biological sciences HONOURs 2014 - The University of Sydney

16 PHOTOSYNTHESIS IN
MARINE CYANOBACTERIA
Research Interests
Light is both an energy source and a deliverer of environmental
information. There are two kinds of photopigment-binding
protein complexes in photosynthetic organisms: one to absorb
and convert sunlight as the energy source, and another
to sense sunlight as an environmental information carrier.
Different photosynthetic pigments allow the organism to use
a wider spectral region of sunlight. My research centres on
understanding the red-shifted chlorophylls, their function in
photosynthesis and the regulatory mechanisms. The major
questions are: How do these cyanobacteria produce red-shifted
chlorophylls? What kind of photoregulatory mechanisms do
these cyanobacteria use to sense light conditions?
Honours projects
1. The pigmentation in photosynthetic organisms. This project
will investigate the structural details of light-harvesting protein
complexes in H. hongdechloris, a newly isolated chlorophyll
f-containing cyanobacterium. There are two distinct lightharvesting
systems, chlorophyll-bound protein complexes and
phycobilin-bound protein in H. hongdechloris. The intriguing
question is how the energy transfer occurs between pigmentbinding
protein complexes and whether is there an “uphill”
Associate Professor
Min Chen
Room 219B, Heydon-
Laurence Building A08
T: (02) 9036 5006
E: min.chen@sydney.
edu.au
energy transferring mechanisms. The project would best suit candidates with knowledge of
plant physiology, general conception of photosynthesis and plant bioenergy. The experiments will
involve techniques such as spectrophotometry and pigment analysis and protein biochemistry.
2. Red-light perception and its regulatory roles. The process of sensing and responding to
light, broadly termed “photoregulation”, affects a diversity of metabolic processes. The most
important photoreceptor is phytochrome, a red-light-sensing photoreceptor. There are two
photo-interconvertible phytochrome isoforms: a red light-absorbing form and a far-red lightabsorbing
form. This project will explore the regulatory functions of phytochrome and the
meaning of far-red light (invisible light) for oxygenic photosynthesis by searching the classes of
red-light receptors and their regulatory roles related to red-shifted chlorophylls (Chl d and Chl f).
The project would best suit candidates with knowledge of plant physiology, general conception
of photosynthesis and biochemistry of photopigments. The experiments will involve techniques
of spectrophotometer and photoconvertion analysis in vivo and in vitro. Standard molecular
biological technology (PCR, cloning, etc) will be applied to the understanding of the structural
basis of signal transduction in red-light perception.