671-1681
Edwards EJ, Osborne CP, Strömberg CAE, Smith SA, Bond WJ, Christin P-A, Cousins AB, Duvall MR, Fox DL, Freckleton RP, Ghannoum O, Hartwell J, Huang Y, Janis CM, Keeley JE, Kellogg EA, Knapp AK, Leakey ADB, Nelson DM, Saarela JM, Sage RF, Sala OA, Salamin N, Still CJ, Tipple B, (2010) 'The origins of C4 grasslands: Integrating evolutionary and ecosystem science', Science, vol.328, pp 587-591
Cousins AB, Ghannoum O, von Caemmerer S, Badger MR, (2010) 'Simultaneous determination of Rubisco carboxylase and oxygenase kinetic parameters in Triticum aestivum and Zea mays using membrane inlet mass spectrometry', Plant, Cell and Environment, vol.33, pp 444-452
Ghannoum O, Phillips NG, Conroy JP, Smith RA, Attard RD, Woodfield R, Logan BA, Lewis JD, Tissue DT, (2010) 'Exposure to pre-industrial, current and future atmospheric [CO2] and temperature differentially affects growth and photosynthesis in Eucalyptus', Global Change Biology, vol.16, pp 303-319
Ghannoum O, (2009) 'C4 photosynthesis and water stress', Annals of Botany, vol.103, pp 635-644 (Invited Review)
Ghannoum O, Paul MJ, Ward JL, Beale MH, Corol D-I, Conroy JP, (2008) 'The sensitivity of photosynthesis to phosphorus deficiency differs between C3 and C4 tropical grasses', Functional Plant Biology, vol.35, pp 213-221
Ghannoum O, Conroy JP, (2007) 'Phosphorus deficiency inhibits growth in parallel with photosynthesis in a C3 (Panicum laxum) but not two C4 (P. coloratum and Cenchrus ciliaris) grasses', Functional Plant Biology, vol.34, pp 72-81
Dwyer SA, Ghannoum O, Nicotra A, von Caemmerer S, (2007) 'High temperature acclimation of C4 photosynthesis is linked to changes in photosynthetic biochemistry', Plant, Cell and Environment, vol.30, pp 53-66
Ghannoum O, Evans JR, Chow WS, Andrews TJ, Conroy JP, and von Caemmerer S, (2005) 'Faster Rubisco is the key to superior nitrogen use efficiency in NADP-ME relative to NAD-ME C4 grasses', Plant Physiology, vol.137, pp 638-650
Pellny T, Ghannoum O, Conroy JP, Schluepmann H, Smeekens S, Andralojc J, Krause K-P, Goddijn O, Paul MJ, (2004) 'Genetic modification of photosynthesis with E. coli genes for trehalose synthesis', Plant Biotechnology Journal, vol.2, pp 71-82
*Siebke K, Ghannoum O, Conroy JP, Badger MR, von Caemmerer S, (2003) 'Photosynthetic oxygen exchange in C4 grasses: the role of oxygen as electron acceptor', Plant, Cell and Environment, vol.26, pp 1963-1972
*Ghannoum O, Conroy JP, Driscoll SP, Paul MJ, Foyer CH, and Lawlor DW, (2003) 'Non-stomatal limitations are responsible for drought-induced photosynthetic inhibition in four C4 grasses', New Phytologist, vol.159, pp 835-844
Siebke K, Ghannoum O, Conroy JP, von Caemmerer S, (2002) 'Elevated CO2 increases the leaf temperature of two glasshouse-grown C4 grasses', Functional Plant Biology, vol.29, pp 1377-1384
*Ghannoum O, von Caemmerer S, Conroy JP, (2002) 'The effect of drought on plant water use efficiency of 9 NAD-ME and 9 NADP-ME C4 grasses', Functional Plant Biology, vol.29, pp 1337-1348
Seneweera SP, Conroy JP, Ishimaru K, Ghannoum O, Okada M, Lieffering M, Kim H-Y, Kobayashi K, (2002) 'Changes in source-sink relations during development influence photosynthetic acclimation of rice to free-air CO2 enrichment (FACE)', Functional Plant Biology, vol.29, pp 945-953
