BrrTCP4b interacts with BrrTTG1 to suppress the development of trichomes in Brassica rapa var. rapa .

The number of trichomes significantly increased in CRISPR/Cas9- edited BrrTCP4b turnip ( Brassica rapa var. rapa ) plants. However, the underlying molecular mechanism remains to be uncovered. In this study, we performed the Y2H screen using BrrTCP4b as the bait, which unveiled an interaction between BrrTCP4b and BrrTTG1, a pivotal WD40-repeat protein transcription factor in the MYB-bHLH-WD40 (MBW) complex. This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation. Furthermore, it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex, resulting in decreased expression of BrrGL2 , a positive regulator of trichomes development. In contrast, AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana . Overall, this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip, indicating a divergence from the mechanisms observed in model plant A. thaliana . The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(© 2024 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.)