Journal of Experimental Botany, Vol. 53, No. 367, pp. 251-263,
February 1, 2002
© 2002 Oxford University Press
Original Papers |
Drought-induced changes in xylem pH, ionic composition, and ABA concentration act as early signals in field-grown maize (Zea mays L.)
1 The Royal Veterinary and Agricultural University, Department of Agricultural Sciences, Laboratory for Agrohydrology and Bioclimatology, Agrovej 10, DK-2630 Taastrup, Denmark
2 Rheinische Friedrich-Wilhelms-Universiät Bonn, Landwirtschaftliche Fakultät, Agrikulturchemisches Institut, Karlrobert-Kreiten-Strasse 13, 53115 Bonn, Germany
3 Fakultas Pertanian, Universitas Haluoleo, Kampus Bumi Tridharma, Anduonohu, Kendari 93232, Indonesia
Early signals potentially regulating leaf growth and stomatal aperture in field-grown maize (Zea mays L.) subjected to drought were investigated. Plants grown in a field lysimeter on two soil types were subjected to progressive drought during vegetative growth. Leaf ABA content, water status, extension rate, conductance, photosynthesis, nitrogen content, and xylem sap composition were measured daily. Maize responded similarly to progressive drought on both soil types. Effects on loam were less pronounced than on sand. Relative to fully-watered controls, xylem pH increased by about 0.2 units one day after withholding irrigation (DAWI) and conductivity decreased by about 0.25 mS cm-1 1–3 DAWI. Xylem nitrate, ammonium, and phosphate concentrations decreased by about 50% at 1–5 DAWI and potassium concentration decreased by about 50% at 7–8 DAWI. Xylem ABA concentration consistently increased by 45–70 pmol ml-1 at 7 DAWI. Leaf extension rate decreased 5 DAWI, after the changes in xylem chemical composition had occurred. Leaf nitrogen significantly decreased 8–16 DAWI in droughted plants. Midday leaf water potential and photosynthesis were significantly decreased in droughted plants late in the drying period. Xylem nitrate concentration was the only ionic xylem sap component significantly correlated to increasing soil moisture deficit and decreasing leaf nitrogen concentration. Predawn leaf ABA content in droughted plants increased by 100–200 ng g-1 dry weight at 7 DAWI coinciding with a decrease in stomatal conductance before any significant decrease in midday leaf water potential was observed. Based on the observed sequence, a chain of signal events is suggested eventually leading to stomatal closure and leaf surface reduction through interactive effects of reduced nitrogen supply and plant growth regulators under drought.
Key words: Abscisic acid, drought, nitrate, pH, root–shoot communication, xylem sap composition.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  R. G. Sharp and W. J. Davies Variability among species in the apoplastic pH signalling response to drying soils J. Exp. Bot., November 1, 2009; 60(15): 4363 - 4370. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Volaire, G. Seddaiu, L. Ledda, and F. Lelievre Water deficit and induction of summer dormancy in perennial Mediterranean grasses Ann. Bot., June 1, 2009; 103(8): 1337 - 1346. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Wilkinson and W. J. Davies Manipulation of the apoplastic pH of intact plants mimics stomatal and growth responses to water availability and microclimatic variation J. Exp. Bot., February 13, 2008; (2008) erm338v1. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Rezaei Nejad and U. van Meeteren Dynamics of adaptation of stomatal behaviour to moderate or high relative air humidity in Tradescantia virginiana J. Exp. Bot., February 1, 2008; 59(2): 289 - 301. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Wilkinson, M. A. Bacon, and W. J. Davies Nitrate signalling to stomata and growing leaves: interactions with soil drying, ABA, and xylem sap pH in maize J. Exp. Bot., May 1, 2007; 58(7): 1705 - 1716. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. R. Nejad and U. van Meeteren The role of abscisic acid in disturbed stomatal response characteristics of Tradescantia virginiana during growth at high relative air humidity J. Exp. Bot., February 1, 2007; 58(3): 627 - 636. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Liu, A. Shahnazari, M. N. Andersen, S.-E. Jacobsen, and C. R. Jensen Physiological responses of potato (Solanum tuberosum L.) to partial root-zone drying: ABA signalling, leaf gas exchange, and water use efficiency J. Exp. Bot., November 1, 2006; 57(14): 3727 - 3735. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Q. D. Goodger, R. E. Sharp, E. L. Marsh, and D. P. Schachtman Relationships between xylem sap constituents and leaf conductance of well-watered and water-stressed maize across three xylem sap sampling techniques J. Exp. Bot., September 1, 2005; 56(419): 2389 - 2400. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Y. Sobeih, I. C. Dodd, M. A. Bacon, D. Grierson, and W. J. Davies Long-distance signals regulating stomatal conductance and leaf growth in tomato (Lycopersicon esculentum) plants subjected to partial root-zone drying J. Exp. Bot., November 1, 2004; 55(407): 2353 - 2363. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. DaCosta, Z. Wang, and B. Huang Physiological Adaptation of Kentucky Bluegrass to Localized Soil Drying Crop Sci., July 1, 2004; 44(4): 1307 - 1314. [Abstract] [Full Text] [PDF]
|
|