Title: The intronic silencing element SE1 epigenetically suppresses Eui1 via a repressor complex
Speaker: Prof. Letian Chen, South China Agricultural University
Day/Date: Thursday/May 10th, 2018
Host PI: Prof. Yoji Kawano
Venue: PSC Auditorium
Plant hormone gibberellic acid (GA) regulates many developmental processes that feed into plant height. Rice ELONGATED UPPERMOST INTERNODE 1 (Eui1) encodes a GA-deactivating enzyme governing elongation of uppermost internode. Here, we identified a dominant dwarf mutant, dEui1, caused by the deletion of an RY motif-containing cis silencing element (SE1) in the intron of Eui1. Detailed genetic and molecular analysis of SE1 revealed that this intronic cis-element recruits at least a trans-acting repressor complex, containing the B3 repressors OsVAL2 and OsGD1, the SAP18 co-repressor, and a histone deacetylase OsHDA710. This complex generates closed chromatin at Eui1, suppressing Eui1 expression and modulating GA homeostasis. Loss of SE1 or dysfunction of the complex components impairs histone deacetylation and H3K27me3 of Eui1 chromatin, thereby increasing Eui1 transcription, and decreasing bioactive GA; producing dwarfism in rice. Together, our results reveal a novel model in which the intronic cis element SE1 negatively regulates Eui1 expression via repressor complexes that modulates histone deacetylation and/or methylation.
The seminar will be delivered in English.