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Enhancement of abscisic acid sensitivity and reduction of water consumption in Arabidopsis by combined inactivation of the protein phosphatases type 2C ABI1 and HAB1.
- Source :
-
Plant physiology [Plant Physiol] 2006 Aug; Vol. 141 (4), pp. 1389-99. Date of Electronic Publication: 2006 Jun 23. - Publication Year :
- 2006
-
Abstract
- Abscisic acid (ABA) plays a key role in plant responses to abiotic stress, particularly drought stress. A wide number of ABA-hypersensitive mutants is known, however, only a few of them resist/avoid drought stress. In this work we have generated ABA-hypersensitive drought-avoidant mutants by simultaneous inactivation of two negative regulators of ABA signaling, i.e. the protein phosphatases type 2C (PP2Cs) ABA-INSENSITIVE1 (ABI1) and HYPERSENSITIVE TO ABA1 (HAB1). Two new recessive loss-of-function alleles of ABI1, abi1-2 and abi1-3, were identified in an Arabidopsis (Arabidopsis thaliana) T-DNA collection. These mutants showed enhanced responses to ABA both in seed and vegetative tissues, but only a limited effect on plant drought avoidance. In contrast, generation of double hab1-1 abi1-2 and hab1-1 abi1-3 mutants strongly increased plant responsiveness to ABA. Thus, both hab1-1 abi1-2 and hab1-1 abi1-3 were particularly sensitive to ABA-mediated inhibition of seed germination. Additionally, vegetative responses to ABA were reinforced in the double mutants, which showed a strong hypersensitivity to ABA in growth assays, stomatal closure, and induction of ABA-responsive genes. Transpirational water loss under drought conditions was noticeably reduced in the double mutants as compared to single parental mutants, which resulted in reduced water consumption of whole plants. Taken together, these results reveal cooperative negative regulation of ABA signaling by ABI1 and HAB1 and suggest that fine tuning of ABA signaling can be attained through combined action of PP2Cs. Finally, these results suggest that combined inactivation of specific PP2Cs involved in ABA signaling could provide an approach for improving crop performance under drought stress conditions.
- Subjects :
- Arabidopsis genetics
Arabidopsis metabolism
Arabidopsis Proteins genetics
Arabidopsis Proteins physiology
Mutation
Phosphoprotein Phosphatases genetics
Phosphoprotein Phosphatases physiology
Plant Leaves anatomy & histology
Plant Leaves metabolism
Plant Leaves physiology
Plant Transpiration physiology
Signal Transduction
Abscisic Acid pharmacology
Arabidopsis enzymology
Arabidopsis Proteins metabolism
Phosphoprotein Phosphatases metabolism
Water metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0032-0889
- Volume :
- 141
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Plant physiology
- Publication Type :
- Academic Journal
- Accession number :
- 16798945
- Full Text :
- https://doi.org/10.1104/pp.106.081018