Visiting Speaker Seminar: Dr Peter Gollan
Nov 19, 10:30 am
Photosynthetic redox homeostasis triggers chloroplast signalling and influences plant metabolism
Presented by Dr Peter Gollan, Molecular Plant Biology, Department of Biochemistry | University of Turku, Finland
When: 10.30 am, Tuesday, 19 November.
Where: Plant Research Centre Auditorium, Hartley Grove, Waite Campus.
Photosynthetic light reactions operate as both sensor and transmitter, perceiving and communicating information about the plant’s environment. Changes in environmental conditions can disturb the homeostasis within the photosynthetic energy/electron transport system, leading to the formation of various signalling compounds in the chloroplast, especially reactive oxygen species and oxidised metabolites, which ultimately reprogram the expression of nuclear genes. We have used combinations of gene mutants and specific light treatments to study the effects of altered photosynthetic redox balance on chloroplast signalling and primary metabolism in Arabidopsis. We found that increased excitation/reduction pressure on photosystem II (PSII) upregulates signalling through lipid metabolites (oxylipins). This signalling activity promotes secondary metabolism and is especially active during recovery from stress. Inactivation of photosystem I (PSI) triggered oxylipin signalling especially under low light conditions, but also impaired normal abiotic stress signalling in high light. At the same time, inhibition of PSI had a protracted negative effect on carbon assimilation and primary metabolism. Our results show that discreet signals derived from either PSI or PSII are integral for perceiving environmental fluctuations through photosynthetic redox homeostasis.
About the speaker:
Originally from rural Victoria, Peter Gollan completed his undergraduate and doctoral studies at Swinburne University of Technology, Melbourne. His GRDC-funded PhD project analysed molecular chaperones involved with photosynthesis in wheat. After obtaining his PhD in 2011, Peter began a postdoc in the lab of Professor Eva-Mari Aro at the University of Turku, Finland. He held an Academy of Finland postdoctoral fellowship from 2014 – 2017. Peter is currently a senior researcher in the Aro group working primarily on the impacts of photosynthesis on chloroplast signalling and metabolism.