Understanding how a fungal pathogen interacts with rice cells could help us engineer new defences
Rice is one of the world’s most important agricultural crops, with 741.5 million tonnes produced in 2014. A large proportion of the global population relies on rice as a staple food, particularly in Asia and Africa. However, harvests are threatened by rice blast disease, caused by the fungus Magnaporthe oryzae, which destroys enough rice to feed around 200 million people every year. Rice and the rice blast fungus are involved in a co-evolutionary arms race, fighting for the upper hand. As the fungus relies on effector proteins to help it infect and reproduce within rice plants, rice has evolved immune receptors that allow it to detect and prevent the spread of the fungus. However, the rice blast fungus has evolved stealthy effector proteins that remain undetected by the rice immune system but can still promote disease. In work recently published in the Journal of Biological Chemistry, an international team of scientists has investigated how one stealthy effector protein might maintain its disease-promoting activity but evade immune detection. This research has an ultimate aim of engineering a receptor that would allow rice plants to better defend themselves.
A pain in the paddy field
We’re familiar with images of the rice paddies of Asia, but this impressive sight represents an irresistible target for the rice blast fungus, Magnaporthe oryzae. Unable to run away from pests and pathogens, plants have evolved immune systems to detect and defend against attack. However, huge swathes planted with the same variety creates an evolutionary pressure for pests and pathogens; a feast is at hand if they can evade those defences.
One way that pathogens try and gain an advantage is through the use of effector proteins. These proteins can suppress the plant’s immune system and manipulate the plant’s own systems to help the pathogen infect and replicate. However, the mechanisms they employ to do so are not fully understood.
In collaboration with scientists from Japan and Thailand, researchers at the UK’s John Innes Centre and The Sainsbury Laboratory have been investigating the interaction between rice plants and the rice blast fungus, with the ultimate goal of engineering new genetic resources that will help rice fight this damaging disease.
Read more on the Diamond website
Image: Rice fields in Asia