Temporal heterogeneity of cold acclimation phenotypes in Arabidopsis leaves

Authors

  • PETER A. GORSUCH,

    1. Department of Biology, University of York, PO Box 373, York YO10 5YW, UK,
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  • SUBEDAR PANDEY,

    1. CNAP Research Laboratories, Department of Biology, University of York, Heslington, PO Box 373, York, YO10 5YW, UK and
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  • OWEN K. ATKIN

    Corresponding author
    1. Department of Biology, University of York, PO Box 373, York YO10 5YW, UK,
    2. Functional Ecology Group, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
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O. K. Atkin, Functional Ecology Group, Research School of Biology, Building 46, The Australian National University, Canberra, ACT 2601, Australia. Fax: +61 1904 432 860; e-mail: owen.atkin@anu.edu.au

ABSTRACT

To predict the effects of temperature changes on plant growth and performance, it is crucial to understand the impact of thermal history on leaf morphology, anatomy and physiology. Here, we document a comprehensive range of leaf phenotypes in 25/20 °C-grown Arabidopsis thaliana plants that were shifted to 5 °C for up to 2 months. When warm-grown, pre-existing (PE) leaves were exposed to cold, leaf thickness increased due to an increase in mesophyll cell size. Leaves that were entirely cold-developed (CD) were twice as thick (eight cell layers) as their warm-developed (WD) counterparts (six layers), and also had higher epidermal and stomatal cell densities. After 4 d of cold, PE leaves accumulated high levels of total non-structural carbohydrates (TNC). However, glucose and starch levels declined thereafter, and after 45 d in the cold, PE leaves exhibited similar TNC to CD leaves. A similar phenomenon was observed in δ13C and a range of photosynthetic parameters. In cold-treated PE leaves, an increase in respiration (Rdark) with cold exposure time was evident when measured at 25 °C but not 5 °C. Cold acclimation was associated with a large increase in the ratio of leaf Rdark to photosynthesis. The data highlight the importance of understanding developmental thermal history in determining individual phenotypic traits.

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