Recently, Dr. Li Pu’s group from Biotechnology Research Institute and Dr. Jiaqiang Sun fromInstitute of Crop Sciences of Chinese Academy of Agricultural Sciences, revealed a novel epigenetic mechanism underlying the regulation of organ size in plants. The work, entitled “The trxG protein ULT1 regulates Arabidopsis organ size by interacting with TCP14/15 to antagonize the LIM-peptidase DA1 for H3K4 trimethylation on target genes”, was published in Plant Communications on Jan. 12 2024.
Plant organ size is an important agronomic trait that greatly determines plant yield. However, despite its central importance, the genetic and molecular mechanisms underlying organ size control remain elusive. In this study, the authors report the trithorax group protein ULTRAPETALA1 (ULT1) interacts with TCP14/15 transcription factors (TFs) by antagonizing the LIM-peptidase DA1 to regulate organ size in Arabidopsis. Loss of ULT1 function significantly increases rosette leaf, petal, silique and seed size, while overexpression of ULT1 results in reduced organ size. ULT1 associates with TCP14 and TCP15 to co-regulate cell size by affecting cellular endoreduplication. Transcriptome analysis reveals that ULT1 and TCP14/15 regulate common target genes involved in endoreduplication and leaf development. ULT1 can be recruited by TCP14/15 to promote H3K4 trimethylation (H3K4me3) at target genes, thereby activating their expression to determine final cell sizes. Furthermore, they found that ULT1 influences the interaction of DA1 and TCP14/15 and antagonizes the effect of DA1’s degradation on TCP14/TCP15. These findings provide significant insights into the epigenetic regulatory mechanisms linking the regulation of cell and organ size with endoreduplication in Arabidopsis.
Dr. Fan Xu and Dr. Huixue Dong (Institute of Crop Sciences of Chinese Academy of Agricultural Sciences) contributed equally to this work. This work was supported by the National Natural Science Foundation of China (31872805), the Fundamental Research Funds for Central Non-Profit of Chinese Academy of Agricultural Sciences (CAAS-ZDRW202109 and Y2023PT20) and the Nanfan special project of Chinese Academy of Agricultural Sciences (YBXM15).
More details can be found at the link:https://doi.org/10.1016/j.xplc.2024.100819
Figure. Epigenetic modules of ULT/DA1-TCP14/TCP15-H3K4me3 controlling organsize in plants |