Reflecting Photosynthesis: a Tool for Gene Hunters—6 February 2018

A team of plant scientists at the Australian Research Council (ARC) Centre of Excellence for Translational Photosynthesis (CoETP) have developed a methodology that accelerates the discovery of useful genes in wheat, which due to wheat's large genome, is normally a mammoth task that requires hours of painstaking measurements.

“Essentially, we measured the colour of light reflected from leaves, which contains information about many leaf properties, including photosynthesis, the process by which plants transform sunlight and carbon dioxide into sugars,” said lead researcher Dr Viridiana Silva-Perez from CoETP and CSIRO.

“The advantage of this method is that it is non-destructive and quick, allowing the measurement of many plants to map populations and identify useful genes for improving crop production”.

Photosynthesis is a process that depends on many variables, and this measurement gives us a unique fingerprint of each plant’s capacity to capture the sun’s energy,” said ANU Professor John Evans, Chief Investigator at CoETP.

“This technique allows scientists the see how big the engine inside plant cells is. It permits us to ask very useful questions about what is happening inside the plant, for example, if the plant can get more carbon for the water it spends.”

It takes researchers 20 minutes per leaf to obtain part of this information using traditional methods. Now, this methodology enables 100 measurements per hour.

“In the time it takes you to take one measurement with other methods, hyperspectral reflectance allows you to predict a whole suite of leaf properties. These include the dry mass of the leaf per unit area, nitrogen and chlorophyll contents, quantity of the enzyme Rubisco and electron transport capacities. More leaf properties are being added,” says Professor Evans.

During the study, the scientists worked in wheat fields in Australia and Mexico, and compared hyperspectral reflectance to other methods, which allowed them to calibrate the technique. Since then, the technique has been used for other crops such as corn, rice and sorghum in Australia, the UK and the USA.

The research has been published in the Journal of Experimental Biology.

Media issued by CoETP.


Image: Lead researcher Dr Viridiana Silva Perez in the field.
Credit: Charles Tambiah.


Original Published Date: 
Tuesday, February 6, 2018