Ghannoum O, von Caemmerer S, Conroy JP, (2001a) 'Carbon and water economy of Australian NAD-ME and NADP-ME C4 grasses', Functional Plant Biology, vol.28, pp 213-223
Ghannoum O, von Caemmerer S, Conroy JP, (2001b) 'Plant water use efficiency of 17 Australian NAD-ME and NADP-ME C4 grasses at ambient and elevated CO2 partial pressure', Functional Plant Biology, vol.28, pp 1207-1217
Seneweera SP, Ghannoum O, Conroy JP, (2001) 'Root and shoot factors contribute to the effect of drought on photosynthesis and growth of the C4 grass Panicum coloratum at elevated CO2 partial pressure', Functional Plant Biology, vol.28, pp 451-460
von Caemmerer S, Ghannoum O, Conroy JP, Clark H, Newton PCD, (2001) 'Photosynthetic responses of temperate species to free air CO2 enrichment (FACE) in a grazed New Zealand pasture', Functional Plant Biology, vol.28, pp 439-450
Ziska LH, Ghannoum O, Baker JT, Conroy J, Bunce JA, Kobayashi K, Okada M, (2001) 'A global perspective of ground level, “ambient” carbon dioxide for assessing the response of plants to atmospheric CO2', Global Change Biology, vol.7, pp 789-796
Ghannoum O, von Caemmerer S, Ziska LH, and Conroy JP, (2000) 'The growth response of C4 plants to rising atmospheric CO2 partial pressure: a reassessment', Plant, Cell and Environment, vol.23, pp 931-942 (Review)
Aben S. Seneweera S. Ghannoum O, Conroy J, (1999) 'Nitrogen requirement for maximum growth and photosynthesis of rice Oryza sativa L. cv Jarrah grown at 36 and 70 Pa CO2', Functional Plant Biology, vol.26, pp 759-766
Howden SM, McKeon GM, Walker L, Carter JO, Conroy JP, Hall WB, Ash AJ, Ghannoum O, (1999) 'Global change impacts on native pasture in south-east Queensland, Australia', Environmental Modelling & Software, vol.14, pp 307-316
Ghannoum O, Conroy JP, (1998) 'N deficiency precludes a growth response to elevated CO2 in C3 and C4 Panicum grasses', Functional Plant Biology, vol.25, pp 627-636
Ghannoum O, Siebke K, von Caemmerer S, Conroy JP, (1998) 'The photosynthesis of young C4 Panicum leaves is not C3-like', Plant, Cell and Environment, vol.9, pp 1123-1131
Seneweera SP, Ghannoum O, Conroy JP, (1998) 'High vapour pressure deficit and low soil water availability enhance shoot growth responses of a C4 grass (Panicum coloratum cv. Bambatsi) to CO2 enrichment' Functional Plant Biology, vol.25, pp 287-292
Ghannoum O, von Caemmerer S, Barlow EWR, Conroy JP, (1997) 'The Effect of CO2 enrichment and irradiance on the growth, morphology and gas exchange of a C3 (Panicum laxum) and a C4 (Panicum antidotale) grass' Functional Plant Biology, vol.24, pp 227-237
Conference Proceedings
Ghannoum O, von Caemmerer S, Conroy JP, (2001) Growth and water use efficiency of NAD-ME and NADP-ME C4 grasses exposed to a drying soil, in: Proceedings of the 12th International Congress on Photosynthesis. (Paper No. S17-006), CSIRO Publishing, Melbourne
Siebke S, Ghannoum O, Conroy JP, von Caemmerer S, (2001) Leaf temperature of C4 grasses is increased in elevated CO2 in a glasshouse, in Proceedings of the 12th International Congress on Photosynthesis. (Paper No. S32-012), CSIRO Publishing, Melbourne

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