Exogenous Catalase and Ascorbate Modify the Effects of Abscisic Acid (ABA) on Root Hydraulic Properties in Phaseolus vulgaris L. Plants
- 316 Downloads
Abscisic acid (ABA) modifies the hydraulic properties of roots by increasing root water flux (Jv). The role of reactive oxygen species (ROS) in this ABA-induced process was evaluated. At the same time, some antioxidant enzyme activities in root tissues were measured. Phaseolus vulgaris plants were grown hydroponically, and different concentrations of ABA in combination with catalase enzyme or ascorbate were added to the nutrient solution. Catalase treatment had no effect by itself (no ABA) and had little or only a small stimulatory effect at ABA concentrations of 1, 50, and 100 μM, but it partially inhibited the ABA effect at 5 μM. Ascorbate by itself doubled Jv and root hydraulic conductance over the control value. In the presence of ABA, ascorbate partially or, at 100 μM, completely inhibited that ABA stimulation of Jv. These results are discussed in relationship to the possibility that ABA signaling in the roots involves ROS.
KeywordsAbscisic acid Ascorbate Catalase Phaseolus vulagaris Reactive oxygen species Root water transport
The author thanks Prof. M. J. Chrispeels (University of California San Diego) for making his laboratory facilities available for these experiments, as well as for stimulating discussions and for editing the manuscript. The author was supported by a postdoctoral fellowship from the Ministerio de Educación y Ciencia (Spain). The author is also grateful to Dr. M. J. Martín for help during the experiments.
- BassiriRad H, Radin JW. 1992. Temperature-dependent water and ion transport properties of barley and sorghum roots. Plant Physiol 99:34–37Google Scholar
- Chinnusany V, Schumaker K, Zhu J-K. 2004. Molecular genetics perspectives on crosstalk and specificity in abiotic stress signalling in plants. J Exp Bot 55:225–236Google Scholar
- Collins JC, Morgan M. 1980. The influence of temperature on the abscisic acid stimulated water flow from excised maize roots. New Phytol 84:19–26Google Scholar
- Fan S, Blake TJ. 1994. Abscisic acid induced electrolyte leakage in woody species with contrasting ecological requirements. Physiol Plant 90:414–419Google Scholar
- Fernández-García N, Martínez V, Cerdá A, Carvajal M. 2002. Water and nutrient uptake of grafted tomato plants grown under saline conditions. J Plant Physiol 159:899–905Google Scholar
- Ktitorova IN, Skobeleva OV, Sharova EI, Ermakov EL. 2002. Hydrogen peroxide appears to mediate a decrease in hydraulic conductivity in wheat roots under salt stress [in Russian]. J Plant Physiol 49:369–380Google Scholar
- Markhart AH III, Fiscus EL, Naylor AW, Kramer PJ. 1979. Effect of abscisic acid on root hydraulic conductivity. Plant Physiol 64:611–614Google Scholar
- Van Breusegem F, Vranová E, Dat JF, Inzé D. 2001. The role of active oxygen species in plant signal transduction. Plant Sci 161:405–414Google Scholar
- Zhang J, Zhang X, Liang J. 1995. Exudation rate and hydraulic conductivity of maize roots are enhanced by soil drying and abscisic acid treatment. New Phytol 131:329–336Google Scholar