The TgWRKY24 transcription factor is involved in releasing seed dormancy by responding to abscisic acid signals in Tulipa thianschanica

Tulipa L., a prominent bulbous flower of the Liliaceae family, exhibits profound dormancy traits in its seeds, which significantly constrains its breeding potential. While cold temperature and hormone treatments have been shown to effectively alleviate this dormancy, the underlying molecular mechanisms remain poorly understood. The transcription factor TgWRKY24, a member of the WRKY family, was identified in T. thianschanica seeds, and its functionality was validated. TgWRKY24 subcellularly localizes to the nucleus, and its expression is inhibited by abscisic acid (ABA). The germination of T. thianschanica seeds affected the virus-induced gene silencing (VIGS) system targeting TgWRKY24, resulting in increased ABA content. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays demonstrated the interaction between TgWRKY24 and TgCYP707. TgWRKY24 facilitates seed germination by transcriptionally activating TgCYP707, leading to a reduction in endogenous ABA levels. These findings indicate that TgWRKY24 plays a modulatory role in regulating ABA during seed germination. These findings are important for exploring the molecular mechanism involved in breaking the dormancy of tulip seeds and enriching the germplasm resources of tulips.