[대학원 생명과학과 세미나 안내]
연사 : 정재훈 교수 (성균관대학교 생명과학과)
연제 : Searching for plant thermosensors and future perspectives
일시 : 2019년 5월 17일 (금) 오후 5시
장소 : 하나과학관 A동 B131호
초청교수 : 오은규 교수
Temperature is one of major environmental factor governing the distribution and seasonal behavior of plants. As sessile organisms, plants are highly responsive to small changes in temperature, adjusting their growth and development. The suite of morphological and architectural changes caused by ambient temperatures, between cold- and heat-stress ranges, is called thermomorphogenesis. The outstanding challenge in the research field is to identify the molecules that perceive temperature signals. Over the past decade, numerous molecules have been reported to be involved in plant temperature response, but only one has been identified to function as a thermosensor.
The first thermosensor identified in plants is a red-light photoreceptor phytochrome B (phyB). Phytochrome null plants display a constitutive warm-temperature response, and in this background the warm-temperature transcriptome becomes derepressed at low temperatures. I was found that phytochrome B (phyB) directly associates with the promoters of key target genes in a temperature-dependent manner. The rate of phyB inactivation is proportional to temperature in the dark, enabling phytochromes to function as thermal timers that integrate temperature information over the course of the night.
In addition to phyB, a circadian clock component, EARLY FLOWERING 3 (ELF3) also acts as thermosensory molecule via a prion-related domain (PrD). Surprisingly, ELF3 proteins lacking PrDs make Arabidopsis plants to be unresponsive to warm temperature. It was also observed that ELF3 proteins without the PrD structures do not undergo temperature dependent conformational changes. This study indicates that prion-like protein can play a role as environmental sensors in plants.
In the seminar, I will discuss previous research on the role of phyB and ELF3 as plant thermosensors, and introduce future research to be conducted in Plant Biochemistry Lab (PBL).