Have you ever found yourself wondering about the bright colours in flowers, and where those colours come from and why?
Yes, they are important in attracting insects to pollinate them – and attractive to the human eye - but that’s only a tiny part of the story.
New research by Associate Professor Barry Pogson and his team at The Australian National University node of the ARC Centre of Excellence in Plant Energy Biology, based at The University of Western Australia, increases understanding of the links between plant pigments, the regulation of pigment production and a plants’ energy harvesting machinery.
The research features in the August edition of Functional Plant Biology – an internationally respected journal by CSIRO Publishing.
The full research paper can be viewed online at http://www.publish.csiro.au/view/journals/dsp_journal_fulltext.cfm?nid=102&f=FP07034
Associate Professor Pogson said the research had wide-reaching implications for our understanding of atmospheric CO2 levels, climate change, diminishing oil supplies, alternative energy, human nutrition and even eye health.
“Plant energy and plant pigments have major roles to play in all these issues of concern,” he said.
“One of the most important group of plant pigments - the carotenoids – are generally recognised for their contribution to flower and fruit colour, for example carrots and tomatoes.
“They absorb light at the blue end of the spectrum, so light reflected by them appears yellow to orangey/red. In most leafy plant tissue and vegetables, their colour is masked by the green of chlorophyll.
“But they are essential components of the green bits of plants, where photosynthesis traps energy from sunlight and converts CO2 from air to sugars. So carotenoids are essential for photosynthesis and thus life on earth.”
Associate Professor Pogson said natural pigments were an essential part of our diet – our bodies cannot make them so we rely on plants to synthesise them for us.
When we eat plants, our bodies convert some carotenoids into vitamin A. One special carotenoid – lutein and its associate zeaxanthin – have been found in high concentrations in a part of the human eye called the macula. The eye disease, Age-Related Macular Degeneration (AMD), is thought to have its origins in diets deficient in carotenoids.
Associate Professor Pogson said despite this essential role for carotenoids in plant function and human health, the manner in which plants controlled the synthesis of these vital pigments has been far from clear.
“Our research provides two important contributions to our understanding,” he said.
“First, it solves a number of questions about how plants control the amount of carotenoid they make.
“It also shows how the actual photosynthetic energy machinery of plants is assembled, as plants make the change from an etiolated (dark-grown) seedling that lacks photosynthetic capacity to a green photosynthesising tissue.
“Like an orchestra awaiting the arrival of the conductor before the music can begin, it’s as if the components of the photosynthetic machinery can’t come together functionally until lutein arrives and is in place.”
For more information about the work of the ARC Centre of Excellence in Plant Energy Biology, visit www.plantenergy.uwa.edu.au
Associate Professor Barry Pogson 61 2 6125 5629
(ARC Centre of Excellence in Plant Energy Biology) Barry.Pogson@anu.edu.au
Jane O’Dwyer, ANU Media Office 61 2 6125 5001
0416 249 231