Faculty Profile
Yongjian Qiu
Assistant Professor of Biology
Phone Number: (662)915-3276
Email: yqiu@olemiss.edu
https://phytoresilience.org
Key Words:
Research Description: Research interests in the Qiu Lab are largely directed towards understanding the detailed mechanism by which external and internal signals co-regulate plant growth and development and how to maximize the phenotypic plasticity of plants in the dynamic environmental conditions. In particular, our research focuses on plant morphogenetic responses to light and temperature, two essential environmental factors that regulate almost every facet of plant growth and development. The ultimate goal of our research is to improve functional traits of economic crops in facing global climate change by integrating multidisciplinary knowledge from the Qiu Lab and other scientists.
Global climate change has generated significant fluctuations of ambient growth temperature, which can profoundly influence diverse developmental, physiological, and morphological responses, including modulations in plant growth, flowering, immunity, and yield. Understanding how plants adjust their developmental programs in response to temperature variations is central to sustain crop productivity. Research in my laboratory will use combined genetic, molecular, cellular, biochemical, and genomic approaches to determine how plants sense and respond to changes in ambient temperature.
Daytime temperature is sensed by Phytochrome B through HEMERA
Elevations in ambient temperature are perceived by plants in the dark under short-day (SD) conditions but in the light under long-day (LD) and continuous light conditions, leading to augmented hypocotyl growth at distinct times. However, the molecular mechanisms underlying these differential regulations are not fully understood. Phytochrome B (PHYB), the well-known red/far-red photoreceptor, also functions as an ambient temperature sensor and controls thermosensory hypocotyl growth mainly through PIF4-mediated transcriptional regulation of growth-related genes, particularly those involved in auxin biosynthesis and signaling. My postdoctoral research proposed that PHYB plays distinct roles in thermoresponsive growth under LD and SD conditions. While PHYB mediates nighttime temperature responses in SD conditions by controlling PIF4 transcription through the Evening Complex, we discovered that it controls daytime thermo-induced hypocotyl elongation in LD conditions by regulating the activity and stability of PIF4 through a key PHYB signaling component named HEMERA (HMR).
In my current research, I aim to understand the interplay among PHYB, HMR, and PIF4, three key components of thermomorphogenesis, with the focus on: (1) the modulation of PIF4 stability in response to ambient temperature fluctuation; (2) the transcriptional control of thermo-induced PIF4 target genes; (3) integration of local and systemic signals during thermosensory growth; and (4) interplay between different photoreceptors in thermomorphogenetic responses under natural light conditions.
Honors Theses:
Lott, Julia Nicole (2022) Investigating the Role of Small RNA Pathways in Arabidopsis Shoot Gravitropism (full text)
Newton, Gabriella Rose (2022) The shoot gravitropic response in Arabidopsis requires the Mediator coactivator complex (full text)
Clutton, Caroline (2021) Transcriptional Activation of Phytochrome-Interacting Factor 4 is a Conserved Mechanism of Thermomorphogenesis in Dicotyledenous Plants (full text)
Grant, Chloe (2021) The Importance of a Multidisciplinary Approach to Public Health: Addressing Food Insecurity through a Biological and Sociological Lens (full text)
Available Research Projects:
Investigating molecular mechanisms underlying plant gravitropism
Project Description: Gravitropism in plants is commonly seen in roots (positive gravitropism) and shoots (negative gravitropism). Although some of the mechanisms are shared between these two organs, distinct signaling pathways do exist. The Qiu lab has carried out a series of genetic screens and isolated numerous mutants that are defective in sensing gravity. We are in the process of characterizing these mutants and identify key players in both shoot and root gravitropic responses.
Desired Student Qualifications: 1. Interested in plant science, genetics, and molecular biology research 2. A minimum of a 3-hour block of time at least 3 days a week OR a minimum of a 2-hour block of time at least 4 days a week 3. Communicate well with labmates and the advisor 4. Can work independently
Project Timeline: 09/2021-09/2024
Duties of Student Researcher: 1. Master key lab skills and techniques, including but not limited to plant tissue culture, plant DNA and RNA extraction, PCR and qRT-PCR, DNA and protein gel electrophoresis. 2. Assist graduate students with their daily experiments. 3. Lab chores such as autoclaving tips, tubes, soil, plant waste, and growth media for plants and microorganisms, watering plants, washing labware, and cleaning the lab space. 4. Report work progress to the advisor Dr. Qiu weekly. 5. Summarize research project and write thesis.
Last Updated on 2021-09-23 14:44:08
Investigation of HEMERA-mediated thermomorphogenesis in higher plants
Project Description: The transcriptional co-activator HEMERA (HMR) plays a key role in plant thermomorphogenesis by enhancing the activity and protein stability of PIF4, a key transcription factor that is required for thermo-induced cell growth. The activity of HMR resides in its transcriptional activation domain (TAD), the mutation of which leads to a mutant called hmr-22 that is insensitive to environmental temperature changes. Using genetic screens, we identified multiple suppressors of the hmr-22 mutant. Currently, the Qiu lab is characterizing these hmr-22 suppressors to identify key factors involved in this HMR-mediated thermomorphogenetic pathway.
Desired Student Qualifications: 1. Interested in plant science, genetics, and molecular biology research 2. A minimum of a 3-hour block of time at least 3 days a week OR a minimum of a 2-hour block of time at least 4 days a week 3. Communicate well with labmates and the advisor 4. Can work independently
Project Timeline: 09/2021-09/2024
Duties of Student Researcher: 1. Master key lab skills and techniques, including but not limited to plant tissue culture, plant DNA and RNA extraction, PCR and qRT-PCR, DNA and protein gel electrophoresis. 2. Assist graduate students with their daily experiments. 3. Lab chores such as autoclaving tips, tubes, soil, plant waste, and growth media for plants and microorganisms, watering plants, washing labware, and cleaning the lab space. 4. Report work progress to the advisor Dr. Qiu weekly. 5. Summarize research project and write thesis.
Last Updated on 2021-09-23 14:39:39