Genetic mechanism of wheat disease identified

A genetic mechanism that could stop the spread of a ‘devastating’ disease threatening wheat crops has been identified by scientists working at Durham University, working with partners from Newcastle University and Rothamsted Research.

Septoria leaf blotch (STB) is caused by a fungus and is seen as the most significant threat to wheat yields in Europe, and most other wheat growing regions, as currently available fungicides become less effective against resistant strains of the disease.

A key feature of STB is the long symptomless growth of the fungus – Zymoseptoria tritici – which can affect the host plant’s cells before it switches to the visible disease phase that eventually destroys the plant’s leaves.

The team found that a wheat protein, TaR1, was key in enabling Zymoseptoria tritici to maintain this symptomless growth.

By manipulating TaR1 protein levels in wheat, the researchers demonstrated that they could activate the plant’s defences earlier.

Lead author Dr Ari Sadanandom, in the Durham Centre for Crop Improvement Technology, Durham University, said: “The foundation of global food security is built on three cereals, wheat, rice and maize, and wheat is the leading source of vegetable protein in human food.

“STB drastically affects yield by destroying the leaves on wheat plants, reducing their capacity to carry out the photosynthesis needed for grain production. It’s a significant threat as the fungicides that are currently the only control for this disease become less effective.

“However our findings show that by manipulating the TaR1 protein we can create unfavourable conditions preventing the spread of STB in the plant, potentially providing a new strategy for combatting this devastating disease,” she concluded.

The research has been published in the journal New Phytologist.