Arabidopsis ABA Receptor RCAR1/PYL9 Interacts with an R2R3-Type MYB Transcription Factor, AtMYB44
AbstractAbscisic acid (ABA) signaling plays important roles in plant growth, development and adaptation to various stresses. RCAR1/PYL9 has been known as a cytoplasm and nuclear ABA receptor in Arabidopsis. To obtain further insight into the regulatory mechanism of RCAR1/PYL9, a yeast two-hybrid approach was performed to screen for RCAR1/PYL9-interacting proteins and an R2R3-type MYB transcription factor, AtMYB44, was identified. The interaction between RCAR1/PYL9 and AtMYB44 was further confirmed by glutathione S-transferase (GST) pull-down and bimolecular fluorescence complementation (BiFC) assays. Gene expression analysis showed that AtMYB44 negatively regulated the expression of ABA-responsive gene RAB18, in contrast to the opposite role reported for RCAR1/PYL9. Competitive GST pull-down assay and analysis of phosphatase activity demonstrated that AtMYB44 and ABI1 competed for binding to RCAR1/PYL9 and thereby reduced the inhibitory effect of RCAR1/PYL9 on ABI1 phosphatase activity in the presence of ABA in vitro. Furthermore, transient activation assay in protoplasts revealed AtMYB44 probably also decreased RCAR1/PYL9-mediated inhibition of ABI1 activity in vivo. Taken together, our work provides a reasonable molecular mechanism of AtMYB44 in ABA signaling. View Full-Text
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Li, D.; Li, Y.; Zhang, L.; Wang, X.; Zhao, Z.; Tao, Z.; Wang, J.; Wang, J.; Lin, M.; Li, X.; Yang, Y. Arabidopsis ABA Receptor RCAR1/PYL9 Interacts with an R2R3-Type MYB Transcription Factor, AtMYB44. Int. J. Mol. Sci. 2014, 15, 8473-8490.
Li D, Li Y, Zhang L, Wang X, Zhao Z, Tao Z, Wang J, Wang J, Lin M, Li X, Yang Y. Arabidopsis ABA Receptor RCAR1/PYL9 Interacts with an R2R3-Type MYB Transcription Factor, AtMYB44. International Journal of Molecular Sciences. 2014; 15(5):8473-8490.Chicago/Turabian Style
Li, Dekuan; Li, Ying; Zhang, Liang; Wang, Xiaoyu; Zhao, Zhe; Tao, Zhiwen; Wang, Jianmei; Wang, Jin; Lin, Min; Li, Xufeng; Yang, Yi. 2014. "Arabidopsis ABA Receptor RCAR1/PYL9 Interacts with an R2R3-Type MYB Transcription Factor, AtMYB44." Int. J. Mol. Sci. 15, no. 5: 8473-8490.