Characterization of the CBL-CIPK network and its association with ABA signaling in the drought response of Asparagus cochinchinensis
摘要
Asparagus cochinchinensis (Lour.) Merr. (A. cochinchinensis) is a precious traditional Chinese medicinal herb with significant economic value. However, its cultivation is severely constrained by environmental stresses, particularly drought. The Calcineurin B-Like (CBL) and CBL-Interacting Protein Kinase (CIPK) network constitutes a crucial calcium sensor system that decodes stress-induced Ca2+ signatures in plants. Despite its importance, the molecular architecture and functional roles of the CBL-CIPK network in A. cochinchinensis remain largely uncharacterized.
ResultsIn this study, we generated a high-quality full-length transcriptome of A. cochinchinensis using PacBio Single-Molecule Real-Time (SMRT) sequencing, yielding 52,042 non-redundant transcripts. Based on this resource, we identified 35 AcCIPK and 13 AcCBL genes. Phylogenetic analysis revealed high conservation between AcCIPK24/AcCIPK23 and their Arabidopsis orthologs, while also uncovering species-specific alternative splicing events, including a truncated isoform of AcCIPK24.5. Yeast two-hybrid assays confirmed a specific physical interaction between AcCBL10 and AcCIPK24. Expression profiling demonstrated that these genes exhibit tissue-specific and temporal responses to drought stress. Notably, while both genes were downregulated in roots and stems under drought, AcCBL10 was significantly upregulated in cladodes, suggesting complex regulatory mechanisms. Furthermore, hormone analysis revealed that drought stress induced endogenous ABA accumulation, and exogenous ABA application not only accelerated the endogenous ABA accumulation peak but also enhanced the expression of AcCBL10 and AcCIPK24.5, suggesting a certain connection between calcium signaling and ABA pathways.
ConclusionThis study provides the first comprehensive functional characterization of the CBL-CIPK network in A. cochinchinensis. The specific interaction between AcCBL10 and AcCIPK24, coupled with the crosstalk between calcium signaling and ABA pathways, suggests a potential molecular framework underlying drought adaptation in this medicinal plant.
Graphical abstract