Dahlem Centre of Plant Sciences
06.2014. – Present: Dahlem Research School (DRS) Postdoc Fellow, Freie Universität Berlin, Germany (Applied Zoology/ Animal Ecology, Monika Hilker lab)
02.2013. – 05.2014.: Postdoc, University of Neuchâtel, Switzerland (Institute of Biology, Ted Turlings lab)
08. 2006. – 12.2012.: Ph.D., Pennsylvania State University, PA, USA (Dept. of Entomology, Gary Felton lab)
01.2006. – 07.2006.: Korea Science and Engineering Foundation (KOSEF) Postgraduate Fellow, Mokpo National University, Republic of Korea (Dept. of Medicinal Resources, Si-Hyung Park lab)
02.1999. – 01.2005. Research Scientist, National Academy of Agriculture and Sciences, Rural Development Administration, Suwon, Republic of Korea (Dept. of Applied Entomology)
07.1998. – 01.1999. Research Associate, National Academy of Agriculture and Sciences, Rural Development Administration, Suwon, Republic of Korea (Dept. of Biochemistry)
03.1996. – 02.1998. M.Sc., Seoul National University, Suwon, Republic of Korea (Dept. of Agricultural Chemistry, Soo-Un Kim lab)
03.1992. – 02.1996. B.Sc., Seoul National University, Suwon, Republic of Korea (Dept. of Agricultural Chemistry)
Research project during his time as a POINT Fellow
(outline by Dr. Jin-Won Kim)
My research interests lie in the ecological survival ‘strategy games’ played between plants and herbivorous insects: what defenses plants use to fend off challenges from insects and, in return, how insects neutralize host plants' resistance in order to feed on them. More specifically, I am interested in how plants respond to insect eggs from the perspective of defense priming, which is defined as increased readiness of defense induction. After detecting signs of impending herbivory, plants are often primed, leading to stronger or faster induction of antiherbivore defenses upon arrival of the anticipated insect herbivores. Insect eggs that are laid on plants are an unquestionable sign of impending herbivory, and thus the ‘priming of plant defenses by insect oviposition’ makes perfect sense.
However, in the study system of Arabidopsis thaliana and its lepidopteran specialist Pieris brassicae, we have reports both supporting and failing to support the notion of ‘priming by oviposition’. In one report, antiherbivore defense genes of A. thaliana are down-regulated after oviposition and plant hormone analysis suggests suppression of plant defenses. In another report, however, larvae on egg-free plants grow better than egg-treated ones. The latter finding suggests plants' recognition of eggs as impending herbivory and supports defense priming by oviposition. However, the former implies that the butterfly mother manipulates host plant resistance in favor of the offspring, which is likewise ecologically plausible.
Through this DRS fellowship, I seek to pose an answer to this research question. A recent report describes the suppression of plant defenses by insect symbiotic bacteria during the feeding process. I hypothesize that the insect mother releases her symbiotic bacteria with the eggs to suppress plant defenses and that, when the bacterial symbionts are removed, plants will gain back the trait of ‘priming by oviposition.’ In addition, I will define the epigenetic landscape on antiherbivore genes in A. thaliana after egg deposition. Histone modification with ‘active’ or ‘repressive’ marks is the most promising candidate for the molecular mechanism underlying defense priming. I hypothesize that the priming or suppression of plant defenses through insect oviposition is reflected in the abundance of ‘active’ and ‘repressive’ marks on the defense-related genes of A. thaliana.