Culm sucrose accumulation promotes physiological decline of mature leaves in ripening sugarcane

A.J. Mccormick, Michael Cramer, D.A. Watt

    Research output: Contribution to journalArticle

    20 Citations (Scopus)

    Abstract

    Photosynthetic activity in C4 sugarcane has been suggested to be regulated by the demand for photoassimilate from sink tissues, including culm storage of sucrose and other components of the plant (e.g. roots and shoot primordia). This study examined the extent to which sink-demand influences leaf photosynthetic activity and controls leaf turnover in field-grown sugarcane. To increase sink-demand on selected leaves, plants were defoliated apart from the immature leaf before the first fully expanded leaf (2nd leaf) and the mature 8th leaf. Changes in leaf gas exchange and fluorescence characteristics were recorded for both leaves over a 28 d period. Variations in leaf and culm sucrose and hexose concentrations and allocation of 14C-labelled photosynthate were also measured. A decrease in culm internodal sucrose concentrations in partially defoliated plants was associated with significant increases in assimilation (A) and electron transport rates (ETR) for both leaves 2 and 8. Conversely, accumulation of sucrose in the culms of control plants was related to a decline in photosynthetic rates in leaf 8 during the treatment period. Leaves 2 and 8 of defoliated plants (27 d) were characterised by an increase in partitioning of 14C to mature and immature internodes, respectively, compared to control plants. In addition, hexose levels in leaves of defoliated plants decreased significantly (36% and 48% decrease in leaves 2 and 8, respectively) compared to corresponding leaves of untreated controls over the duration of the experiment, indicating that the signaling mechanisms regulating the decline in leaf photosynthetic activity are likely hexose-mediated. It was concluded that leaf physiological ageing in sugarcane was promoted by sucrose accumulation during culm maturation as a consequence of decreased sink-demand for photosynthate.
    Original languageEnglish
    Pages (from-to)250-258
    JournalField Crops Research
    Volume108
    Issue number3
    DOIs
    Publication statusPublished - 2008

    Fingerprint

    ripening
    sucrose
    sugarcane
    leaves
    hexoses
    photosynthates
    immatures
    shoot primordia
    root primordia

    Cite this

    Mccormick, A.J. ; Cramer, Michael ; Watt, D.A. / Culm sucrose accumulation promotes physiological decline of mature leaves in ripening sugarcane. In: Field Crops Research. 2008 ; Vol. 108, No. 3. pp. 250-258.
    @article{8540e566ec9444a5be31916bbc94ca4c,
    title = "Culm sucrose accumulation promotes physiological decline of mature leaves in ripening sugarcane",
    abstract = "Photosynthetic activity in C4 sugarcane has been suggested to be regulated by the demand for photoassimilate from sink tissues, including culm storage of sucrose and other components of the plant (e.g. roots and shoot primordia). This study examined the extent to which sink-demand influences leaf photosynthetic activity and controls leaf turnover in field-grown sugarcane. To increase sink-demand on selected leaves, plants were defoliated apart from the immature leaf before the first fully expanded leaf (2nd leaf) and the mature 8th leaf. Changes in leaf gas exchange and fluorescence characteristics were recorded for both leaves over a 28 d period. Variations in leaf and culm sucrose and hexose concentrations and allocation of 14C-labelled photosynthate were also measured. A decrease in culm internodal sucrose concentrations in partially defoliated plants was associated with significant increases in assimilation (A) and electron transport rates (ETR) for both leaves 2 and 8. Conversely, accumulation of sucrose in the culms of control plants was related to a decline in photosynthetic rates in leaf 8 during the treatment period. Leaves 2 and 8 of defoliated plants (27 d) were characterised by an increase in partitioning of 14C to mature and immature internodes, respectively, compared to control plants. In addition, hexose levels in leaves of defoliated plants decreased significantly (36{\%} and 48{\%} decrease in leaves 2 and 8, respectively) compared to corresponding leaves of untreated controls over the duration of the experiment, indicating that the signaling mechanisms regulating the decline in leaf photosynthetic activity are likely hexose-mediated. It was concluded that leaf physiological ageing in sugarcane was promoted by sucrose accumulation during culm maturation as a consequence of decreased sink-demand for photosynthate.",
    author = "A.J. Mccormick and Michael Cramer and D.A. Watt",
    year = "2008",
    doi = "10.1016/j.fcr.2008.06.004",
    language = "English",
    volume = "108",
    pages = "250--258",
    journal = "Field Crop Research",
    issn = "0378-4290",
    publisher = "Pergamon",
    number = "3",

    }

    Culm sucrose accumulation promotes physiological decline of mature leaves in ripening sugarcane. / Mccormick, A.J.; Cramer, Michael; Watt, D.A.

