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 [CO 2] and temperature

Xu, Cheng-Yuan and Salih, Anya and Ghannoum, Oula and Tissue, David T. (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 [CO 2] and temperature. Journal of Experimental Botany, 63 (16). pp. 5829-5841. ISSN 0022-0957

Abstract

The rise in atmospheric [CO 2] is associated with increasing air temperature. However, studies on plant responses to interactive effects of [CO 2] and temperature are limited, particularly for leaf structural attributes. In this study, Eucalyptus saligna plants were grown in sun-lit glasshouses differing in [CO 2] (290, 400, and 650 mol mol -1) and temperature (26 °C and 30 °C). Leaf anatomy and chloroplast parameters were assessed with three-dimensional confocal microscopy, and the interactive effects of [CO 2] and temperature were quantified. The relative influence of leaf structural attributes and chemical properties on the variation of leaf mass per area (LMA) and photosynthesis within these climate regimes was also determined. Leaf thickness and mesophyll size increased in higher [CO 2] but decreased at the warmer temperature; no treatment interaction was observed. In pre-industrial [CO 2], warming reduced chloroplast diameter without altering chloroplast number per cell, but the opposite pattern (reduced chloroplast number per cell and unchanged chloroplast diameter) was observed in both current and projected [CO 2]. The variation of LMA was primarily explained by total non-structural carbohydrate (TNC) concentration rather than leaf thickness. Leaf photosynthetic capacity (light- and [CO 2]-saturated rate at 28 °C) and light-saturated photosynthesis (under growth [CO 2] and temperature) were primarily determined by leaf nitrogen contents, while secondarily affected by chloroplast gas exchange surface area and chloroplast number per cell, respectively. In conclusion, leaf structural attributes are less important than TNC and nitrogen in affecting LMA and photosynthesis responses to the studied climate regimes, indicating that leaf structural attributes have limited capacity to adjust these functional traits in a changing climate.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Copyright © 2012 The authors. Permanent restricted access to published version, due to publisher's copyright policy (OUP)
Depositing User: epEditor USQ
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 06 Dec 2012 05:38
Last Modified: 03 Jul 2013 01:32
Uncontrolled Keywords: chloroplast; climate change; confocal microscopy; elevated [CO 2]; global warming; leaf anatomy; leaf morphology; photosynthesis
Fields of Research (FOR2008): 06 Biological Sciences > 0607 Plant Biology > 060705 Plant Physiology
06 Biological Sciences > 0603 Evolutionary Biology > 060303 Biological Adaptation
05 Environmental Sciences > 0501 Ecological Applications > 050101 Ecological Impacts of Climate Change
Socio-Economic Objective (SEO2008): D Environment > 96 Environment > 9603 Climate and Climate Change > 960307 Effects of Climate Change and Variability on Australia (excl. Social Impacts)
Identification Number or DOI: doi: 10.1093/jxb/ers231
URI: http://eprints.usq.edu.au/id/eprint/22210

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