ISSN:
1432-2048
Keywords:
Abscisic acid (ABA)
;
Leaf water potential
;
Phaseic acid
;
Phaseolus
;
Stomates
;
Water stress
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Leaf water potentials of Phaseolus vulgaris L. plants exposed to a -3.0 bar root medium were reduced to between -7 and -9 bars within 25 min and remained constant for the next several hours. This treatment led to considerable variation between leaves in both abscisic-acid (ABA) content and Rs, although the two were well correlated after a 5-h treatment. There was an apparent 7-fold increase in leaf ABA levels necessary to initiate stomatal closure when plants were exposed to a -3.0 bar treatment, but when plants were exposed to a -5.0 bar stress Rs values increased prior to any detectable rise in ABA levels. To explain these seemingly contradictory results, we suggest that the rate of ABA synthesis in the leaf, rather than the total ABA content, determines the status of the stomatal aperture.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00391912
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