Stomatal Response to Water Stress and its Relationship to Bulk Leaf Water Status and Osmotic Adjustment in Pearl Millet (Pennisetum americanum [L.] Leeke)

    Henson, I E and Alagarswamy, G and Mahalakshmi, V and Bidinger, F R (1982) Stomatal Response to Water Stress and its Relationship to Bulk Leaf Water Status and Osmotic Adjustment in Pearl Millet (Pennisetum americanum [L.] Leeke). Journal of Experimental Botany, 34 (4). pp. 442-450. ISSN 0022-0957

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    Abstract

    The water potential (Ψ) at which stomata completed closure (Ψ8Lmin) was determined for pearl millet (Pennisetum americanum [L.] Leeke) at two growth stages by monitoring changes in leaf conductance (gL) and Ψ following shoot detachment. Leaf water status was evaluated concurrently using a pressure-volume (P-V) technique. In a pot experiment with young vegetative plants, Ψ8Lmin closely approximated to the estimated Ψ at zero turgor (Ψu) both for control and for drought-conditioned plants which had osmotically adjusted. However, for penultimate leaves of field-grown flowering plants, Ψ8Lmin was found to be 0.61 (irrigated plants) and 0.87 (droughted plants) MPa below Ψu. In drought-stressed field-grown plants, osmotic adjustment (characterized by a decrease in solute (osmotic) potential (Ψs ) at both full hydration and zero turgor) was insufficient to maintain a positive bulk leaf turgor potential (Ψp) once Ψ had declined to below about -1.5 MPa. It is suggested that localized adjustment by the stomatal complex in response to environmental differences, leaf ageing and/or ontogenetic change, is responsible for the uncoupling of stomatal from bulk leaf water status.

    Item Type: Article
    Divisions: UNSPECIFIED
    CRP: UNSPECIFIED
    Subjects: Mandate crops > Millets
    Depositing User: Mr Charan Sai Ch
    Date Deposited: 13 Nov 2011 11:35
    Last Modified: 13 Nov 2011 11:35
    URI: http://oar.icrisat.org/id/eprint/3376
    Official URL: http://dx.doi.org/10.1093/jxb/34.4.442
    Projects: UNSPECIFIED
    Funders: UNSPECIFIED
    Acknowledgement: UNSPECIFIED
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