Liverworts would rather be 'red than dead'

A Plant & Food Research project into the unique way liverworts shield themselves from extreme environments has been awarded funding for ongoing research in the latest round of Marsden Awards.

Liverworts, simple plants named for some species’ liver-like shape, are closely related to the first plants to evolve on land and tackle the extreme conditions on Earth millions of years ago.  More than 8000 species of liverworts have colonised all parts of the planet, surviving in environments such as the intense cold and light of Antarctica, the rainforests of New Zealand, and the deserts of Australia.

Plant & Food Research lead researcher Dr Kevin Davies says when liverworts are stressed by drought, extreme cold, heat or light, a red pigment called riccionidin increases, altering the structure of cell walls, reducing water loss and cell damage. 

The research project, entitled ‘Better red than dead’, is investigating how and why liverworts build riccionidin into their cell walls.

 “There is the prospect this could help us find ways to improve the tolerance of other plants to more extreme conditions,” he says.

The research team brings together expertise in cell wall biology, plant chemistry, the flavonoid pathway, and marchantia from Plant & Food Research, Lincoln University and Monash University.

Another red flavonoid, anthocyanin, is responsible for red colouration in the flowers, flesh and skins of other plants and their fruit. Anthocyanins also help protect plants, possibly through their anti-oxidative properties. 

“Although the red flavonoids in liverworts and other plants are different, it’s interesting that the mechanism that creates them is similar,” says Dr Davies. 

Dr Davies says liverworts have much more in common with simpler plant ancestors than the flowering plants they split away from around 450 million years ago. “It is possible the cell wall strengthening function we see in liverwort was simply lost as plants evolved in other directions.”

Another project, led by Plant & Food Research scientist and associate professor Dr Richard Macknight, also won Marsden funding to study a mechanism involved in controlling plant genes. 

It follows earlier work on the control of ascorbate in plants, an antioxidant which reduces stress in plants and humans. Kiwifruit are high in ascorbate but other fruit, such as apples, are comparatively low. The research could help select plants high in ascorbate and other desirable characteristics.

Royal Society Te Apārangi selects research projects for government funding on behalf of the Marsden Fund Council. Achieving a Marsden award is considered a sign of research excellence. 

The fund allocated $84.6 million in grants to 133 projects this year, supporting research in science, engineering, maths, social sciences and the humanities.