Australian researchers have discovered that a common grass species called Panic Grass (Panicum spp.) contains enzymes that capture CO2 from the atmosphere more efficiently than other plants in the extreme climate conditions predicted in coming decades.
Recently published in Nature Plants, this discovery is a significant progress in the quest to use the natural genetic diversity of grasses to increase crop yields and respond to farmers and scientists’ concerns about the plateau in global crop productivity gains over recent decades.
“We are focusing on Rubisco, the enzyme that captures CO2 from the air to begin the production of sugars that plants need to grow for biomass and seed which in turn animals and people consume as food. We are aiming to enhance the functioning of this crucial enzyme by finding more efficient versions in other grasses and plant species that might benefit crop growth and yield,” said ANU lead researcher Dr Robert Sharwood.
Joint researchers at the Australian National University’s Research School of Biology and Western Sydney University’s Hawkesbury Institute for the Environment are studying how to enhance the ability of crops such as wheat and rice to fix CO2 from the air more effectively to increase their growth and yield. As members of the ARC Centre of Excellence for Translational Photosynthesis, their goal is to increase the yields of staple cereals and to ready them for a world of increasing temperature extremes and a population of nearly ten billion people by 2050.
There are two main ways in which plants convert sunlight and CO2 into food and oxygen, called C3 and C4. One of the crucial differences between these two pathways is that their Rubisco enzymes have quite contrasting CO2 –fixing capabilities that differ in their response to temperature.
“We were very excited to discover considerable variability in the capacity of Rubisco from different C3 and C4 Panicum grasses to convert CO2 into carbohydrates under a wide range of temperatures” explains Associate Professor Oula Ghannoum from Western Sydney University. “Using mathematical simulations of the data, we identified Rubisco enzymes that are best-suited to crops growing under both hotter and cooler temperature conditions,” she said.
“Successfully transplanting the efficiencies of these grass Rubiscos into staple food crops such as wheat and rice would bring us one step closer to being able to produce higher-yielding varieties capable to cope with the more variable climates and higher CO2 atmosphere of the future”, explains Associate Professor Spencer Whitney from the Australian National University.
“With very little new land available for agriculture, the need to do more with the farming land we have is becoming dire. On top of this are the changes in climate coming our way in the next few decades and the growing demand for food. That is our goal within the ARC Centre of Excellence in Translational Photosynthesis – to discover aspects of the world’s plant diversity that can be used to the advantages of our food crops”, explains Dr Sharwood.