DIGIST New Biology

교수

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임평옥

교수, 전공책임교수

Biography

Pyung Ok Lim received her Ph.D. in Genetics program from Michigan State University and trained as a postdoctoral fellow at University of California, Los Angeles (UCLA) and POSTECH. Afterwards, she had been a faculty member at Jeju National University. She moved to DGIST in 2012 and has been as a chair of New Biology department since 2013.
Degree Michign State University, PhD.
Office E4-615
Tel +82-53-785-1830
E-mail polim@dgist.ac.kr
Lab 식물노화연구실

Overview

How plants know when and how to die?


Leaves undergo developmental and physiological changes during their lifespan, ending with senescence and death. Leaf senescence is an important developmental phase and considerably impacts crop yields. During senescence, leaves change their role from nutrient-accumulating organs through carbon fixation and nutrient uptake to nutrient-exporting organs, resulting in nutrient recycling to developing organs.

 

Leaf senescence is a part of the plant developmental process but can be triggered by environmental changes that are integrated into the developmental aging program. This integrated senescence response determines the pattern of leaf senescence and contributes to improved survival in a given ecological niche.

 

The focus of the research is aimed at increasing our knowledge of leaf senescence at the molecular and biochemical levels. The elucidation of their mechanisms of regulation will present an insight into the complex processes that control this key developmental process and allow future manipulation of senescence for agronomic benefit.

 

 

 

 

Research Summary

A.Systems Biology of Arabidopsis leaf senescence

 

Our overall goal is to gain insights into system-level understanding of leaf senescence at molecular, cellular, intercellular levels. To investigate age-dependent changes in multiple transcriptomes over the leaf lifespan, we performed directional total RNA-seq and small RNA-seq analysis of Arabidopsis leaves collected at 14 and 7 time points, respectively, encompassing the entire lifespan. These data provide a set of interesting and important hypotheses.

 

Multi-dimensional leaf lifespan transcriptome carta of Arabidopsis926414ce87ecf3198168fffe477541e7_1565334

 

 


B. Temporal dynamics of RNA-RNA, RNA-Protein, RNA-DNA networks along leaf life history and senescence

 

 

- Studying the long noncoding RNAs-mediated regulatory mechanisms using various functional analyses

- Understanding the importance of regulatory IncRNAs on plant fitness.

- Understanding molecular basis of RNA-DNA-protein interaction in leaf development.​​

 

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C. Spatiotemporal design of the hierarchical biological clocks in Arabidopsis

 

- Study on Spatiotemporal transition of biological clock along leaf development

- Identification of genetic machineries maintaining the coordination and designing spatiotemporal transition of biological clock​​

- Predication of leaf cell fate by monitoring cellular clock 

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D. Computational Study of Leaf Senescence through a Phenomic Approach

 

Leaf senescence is influenced by its life history, comprising a series of developmental and physiological experiences. Exploration of the biological principles underlying leaf lifespan and senescence requires a schema to trace leaf phenotypes, based on the interaction of genetic and environmental factors. We developed a new approach and concept that will facilitate systemic biological understanding of leaf lifespan and senescence, utilizing the phenome high-throughput investigator (PHI) with a single-leaf-basis phenotyping platform. Our pilot tests showed empirical evidence for the feasibility of PHI for quantitative measurement of leaf senescence responses and improved performance in order to dissect the progression of senescence triggered by different senescence-inducing factors as well as genetic mutations. Such an establishment enables new perspectives to be proposed, which will be challenged for enhancing our fundamental understanding on the complex process of leaf senescence. We further envision that integration of phenomic data with other multi-omics data obtained from transcriptomic, proteomic, and metabolic studies will enable us to address the underlying principles of senescence, passing through different layers of information from molecule to organism.

         

- Investigation of association among phenomic responses, lifespan, and various environmental cues in various accessions through PHI  

  (Plant High-throughput Investigator) system

Dissection of molecular networks in accessions with distinct lifespan history​​​​

 

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Selected Publications

 

  Woo HR, Kim HJ, Lim PO*, Nam HG* (2019) Leaf senescence: Systems and dynamics Aspects Annual review of plant biology *Co-corresponding author

 

Lyu JI, kim JH, Chu H, Taylor MA, Jung S, Baek SH, Woo HR, Lim PO*, Kim J* (2019) Natural allelic variation of GVS1 confers diversity in the regulation of leaf senescence in Arabidopsis. New Phytologist 221:2320-2334 *Co-corresponding author

 

Kim HJ, Park JH, Kim JK, Kim JJ, Hong SH, Kim J, Kim J, Woo HR, Hyeon C, Lim PO*, Hwang D*, and Nam HG* (2018) A NAC troika directs aging by regulatory inversion of age-evolving. Proc Natl Acad Sci U S A 115: E4930–4939. *Co-corresponding author

 

Km J., Park SJ, Lee IH, Chu H , Penfold CA, Kim JH , Buchanan-Wollaston, Nam HG, Woo HR, and Lim PO (2018) Comparative transcriptome analysis in Arabidopsis ein2/ore3 and ahk3/ore12 mutants during dark-induced leaf senescence, J Exp Bot. 69:3023-3036

 

Lee SY, Jeong HB, Lee SC, Lee JW, Kim SJ, Park JW, Woo HR, Lim PO, An GH, Nam HG and Hwang DH (2017) Molecular bases for differential aging programs between flag and second leaves during grain-filling in rice, Scientific Reports, 7:8792

 

Lyu JI, Baek SH, Jung S, Chu H, Nam HG, Kim J, and Lim PO (2017) High-throughput and computational study of leaf senescence through a phenomic approach, Frontiers in Plant Science, 8:250

 

Woo HR, Koo HJ, Kim J, Yang JO, Lee IW, Jun J, Choi SH, Park SJ, Kang B, Kim YW, Phee BK, Kim JH, Seo C, Park C, Kim SC, Park S, Lee B, Lee S, Hwang D, Nam HG and Lim PO (2016) Programming of plant leaf senescence with temporal and inter-organellar coordination of transcriptome in Arabidopsis, Plant Physiology, 171:452-467.