23 November 2017
An ancient anti-fungal defense
Published online 26 September 2016
A bacterial microbe that lives within one of Africa’s ancient staple crops reveals a protective streak.
Fusarium graminearum is a fungus that causes devastating losses in crops such as maize and wheat; yet their relative, finger millet, is widely resistant to it.
A team of researchers from Egypt, Canada, and the US discovered that M6, a bacterial organism that lives in the roots of finger millet, can fend off the fungus1.
M6 can sense the presence of Fusarium in the soil. It moves in a way similar to human immune cells to trap the fungus then produces natural fungicides to kill it.
The team found that M6’s anti-Fusarium activity can be transferred to maize and wheat by coating their seeds with it prior to sowing.
“This microbe helps to point to the future; where farmers will harness the power of microbes that naturally live within plants as probiotics to reduce their need to purchase pesticides and fertilizers every year,” says Manish Raizada, associate professor of agriculture at Canada’s University of Guelph.
Finger millet was domesticated in East Africa around 5,000 BCE, and there is evidence that Fusarium also evolved in Africa. The study, together with previous work, suggests that finger millet, Fusarium, and M6 co-evolved, giving this crop a protective advantage not present in crops related to it that were domesticated elsewhere in the world.
Finger millet is understudied, despite its huge significance for tens of millions of people around the world “because it is not grown or consumed in Western nations,” explains Raizada.
“It is hoped that the exciting results of this research will encourage other scientists to explore ancient, neglected crops for beneficial microbes and their potential real-life applications,” adds Walaa Mousa of Egypt’s Mansoura University and the University of Guelph.
- Mousa, W. K. et al. Root-hair endophyte stacking in finger millet creates a physicochemical barrier to trap the fungal pathogen Fusarium graminearum. Nat. Microbiol. http://dx.doi.org/10.1038/nmicrobiol.2016.167 (2016).