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Modulation of drought resistance by the abscisic acid receptor PYL5 through inhibition of clade A PP2Cs.
- Source :
-
The Plant journal : for cell and molecular biology [Plant J] 2009 Nov; Vol. 60 (4), pp. 575-88. Date of Electronic Publication: 2009 Jul 16. - Publication Year :
- 2009
-
Abstract
- Abscisic acid (ABA) is a key phytohormone involved in adaption to environmental stress and regulation of plant development. Clade A protein phosphatases type 2C (PP2Cs), such as HAB1, are key negative regulators of ABA signaling in Arabidopsis. To obtain further insight into regulation of HAB1 function by ABA, we have screened for HAB1-interacting partners using a yeast two-hybrid approach. Three proteins were identified, PYL5, PYL6 and PYL8, which belong to a 14-member subfamily of the Bet v1-like superfamily. HAB1-PYL5 interaction was confirmed using BiFC and co-immunoprecipitation assays. PYL5 over-expression led to a globally enhanced response to ABA, in contrast to the opposite phenotype reported for HAB1-over-expressing plants. F(2) plants that over-expressed both HAB1 and PYL5 showed an enhanced response to ABA, indicating that PYL5 antagonizes HAB1 function. PYL5 and other members of its protein family inhibited HAB1, ABI1 and ABI2 phosphatase activity in an ABA-dependent manner. Isothermal titration calorimetry revealed saturable binding of (+)ABA to PYL5, with K(d) values of 1.1 mum or 38 nm in the absence or presence of the PP2C catalytic core of HAB1, respectively. Our work indicates that PYL5 is a cytosolic and nuclear ABA receptor that activates ABA signaling through direct inhibition of clade A PP2Cs. Moreover, we show that enhanced resistance to drought can be obtained through PYL5-mediated inhibition of clade A PP2Cs.
- Subjects :
- Arabidopsis enzymology
Arabidopsis Proteins genetics
Droughts
Gene Expression Regulation, Plant
Phosphoprotein Phosphatases genetics
Protein Phosphatase 2C
RNA, Plant genetics
Recombinant Proteins genetics
Recombinant Proteins metabolism
Signal Transduction
Abscisic Acid pharmacology
Arabidopsis genetics
Arabidopsis Proteins metabolism
Phosphoprotein Phosphatases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1365-313X
- Volume :
- 60
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- The Plant journal : for cell and molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 19624469
- Full Text :
- https://doi.org/10.1111/j.1365-313X.2009.03981.x