Study could help plants withstand drought

Pramuditha Waidyarathne, who recently completed her thesis, says this knowledge can help us improve plants’ capacity to withstand the effects of severe climatic conditions.

“One of the biggest global problems is freshwater scarcity. Plants account for 65 per cent of global freshwater use,” says Waidyarathne.

“When drought occurs, plants quickly adapt at a cellular level. Understanding these mechanisms is crucial for us to enhance plants’ ability to protect themselves during a drought.”

Professor Sandhya Samarasinghe, of Lincoln University’s Department of Informatics and Enabling Technologies, supervised Waidyarathne’s project.

Samarasinghe says the thesis has lifted scientists’ understanding of plant drought response to a new level.

When a plant is under stress, the small pores on the surfaces of its leaves close, allowing it to retain water. This gives the plant a much better chance of surviving drought conditions.

A factor playing a large role in the closure of the pores is a hormone called phytohormone abscisic acid (ABA), which plants produce to regulate growth, development and stress responses.

ABA triggers the closure of the pores.

However, information about how a plant’s related cell-signalling networks communicate during this process is not yet properly understood, says Waidyarathne.

Her study made the first attempt at computer modelling the ABA signalling network from a holistic perspective, by looking at all data and evidence already available in existing literature on the subject.

“ABA signalling involves a large number of proteins and other molecules that are interconnected to form a complex network,” she says.

“My study uses computer modelling to develop an easy-to-digest system that shows how the protein-signalling pathway leads to rapid pore closure in plants. This has generated new insights into how these proteins are connected and why.”

Waidyarathne says the last attempt at computer modelling ABA signalling was reported in 2006, but it lacked current knowledge, depth and a holistic perspective.

“Since then, the discovery of the ABA receptor complex highlighted a new era for this research, but a systems biology approach has not yet been made to discover how these findings affect our current view of the signalling.

“My study was an advanced systems biology approach that revealed a number of novel insights into the functioning of the ABA signalling network, and provides a clearer picture of the process.    

“The model can be used to find ways to improve plant drought stress response, which is crucial in the face of prevailing climate change.”