SC35-mediated bZIP49 splicing regulates K⁺ channel AKT1 for salt stress adaptation in poplar.

ABSTRACT: Soil salinization threatens plant distribution, crop yields, and ecosystem stability. In response, plants activate potassium (K⁺) signaling to maintain Na⁺/K⁺ balance, though the mechanisms regulating K⁺ uptake under salt stress remain poorly understood. This study identified two splice variants of the bZIP49 transcription factor in Populus tomentosa: unspliced "bZIP49L" and spliced "bZIP49S". bZIP49S, the active form under salt stress, reduces salt tolerance when overexpressed, while bzip49cr knockout enhances it. The serine/arginine-rich splicing factor SC35 was identified as a regulator of bZIP49 mRNA splicing through a self-developed experimental method, and its overexpression enhances salt sensitivity. bZIP49S inhibits the K⁺ transporter AKT1 by binding its promo

SUBMITTER: Liu X 

PROVIDER: S-EPMC12328635 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature