The CtrCBL1/CtrCIPK6 Complex of Citrus Phosphorylates CtrBBX32 to Regulate CtrSTP1-Mediated Sugar Accumulation and Cold Tolerance.

ABSTRACT: Sugar accumulation is a crucial adaptive strategy for plant cold tolerance, yet its regulatory mechanisms in the roots under cold conditions remain largely unclear. Here, a cold-inducible sugar transporter protein (CtrSTP1), which is highly expressed in the roots of trifoliate orange (Citrus trifoliata L.), is identified. CtrSTP1 functions positively in cold tolerance by facilitating sugar accumulation in the roots. Two transcription factors, CtrBBX32 and CtrZAT10, bind to the CtrSTP1 promoter, with CtrBBX32 acting as transcriptional repressor and CtrZAT10 as activator. CtrBBX32 also suppresses CtrZAT10 expression. Accordingly, CtrBBX32 and CtrZAT10 act as negative and positive regulators, respectively, of cold tolerance by modulating CtrSTP1 expression. Moreover, CtrCBL1 and CtrCIPK6 form

SUBMITTER: Shang X 

PROVIDER: S-EPMC12697822 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature