The ash dieback fungus is a major threat to ash trees in the UK and Europe. The disease is caused by a fungus that attacks the leaves and stems of ash trees, causing them to wilt and die. Ash dieback has already killed millions of ash trees in the UK and is expected to kill even more in the future.

Scientists are working on a number of ways to combat ash dieback, including developing resistant ash trees. One promising approach is to use disease tolerance genes. Disease tolerance genes allow plants to tolerate the presence of a pathogen and to continue to grow and reproduce even when infected.

Several disease tolerance genes have been identified in ash trees, and these genes are being used to develop resistant ash trees. These trees are showing promise in field trials, and they could eventually be used to replant ash trees in areas that have been affected by ash dieback.

The development of disease tolerance genes is a major breakthrough in the fight against ash dieback. These genes could help to save the ash tree from extinction and to restore its vital role in the UK and European ecosystems.

Here are some of the benefits of disease tolerance genes:

* They allow plants to tolerate the presence of a pathogen and to continue to grow and reproduce even when infected.

* They can help to slow down the spread of disease.

* They can help to reduce the severity of disease symptoms.

* They can help to improve the overall health and vigor of plants.

Disease tolerance genes are a promising new tool for fighting plant diseases. They could help to protect crops from disease and to reduce the need for pesticides.