Scientists unlock the molecular defense of Alpine trees

Researchers have found a way to tackle a disease that threatens thousands of acres of Alpine forest each year.

Rust of bladder leaves causes the spruce of Norway to turn yellow and fall out, causing a significant reduction in growth.

Scientists in Austria have uncovered a natural defense mechanism that the species can use to protect the potentially fatal pathogen.

The findings were published in the journal BMC Genomics.

Disease is one of the major threats facing trees around the world, especially in a warming world where many organisms find themselves in an environment in which they are under increasing levels of stress.

It is widely predicted that invasion pathogens, and the insects that can spread them, are expected to thrive in a world experiencing climate change.

In evolutionary terms, harmful pathogens evolved in addition to plants trying to protect themselves, creating a cold war of several millennia between biological kingdoms.

It is a natural defense mechanism that a team of scientists used to create a system to protect the Norwegian spruce from needle bladder rust.

• Genetics can play an important role in tree storage

Tree selection

“Our research seeks to curb this disease and discover the molecular defense mechanism of Norwegian spruce against infection from emergency injury,” explained co-author Carlos Trujillo Moya, a researcher at the Austrian Forest Research Center.

Dr Trujillo Moya and colleagues have continued to monitor Norway’s spruce trees in the mountains of Austria, allowing the team to select trees that appear to show resistance to the disease.

From these trees, the team was able to generate clones and then study the genes, as well as study the production of chemical compounds of defense.

Dr Trujillo Moya told BBC News that trees that showed resistance to the rust of the needle bladder defended themselves through a “hypersensitive reaction”.

“This defense mechanism consists in the production of a complex artillery of proteins and chemical compounds that isolate the fungus in the attacking leaves,” he explained.

“The infected part of the leaf dies in a controlled manner and thus prevents the fungus from spreading through the rest of the tree.

“This reaction occurs two to three weeks after the infection and lasts at least one month.”

The team said the findings represented “enormous progress” in the way Norway’s spruce trees are selected because of their resistance to the pathogen rust pathogen (Chrysomyxa rhododendron).

“Our findings allow us to better identify resistant clones and promote the establishment of replanting programs using selected trees, based on most effective hypersensitive defense reporting,” observed Dr. Trujillo Moya.

He concluded by saying that this research helps address one of the key issues for the ecological and economic sustainability of Alpine ecosystems.