How Do Roots Control Xylem Sap ABA Concentration in Response to Soil Drying

Maize (Zea mays L.) and Leucaena leucocephala (a tropical tree) were subjected to different degrees of soil drying and changes in their root and xylem ABA concentrations were measured simultaneously. Additional treatments such as defoliation, light sheltering and stem girdling were applied so that phloem transport into roots was manipulated. When soil was dried, ABA concentration in xylem sap increased almost linearly with that of roots in both species. Such an increase was relatively plateaued at high root ABA concentrations, suggesting that severe soil drying might have hindered some parts of roots from delivering ABA into xylem flow. When 3 H-ABA was load

[1]  Jianhua Zhang,et al.  Sequential response of whole plant water relations to prolonged soil drying and the involvement of xylem sap ABA in the regulation of stomatal behaviour of sunflower plants , 1989 .

[2]  Jianhua Zhang,et al.  Relative Contribution of Apices and Mature Tissues to ABA Synthesis in Droughted Maize Root Systems , 1996 .

[3]  Jianhua Zhang,et al.  Stomatal conductance in relation to xylem sap abscisic acid concentrations in two tropical trees, Acacia confusa and Litsea glutinosa , 1996 .

[4]  John Grace,et al.  Does Xylem Sap ABA Control the Stomatal Behaviour of Water-Stressed Sycamore (Acer pseudoplatanus L.) Seedlings? , 1993 .

[5]  Jianhua Zhang,et al.  Does ABA in the Xylem Control the Rate of Leaf Growth in Soil-Dried Maize and Sunflower Plants? , 1990 .

[6]  R. Munns,et al.  Stored xylem sap from wheat and barley in drying soil contains a transpiration inhibitor with a large molecular size , 1993 .

[7]  Jianhua Zhang,et al.  Does abscisic acid play a stress physiological role in maize plants growing in heavily compacted soil , 1994 .

[8]  J. Pereira,et al.  The control of leaf conductance of white lupin by xylem ABA concentration decreases with the severity of water deficits , 1995 .

[9]  W. Hartung,et al.  The pH gradients in the root system and the abscisic acid concentration in xylem and apoplastic saps , 1993 .

[10]  H. Meidner.  Our Understanding of Plant Water RelationsThe Bidder Lecture delivered at the Hull Meeting of the Society of Experimental Biology on 7 April 1983 , 1983 .

[11]  Jianhua Zhang,et al.  Changes in the concentration of ABA in xylem sap as a function of changing soil water status can account for changes in leaf conductance and growth , 1990 .

[12]  Jianhua Zhang.  Accumulation of ABA in maize roots in response to root severing. , 1994, The New phytologist.

[13]  W. Davies,et al.  Drought-induced Closure of Phaseolus vulgaris L. Stomata Precedes Leaf Water Deficit and any Increase in Xylem ABA Concentration , 1991 .

[14]  W. Hartung,et al.  Long Distance Transport of Abscisic Acid in NaCI-Treated Intact Plants of Lupinus albus , 1990 .

[15]  K. Cornish,et al.  Abscisic Acid Metabolism in Relation to Water Stress and Leaf Age in Xanthium strumarium. , 1984, Plant physiology.

[16]  John Grace,et al.  Abscisic acid concentrations and fluxes in droughted conifer saplings , 1995 .

[17]  A. L. McLeod,et al.  Do leaves contribute to the abscisic acid present in the xylem sap of ‘draughted’ sunflower plants? , 1991 .

[18]  William J. Davies,et al.  Xylem‐transported abscisic acid: the relative importance of its mass and its concentration in the control of stomatal aperture , 1993 .

[19]  Jianhua Zhang,et al.  Abscisic acid produced in dehydrating roots may enable the plant to measure the water status of the soil , 1989 .

[20]  Jianhua Zhang,et al.  Can early wilting of old leaves account for much of the ABA accumulation in flooded pea plants , 1994 .

[21]  J. Pereira,et al.  Abscisic acid in apoplastic sap can account for the restriction in leaf conductance of white lupins during moderate soil drying and after rewatering , 1994 .

[22]  William J. Davies,et al.  Root Signals and the Regulation of Growth and Development of Plants in Drying Soil , 1991 .

[23]  R. Munns,et al.  Abscisic Acid is not the only stomatal inhibitor in the transpiration stream of wheat plants. , 1988, Plant physiology.

[24]  O. Bethenod,et al.  Xylem ABA controls the stomatal conductance of field‐grown maize subjected to soil compaction or soil drying , 1992 .

[25]  Jianhua Zhang,et al.  Metabolism of xylem-delivered ABA in relation to ABA flux and concentration in leaves of maize and Commelina communis , 1996 .