Research Area: Abscisic Acid

Mesophyll cells are the main site of abscisic acid biosynthesis in water-stressed leaves

The hormone abscisic acid (ABA) plays a critical role in enhancing plant survival during water deficit. Recent molecular evidence suggests that ABA is synthesized in the phloem companion cells and guard cells. However, the nature of cell turgor…

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Leaves, not roots or floral tissue, are the main site of rapid, external pressure-induced ABA biosynthesis in angiosperms

Feng-Ping Zhang, Frances Sussmilch, David S Nichols, Amanda A Cardoso, Timothy J Brodribb, Scott A M McAdam; Leaves, not roots or floral tissue, are the main site of rapid, external pressure-induced ABA biosynthesis in angiosperms, Journal of Experimental Botany, Volume 69, Issue 5, 23 February 2018, Pages 1261–1267, https://doi.org/10.1093/jxb/erx480

Rapid biosynthesis of abscisic acid (ABA) in the leaf, triggered by a decrease in cell volume, is essential for a functional stomatal response. However, it is not known whether rapid biosynthesis of ABA is also triggered in other…

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Leaves, not roots or floral tissue, are the main site of rapid, external pressure-induced ABA biosynthesis in angiosperms

Rapid biosynthesis of abscisic acid (ABA) in the leaf, triggered by a decrease in cell volume, is essential for a functional stomatal response. However, it is not known whether rapid biosynthesis of ABA is also triggered in other…

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Abscisic acid (ABA) and key proteins in its perception and signaling pathways are ancient, but their roles have changed through time

Homologs of the Arabidopsis core abscisic acid (ABA) signaling component OPEN STOMATA1 (OST1) are best known for their role in closing stomata in angiosperm species. We recently characterized a fern OST1 homolog, GAMETOPHYTES ABA INSENSITIVE ON ANTHERDIOGEN 1…

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What are the evolutionary origins of stomatal responses to abscisic acid in land plants?

The evolution of active stomatal closure in response to leaf water deficit, mediated by the hormone abscisic acid (ABA), has been the subject of recent debate. Two different models for the timing of the evolution of this response…

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Linking auxin with photosynthetic rate via leaf venation

Scott A M McAdam, Morgane P Eléouët, Melanie Best, Timothy John Brodribb, Madeline Rose Carins Murphy, Sam David Cook, Marion Dalmais, Theodore Dimitriou, Ariane Gelinas-Marion, Warwick M Gill, Matthew Hegarty, Julie M.I. Hofer, Mary Maconochie, Erin L McAdam, Peter McGuiness, David S Nichols, John J. Ross, Frances C. Sussmilch, Shelley Urquhart (2017) Linking auxin with photosynthetic rate via leaf venation. Plant Physiology DOI: https://doi.org/10.1104/pp.17.00535

Land plants lose vast quantities of water to the atmosphere during photosynthetic gas exchange. In angiosperms a complex network of veins irrigates the leaf, and it is widely held that the density and placement of these veins determines…

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Does ozone increase ABA levels by non‐enzymatic synthesis causing stomata to close?

McAdam EL, Brodribb TJ, McAdam SAM (2017)Does ozone increase ABA levels by non‐enzymatic synthesis causing stomata to close? Plant, Cell and Environment 40: 741-747

Reactive oxygen species (ROS) are widely recognized as important regulators of stomatal aperture and plant gas exchange. The pathways through which stomata perceive ROS share many commonlinkages with the well characterized signalling pathway for the hormone abscisic acid…

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A water availability gradient reveals the deficit level required to affect traits in potted juvenile Eucalyptus globulus

McKeirnan. AB, Potts. BM, Hovenden. MJ, Brodribb. TJ, Davies. NW, Rodemann. T, McAdam. SAM, O'Reilly Wapstra. JM (2017) A water availability gradient reveals the deficit level required to affect traits in potted juvenile Eucalyptus globulus. Annals of Botany 119: 1043-1052

Drought leading to soil water deficit can have severe impacts on plants. Water deficit may lead to plant water stress and affect growth and chemical traits. Plant secondary metabolite (PSM) responses to water deficit vary between compounds and…

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An integrated hydraulic-hormonal model of conifer stomata predicts water stress dynamics

Deans, RM, Brodribb, TJ, McAdam, SAM (2017) An integrated hydraulic-hormonal model of conifer stomata predicts water stress dynamics. Plant Physiology DOI:10.1104/pp.17.00150

A simple model combining leaf hydraulics and abscisic acid 23 sensitivity can predict stomatal dynamics to short-term changes in plant water status in a conifer.

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What are the evolutionary origins of stomatal responses to abscisic acid in land plants?

Sussmilch, FC, Brodribb, TJ, McAdam, SAM (2017) What are the evolutionary origins of stomatal responses to abscisic acid in land plants? Journal of Integrative Plant Biology 59: 240-260

The evolution of active stomatal closure in response to leaf water deficit, mediated by the hormone abscisic acid (ABA), has been the subject of recent debate. Two different models for the timing of the evolution of this response…

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