    In: Field Crops Research, Vol. 108, No. 3, 2008, p. 250-258.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Culm sucrose accumulation promotes physiological decline of mature leaves in ripening sugarcane

    AU - Mccormick, A.J.

    AU - Cramer, Michael

    AU - Watt, D.A.

    PY - 2008

    Y1 - 2008

    N2 - Photosynthetic activity in C4 sugarcane has been suggested to be regulated by the demand for photoassimilate from sink tissues, including culm storage of sucrose and other components of the plant (e.g. roots and shoot primordia). This study examined the extent to which sink-demand influences leaf photosynthetic activity and controls leaf turnover in field-grown sugarcane. To increase sink-demand on selected leaves, plants were defoliated apart from the immature leaf before the first fully expanded leaf (2nd leaf) and the mature 8th leaf. Changes in leaf gas exchange and fluorescence characteristics were recorded for both leaves over a 28 d period. Variations in leaf and culm sucrose and hexose concentrations and allocation of 14C-labelled photosynthate were also measured. A decrease in culm internodal sucrose concentrations in partially defoliated plants was associated with significant increases in assimilation (A) and electron transport rates (ETR) for both leaves 2 and 8. Conversely, accumulation of sucrose in the culms of control plants was related to a decline in photosynthetic rates in leaf 8 during the treatment period. Leaves 2 and 8 of defoliated plants (27 d) were characterised by an increase in partitioning of 14C to mature and immature internodes, respectively, compared to control plants. In addition, hexose levels in leaves of defoliated plants decreased significantly (36% and 48% decrease in leaves 2 and 8, respectively) compared to corresponding leaves of untreated controls over the duration of the experiment, indicating that the signaling mechanisms regulating the decline in leaf photosynthetic activity are likely hexose-mediated. It was concluded that leaf physiological ageing in sugarcane was promoted by sucrose accumulation during culm maturation as a consequence of decreased sink-demand for photosynthate.

    AB - Photosynthetic activity in C4 sugarcane has been suggested to be regulated by the demand for photoassimilate from sink tissues, including culm storage of sucrose and other components of the plant (e.g. roots and shoot primordia). This study examined the extent to which sink-demand influences leaf photosynthetic activity and controls leaf turnover in field-grown sugarcane. To increase sink-demand on selected leaves, plants were defoliated apart from the immature leaf before the first fully expanded leaf (2nd leaf) and the mature 8th leaf. Changes in leaf gas exchange and fluorescence characteristics were recorded for both leaves over a 28 d period. Variations in leaf and culm sucrose and hexose concentrations and allocation of 14C-labelled photosynthate were also measured. A decrease in culm internodal sucrose concentrations in partially defoliated plants was associated with significant increases in assimilation (A) and electron transport rates (ETR) for both leaves 2 and 8. Conversely, accumulation of sucrose in the culms of control plants was related to a decline in photosynthetic rates in leaf 8 during the treatment period. Leaves 2 and 8 of defoliated plants (27 d) were characterised by an increase in partitioning of 14C to mature and immature internodes, respectively, compared to control plants. In addition, hexose levels in leaves of defoliated plants decreased significantly (36% and 48% decrease in leaves 2 and 8, respectively) compared to corresponding leaves of untreated controls over the duration of the experiment, indicating that the signaling mechanisms regulating the decline in leaf photosynthetic activity are likely hexose-mediated. It was concluded that leaf physiological ageing in sugarcane was promoted by sucrose accumulation during culm maturation as a consequence of decreased sink-demand for photosynthate.

    U2 - 10.1016/j.fcr.2008.06.004

    DO - 10.1016/j.fcr.2008.06.004

    M3 - Article

    VL - 108

    SP - 250

    EP - 258

    JO - Field Crop Research

    JF - Field Crop Research

    SN - 0378-4290

    IS - 3

    ER -