ABA-Insensitive 5 (ABI5) Is Involved in ABA-Induced Dormancy via Activating Expression in Sweet Cherries.

BACKGROUND/OBJECTIVES: In perennial plants, developing floral buds survive winter through entering a dormant state, which is induced by low temperature and abscisic acid (ABA). ABA performs vital functions in the dormancy process. ABA-insensitive 5 (ABI5) transcription factor is a key regulator in the ABA signaling pathway. However, little is known about the regulation of ABI5 in the winter dormancy of sweet cherries.

METHODS

We identified the sweet cherry gene and its expression changes using gene cloning and qRT-PCR. Additionally, we validated the interaction between PavABI5 and PavCIG1/2 using Yeast One-Hybrid and Dual-Luciferase Assays.

RESULTS

In this study, we identified a basic leucine zipper (bZIP) family gene from the sweet cherry, which was closely related to from , from , from , and from , through phylogenetic tree analysis. The seasonal expression pattern showed that the PavABI5 level was increased during the winter dormancy stage and induced by exogenous ABA. Specifically, we found that the expression of cherry cold-induced genes () was positively correlated with expression. Furthermore, PavABI5 directly bound to the ABRE elements in the promoters to activate their expression. We further confirmed that the dormancy-associated MADS-box () genes and function downstream of the ABA signaling pathway to regulate bud dormancy in sweet cherries.

CONCLUSIONS

Our findings suggest a putative regulatory model of ABA-mediated bud-dormancy with .