[대학원 생명과학과 세미나 안내]
연사 : 유희진 박사(Duke University)
연제 : Global translational regulation during plant innate immunity
일시 : 2018년 6월 12일 (화) 오후 4시
장소 : 하나과학관 A동 207호
초청교수 : 백경희 교수
Abstract
Plants have evolved with various defense mechanisms to encounter pathogen infection, which involves transcriptional and translational reprograming. Plants possess two different recognition systems, patter-triggered immunity (PTI) and effector-triggered immunity (ETI). Significant advances have been made in understanding the mechanisms of transcriptional reprogramming in plant immunity, but little is known about translational regulatory mechanisms. Previously, our lab found that translation of a key immune transcription factor TL1-binding factor (TBF1) is rapidly induced without transcriptional change during defense responses, which is the example of translational regulation in one specific gene. To understand genome-wide global translational regulatory mechanisms during immune response, we performed global translatome analysis during PTI using ribosome profiling, which is the deep sequencing of ribosome-protected mRNA fragments. We discovered that translation was tightly regulated and poorly correlated with transcription during PTI. We identified novel immune regulators with altered translational efficiency, and discovered a novel translational regulatory mechanism involving a highly enriched mRNA consensus sequence, R-motif, in the 5'-untranslated region during PTI. Further, we showed that R-motif controls translation in response to R-motif through interaction with poly (A)-binding proteins. To establish how plants control translation in distinct phase of immunity, ETI, we also performed global translatome profiling in response to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326 carrying the effector AvrRpt2. We found that during ETI, translational regulation showed distinct pattern compared to PTI dataset with dynamics on metabolic changes. We further identified novel immune translational regulators in metabolic pathways. Together, our study provides novel molecular mechanism for global translational reprogramming during PTI and a distinct connection to metabolic dynamics via translational regulation during ETI in plants.