Fluorescence imaging application: Effect of leaf age on seagrass photokinetics

Ralph, PJ; Macinnis-Ng, CMO; Frankart, C

Fluorescence imaging application: Effect of leaf age on seagrass photokinetics

Ralph, PJ

Macinnis-Ng, CMO

Frankart, C

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Publication Type:: Journal Article
Citation:: Aquatic Botany, 2005, 81 (1), pp. 69 - 84
Issue Date:: 2005-01-01

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Field	Value	Language
dc.contributor.author	Ralph, PJ https://orcid.org/0000-0002-3103-7346	en_US
dc.contributor.author	Macinnis-Ng, CMO https://orcid.org/0000-0003-3935-9814	en_US
dc.contributor.author	Frankart, C	en_US
dc.date.issued	2005-01-01	en_US
dc.identifier.citation	Aquatic Botany, 2005, 81 (1), pp. 69 - 84	en_US
dc.identifier.issn	0304-3770	en_US
dc.identifier.uri	http://hdl.handle.net/10453/3803
dc.description.abstract	We used the Imaging-PAM fluorometer to map spatial variability of photosynthesis in three seagrass species, Halophila ovalis, Zostera capricorni and Posidonia australis. Photosynthesis was described by relative photosynthetic rate (PS/50), effective quantum yield (ΦPSII), non-photochemical quenching (NPQ and qN), electron transport rate (ETR) and leaf absorptivity. Photosynthetic patterns were linked to leaf age and light climate but patterns were not consistent across species. Longitudinal heterogeneity in photosynthesis was apparent along the leaves of all three species while lateral spatial heterogeneity was found only across Z. capricorni and H. ovalis leaves. Age of leaf tissue, determined by longitudinal location on the leaf, strongly influenced photosynthetic activity of Z. capricorni and P. australis. A comparison of H. ovalis leaves of differing maturity demonstrated the influence of leaf age on photosynthetic activity, yet a comparison of Z. capricorni leaves of differing maturity showed no leaf-age effects. Variations in stress-induced changes across a seagrass leaf can be used to identify areas or particular regions of the leaf, which are more susceptible to photodamage. Clear evidence of substantial within-leaf heterogeneity in photosynthetic activity (i.e., a two-fold variation in half saturation constant along a leaf of P. australis) has serious implications for use of small sections of leaf for photosynthetic incubations (such as O2 or single-point chlorophyll a fluorescence measurements). © 2004 Elsevier B.V. All rights reserved.	en_US
dc.relation.ispartof	Aquatic Botany	en_US
dc.relation.isbasedon	10.1016/j.aquabot.2004.11.003	en_US
dc.subject.classification	Marine Biology & Hydrobiology	en_US
dc.title	Fluorescence imaging application: Effect of leaf age on seagrass photokinetics	en_US
dc.type	Journal Article
utslib.citation.volume	1	en_US
utslib.citation.volume	81	en_US
utslib.for	060701 Phycology (incl. Marine Grasses)	en_US
utslib.for	0502 Environmental Science and Management	en_US
utslib.for	0602 Ecology	en_US
utslib.for	0607 Plant Biology	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Strength - C3 - Climate Change Cluster
utslib.copyright.status	closed_access
pubs.issue	1	en_US
pubs.publication-status	Published	en_US
pubs.volume	81	en_US

Abstract:

We used the Imaging-PAM fluorometer to map spatial variability of photosynthesis in three seagrass species, Halophila ovalis, Zostera capricorni and Posidonia australis. Photosynthesis was described by relative photosynthetic rate (PS/50), effective quantum yield (ΦPSII), non-photochemical quenching (NPQ and qN), electron transport rate (ETR) and leaf absorptivity. Photosynthetic patterns were linked to leaf age and light climate but patterns were not consistent across species. Longitudinal heterogeneity in photosynthesis was apparent along the leaves of all three species while lateral spatial heterogeneity was found only across Z. capricorni and H. ovalis leaves. Age of leaf tissue, determined by longitudinal location on the leaf, strongly influenced photosynthetic activity of Z. capricorni and P. australis. A comparison of H. ovalis leaves of differing maturity demonstrated the influence of leaf age on photosynthetic activity, yet a comparison of Z. capricorni leaves of differing maturity showed no leaf-age effects. Variations in stress-induced changes across a seagrass leaf can be used to identify areas or particular regions of the leaf, which are more susceptible to photodamage. Clear evidence of substantial within-leaf heterogeneity in photosynthetic activity (i.e., a two-fold variation in half saturation constant along a leaf of P. australis) has serious implications for use of small sections of leaf for photosynthetic incubations (such as O2 or single-point chlorophyll a fluorescence measurements). © 2004 Elsevier B.V. All rights reserved.

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http://hdl.handle.net/10453/3803