Reversible decreases in the bulk elastic modulus of mature leaves of deciduous Quercus species subjected to two drought treatments

Changes in leaf water relations under water stress were examined. In experiment 1, water stress was imposed by withholding irrigation to potted seedlings of deciduous oak, Quercus crispula and Q. serrata. Changes in the pressure-volume (P-V) curve in mature leaves were followed. The leaf water potential at turgor loss (Ψ l,tip ) significantly decreased after 13 d of drought treatment. The bulk elastic modulus (e) significantly decreased, which contributed to the maintenance of cell turgor together with the decrease in osmotic potential. In experiment 2, water stress was imposed by notching a branch of a Q. serrata tree. After the notching, the daily minimum leaf water potential (Ψ 1 ) decreased, and a significant decrease in Ψ l,tlp was observed 15 d after notching. The osmotic potential at water saturation (Ψ π,sat ) did not decrease significantly until 25 d after notching whereas, e had already decreased significantly within 15 d after notching and increased promptly after substantial precipitation. It was confirmed that e of mature leaves decreased reversibly in water stress. This response of e was more rapid than that of the osmotic potential and, thus, effectively maintained cell turgor when water stress was suddenly imposed on the leaves.

[1]  J. Sperry,et al.  The Effect of Reduced Hydraulic Conductance on Stomatal Conductance and Xylem Cavitation , 1993 .

[2]  N. Breda,et al.  Soil water dynamics in an oak stand , 1995, Plant and Soil.

[3]  D. White,et al.  Leaf water relations and stomatal behavior of four allopatric Eucalyptus species planted in Mediterranean southwestern Australia. , 2000, Tree physiology.

[4]  L. Fanjul,et al.  Effects of water stress on internal water relations of apple leaves , 1984 .

[5]  F. Meinzer,et al.  Effects of manipulation of water and nitrogen regime on the water relations of the desert shrub Larrea tridentata , 1988, Oecologia.

[6]  P. Schulte.  The units of currency for plant water status , 1992 .

[7]  N. Saliendra,et al.  Symplast Volume, Turgor, Stomatal Conductance and Growth in Relation to Osmotic and Elastic Adjustment in Droughted Sugarcane1 , 1991 .

[8]  S. Takagi,et al.  Cell-Wall-Dependent Organization of Actin Cytoskeleton in Vallisneria Mesophyll Cells , 2001 .

[9]  I. Terashima,et al.  Acclimation of leaf characteristics of Fagus species to previous-year and current-year solar irradiances. , 2000, Tree physiology.

[10]  H. Jones,et al.  The role of solute accumulation, osmotic adjustment and changes in cell wall elasticity in drought tolerance in Ziziphus mauritiana (Lamk.) , 1998 .

[11]  Mm Jones,et al.  Accumulation of Solutes in Leaves of Sorghum and Sunflower in Response to Water Deficits , 1980 .

[12]  J. Grace,et al.  Acclimation to Drought in Acer pseudoplatanus L. (Sycamore) Seedlings , 1992 .

[13]  T. Masaki,et al.  Community structure of a species-rich temperate forest, Ogawa Forest Reserve, central Japan , 1992, Vegetatio.

[14]  Y. Maruyama,et al.  Measurement of leaf water relations using the pressure-volume technique , 1983 .

[15]  Paul J. Kramer,et al.  Water Relations of Plants , 1983 .

[16]  H. Richter,et al.  Graphical evaluation and partitioning of turgor responses to drought in leaves of durum wheat , 1986, Planta.

[17]  U. Zimmermann,et al.  Turgor pressure changes trigger characteristic changes in the electrical conductance of the tonoplast and the plasmalemma of the marine alga Valonia utricularis , 2003 .

[18]  Melvin T. Tyree,et al.  The Measurement of the Turgor Pressure and the Water Relations of Plants by the Pressure-bomb Technique , 1972 .

[19]  P. Kramer.  13 – Drought Tolerance and Water Use Efficiency , 1983 .

[20]  M. C. Heath,et al.  Plasma Membrane–Cell Wall Adhesion Is Required for Expression of Plant Defense Responses during Fungal Penetration , 2001, Plant Cell.

[21]  Y. Matsumoto,et al.  Variations in transpiration rate and leaf cell turgor maintenance in saplings of deciduous broad-leaved tree species common in cool temperate forests in Japan. , 2003, Tree physiology.

[22]  T. Sakuratani.  Improvement of the Probe for Measuring Water Flow Rate in Intact Plants with the Stem Heat Balance Method , 1984 .

[23]  S. Takagi,et al.  Ca2+-dependent cessation of cytoplasmic streaming induced by hypertonic treatment in Vallisneria mesophyll cells: possible role of cell wall-plasma membrane adhesion. , 2003, Plant & cell physiology.

[24]  R. Joly,et al.  Alteration of Cell-Wall Water Content and Elasticity in Douglas-Fir during Periods of Water Deficit. , 1987, Plant physiology.

[25]  B. Pavlik.  Seasonal changes of osmotic pressure, symplasmic water content and tissue elasticity in the blades of dune grasses growing in situ along the coast of Oregon , 1984 .

[26]  M. Tyree,et al.  Water relations parameters on single leaves obtained in a pressure bomb and some ecological interpretations , 1975 .

[27]  M. Sobrado.  Tissue water relations and leaf growth of tropical corn cultivars under water deficits , 1986 .

[28]  A. Lakso,et al.  Diurnal and Seasonal Changes in Leaf Water Potential Components and Elastic Properties in Response to Water Stress in Apple Trees , 1979 .

[29]  Marshall,et al.  Turgor regulation via cell wall adjustment in white spruce , 1999, Plant physiology.

[30]  E. Schulze,et al.  Adaptation to water stress of the leaf water relations of four tropical forage species. , 1980 .

[31]  P. F. Scholander,et al.  Sap Pressure in Vascular Plants , 1965, Science.

[32]  T. Horiuchi,et al.  Tissue water relations of leaves of Cryptomeria japonica clones in early winter in relation to freezing resistance , 1988 .

[33]  N. Breda,et al.  Soil water dynamics in an oak stand , 1995, Plant and Soil.