Does the Prostrate-leaved Geophyte Brunsvigia orientalis Utilize Soil-derived CO2 for Photosynthesis?

Michael Cramer, C. Kleizen, C. Morrow

    Research output: Contribution to journalArticle

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    Abstract

    Background and Aims A test was made of the hypothesis that the prostrate growth habit of the leaves of the geophyte Brunsvigia orientalis enables utilization of soil-derived CO2 and is related to the presence of lysigenous air-filled channels characteristic of B. orientalis leaves.Methods Brunvigia orientalis was sampled at a field site. Leaf anatomy, stomatal density, leaf/soil gas exchange characteristics and soil atmosphere and leaf delta C-13 isotope abundances were examined.Key Results The leaves of B. orientalis have large lysigenous air-filled channels separating the upper and lower surfaces of the leaves. The upper surface comprised approx. 70 % of the leaf mass and 75 % of the leaf N (mmol g(-1)). Between 20 % and 30 % of the stomatal conductance and CO2 assimilation was through the lower surface of the leaf. CO2 efflux rates from the soil surface were up to 5.4 mu mol m(-2) s(-1) while photosynthetic fluxes through the lower surface of the leaves were approx. 7 mu mol m(-2) s(-1). However, the utilization of soil-derived CO2 only altered the leaf delta C-13 isotope abundance of the prostrate leaves by a small amount. Using delta C-13 values it was estimated that 7 % of the leaf tissue C was derived from soil-derived CO2.Conclusions A small proportion of photosynthetically fixed CO2 was derived from the soil, with minimal associated transpirational H2O loss into the space between the leaf and soil. The soil-derived CO2, taken up through the lower surface was probably assimilated by the palisade tissue in the upper surface of the leaf which was exposed to sunlight and where most of the leaf N was located. The occurrence of lysigenous air channels in the leaves may provide longitudinal strength without impaired transfer of CO2 taken up through the lower surface to the upper surface.
    Original languageEnglish
    Pages (from-to)835-844
    JournalAnnals of Botany
    Volume99
    Issue number5
    DOIs
    Publication statusPublished - 2007

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    Brunsvigia
    carbon dioxide
    photosynthesis
    leaves
    soil
    soil air
    air
    isotopes

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    Cramer, Michael ; Kleizen, C. ; Morrow, C. / Does the Prostrate-leaved Geophyte Brunsvigia orientalis Utilize Soil-derived CO2 for Photosynthesis?. In: Annals of Botany. 2007 ; Vol. 99, No. 5. pp. 835-844.
    @article{fbfc6aada5bd4b3a9677b016e2e5173a,
    title = "Does the Prostrate-leaved Geophyte Brunsvigia orientalis Utilize Soil-derived CO2 for Photosynthesis?",
    abstract = "Background and Aims A test was made of the hypothesis that the prostrate growth habit of the leaves of the geophyte Brunsvigia orientalis enables utilization of soil-derived CO2 and is related to the presence of lysigenous air-filled channels characteristic of B. orientalis leaves.Methods Brunvigia orientalis was sampled at a field site. Leaf anatomy, stomatal density, leaf/soil gas exchange characteristics and soil atmosphere and leaf delta C-13 isotope abundances were examined.Key Results The leaves of B. orientalis have large lysigenous air-filled channels separating the upper and lower surfaces of the leaves. The upper surface comprised approx. 70 {\%} of the leaf mass and 75 {\%} of the leaf N (mmol g(-1)). Between 20 {\%} and 30 {\%} of the stomatal conductance and CO2 assimilation was through the lower surface of the leaf. CO2 efflux rates from the soil surface were up to 5.4 mu mol m(-2) s(-1) while photosynthetic fluxes through the lower surface of the leaves were approx. 7 mu mol m(-2) s(-1). However, the utilization of soil-derived CO2 only altered the leaf delta C-13 isotope abundance of the prostrate leaves by a small amount. Using delta C-13 values it was estimated that 7 {\%} of the leaf tissue C was derived from soil-derived CO2.Conclusions A small proportion of photosynthetically fixed CO2 was derived from the soil, with minimal associated transpirational H2O loss into the space between the leaf and soil. The soil-derived CO2, taken up through the lower surface was probably assimilated by the palisade tissue in the upper surface of the leaf which was exposed to sunlight and where most of the leaf N was located. The occurrence of lysigenous air channels in the leaves may provide longitudinal strength without impaired transfer of CO2 taken up through the lower surface to the upper surface.",
    author = "Michael Cramer and C. Kleizen and C. Morrow",
    year = "2007",
    doi = "10.1093/aob/mcm019",
    language = "English",
    volume = "99",
    pages = "835--844",
    journal = "Annals of Botany",
    issn = "0305-7364",
    publisher = "OXFORD UNIV PRESS UNITED KINGDOM",
    number = "5",

    }

    Does the Prostrate-leaved Geophyte Brunsvigia orientalis Utilize Soil-derived CO2 for Photosynthesis? / Cramer, Michael; Kleizen, C.; Morrow, C.

