Download PhD in C4 Photosynthesis Research: Carbon Assimilation

PhD in C4 Photosynthesis Research: Carbon
Assimilation
Research area
Photosynthesis is the process by which plants, algae and some bacteria convert carbon
dioxide and water into carbohydrates using energy from sunlight. Photosynthesis consists of
a complex series of reactions comprising four key stages: light absorption, charge separation,
carbon fixation and oxygen evolution. A plant’s efficiency at turning CO2, water and light into
biomass is extremely low, typically around 4-5% at best. Where do these limitations come
from and can they be overcome to produce crops with higher yields?
Some plants (known as C4) have partially solved this problem by developing mechanisms to
concentrate CO2 in leaves. Sorghum (Sorghum bicolor), an African grass related to sugar cane
and maize, is grown globally for food, feed, fibre and fuel. Of particular importance to
sorghum productivity is C4 photosynthesis, comprising biochemical and morphological
specializations that increase net carbon assimilation at high temperatures.
Sorghum is the dietary staple of more than 500 million people in over 30 countries, making it
the world’s fifth most important crop for human consumption after rice, wheat, maize and
potatoes. Working in sorghum provides a unique opportunity to link up-stream science to the
challenge of global food security. In fact, members of this broader research team are already
working with scientists in sub-Saharan Africa and central-western India to improve crop yields
under dry conditions.
Through this PhD project we seek to identify genetic variation in traits affecting stomatal
conductance, and hence photosynthesis, in C4 plants, using sorghum as a model. Genetic
variation in light interception, stomatal conductance, photosynthetic capacity and efficiency
exists in a range of major C3 and C4 cereal crops. However, to date, these traits have not been
directly targeted for improvement by plant breeders, predominantly due to the difficulty and
expense of measuring these traits on large numbers of individuals and the lack of validated
targets confirmed to improve crop yield. One approach to capture this genetic variation would
be to mine the natural and induced variation to discover genes and mechanisms controlling
photosynthetic performance – in this case focusing on carbon assimilation in C4 plants.
Organisational Environment
This PhD position will be based primarily at the Hermitage Research Facility, located 150 km
south-west of Brisbane. The successful candidate will work with a multi-disciplinary team of
scientists (crop physiology, quantitative genetics, genomics, plant breeding, molecular
biology, simulation modelling, bioinformatics) from the University of Queensland and the
Australian National University, as part of the Centre of Excellence for Translational
Photosynthesis, a unique and world-class research collaboration funded by the Australian
Research Council. The PhD student will interact closely with other students and staff located
at the Queensland Alliance for Agriculture & Food Innovation (QAAFI) at the University of
Queensland’s main campus in St Lucia, Brisbane.
Hermitage Research Facility, Warwick
The Queensland Government’s Hermitage Research Facility is Queensland’s oldest scientific
research institute. Hermitage is a centre of excellence for crop improvement in water-limited
environments, with about 50 staff undertaking multi-disciplinary research in summer cereals
(sorghum and maize), winter cereals (barley and wheat), and pulses (mungbeans and
chickpeas).