    In: Annals of Botany, Vol. 99, No. 5, 2007, p. 835-844.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Does the Prostrate-leaved Geophyte Brunsvigia orientalis Utilize Soil-derived CO2 for Photosynthesis?

    AU - Cramer, Michael

    AU - Kleizen, C.

    AU - Morrow, C.

    PY - 2007

    Y1 - 2007

    N2 - Background and Aims A test was made of the hypothesis that the prostrate growth habit of the leaves of the geophyte Brunsvigia orientalis enables utilization of soil-derived CO2 and is related to the presence of lysigenous air-filled channels characteristic of B. orientalis leaves.Methods Brunvigia orientalis was sampled at a field site. Leaf anatomy, stomatal density, leaf/soil gas exchange characteristics and soil atmosphere and leaf delta C-13 isotope abundances were examined.Key Results The leaves of B. orientalis have large lysigenous air-filled channels separating the upper and lower surfaces of the leaves. The upper surface comprised approx. 70 % of the leaf mass and 75 % of the leaf N (mmol g(-1)). Between 20 % and 30 % of the stomatal conductance and CO2 assimilation was through the lower surface of the leaf. CO2 efflux rates from the soil surface were up to 5.4 mu mol m(-2) s(-1) while photosynthetic fluxes through the lower surface of the leaves were approx. 7 mu mol m(-2) s(-1). However, the utilization of soil-derived CO2 only altered the leaf delta C-13 isotope abundance of the prostrate leaves by a small amount. Using delta C-13 values it was estimated that 7 % of the leaf tissue C was derived from soil-derived CO2.Conclusions A small proportion of photosynthetically fixed CO2 was derived from the soil, with minimal associated transpirational H2O loss into the space between the leaf and soil. The soil-derived CO2, taken up through the lower surface was probably assimilated by the palisade tissue in the upper surface of the leaf which was exposed to sunlight and where most of the leaf N was located. The occurrence of lysigenous air channels in the leaves may provide longitudinal strength without impaired transfer of CO2 taken up through the lower surface to the upper surface.

    AB - Background and Aims A test was made of the hypothesis that the prostrate growth habit of the leaves of the geophyte Brunsvigia orientalis enables utilization of soil-derived CO2 and is related to the presence of lysigenous air-filled channels characteristic of B. orientalis leaves.Methods Brunvigia orientalis was sampled at a field site. Leaf anatomy, stomatal density, leaf/soil gas exchange characteristics and soil atmosphere and leaf delta C-13 isotope abundances were examined.Key Results The leaves of B. orientalis have large lysigenous air-filled channels separating the upper and lower surfaces of the leaves. The upper surface comprised approx. 70 % of the leaf mass and 75 % of the leaf N (mmol g(-1)). Between 20 % and 30 % of the stomatal conductance and CO2 assimilation was through the lower surface of the leaf. CO2 efflux rates from the soil surface were up to 5.4 mu mol m(-2) s(-1) while photosynthetic fluxes through the lower surface of the leaves were approx. 7 mu mol m(-2) s(-1). However, the utilization of soil-derived CO2 only altered the leaf delta C-13 isotope abundance of the prostrate leaves by a small amount. Using delta C-13 values it was estimated that 7 % of the leaf tissue C was derived from soil-derived CO2.Conclusions A small proportion of photosynthetically fixed CO2 was derived from the soil, with minimal associated transpirational H2O loss into the space between the leaf and soil. The soil-derived CO2, taken up through the lower surface was probably assimilated by the palisade tissue in the upper surface of the leaf which was exposed to sunlight and where most of the leaf N was located. The occurrence of lysigenous air channels in the leaves may provide longitudinal strength without impaired transfer of CO2 taken up through the lower surface to the upper surface.

    U2 - 10.1093/aob/mcm019

    DO - 10.1093/aob/mcm019

    M3 - Article

    VL - 99

    SP - 835

    EP - 844

    JO - Annals of Botany

    JF - Annals of Botany

    SN - 0305-7364

    IS - 5

    ER -