by Emily Caldwell Ohio State News
Study is first to analyze host, pathogen genes in climate change conditions
The high heat and low water conditions produced by global warming weaken pine trees’ resistance to disease by hindering their ability to mount an effective defense at the same time that pathogenic fungi in their tissues become more aggressive, new research suggests.
The study is the first to simultaneously examine metabolic gene expression in both host trees and the pathogens attacking them under normal and climate-change conditions. The findings help explain the mechanisms behind what has become a well-known fact: The warming world makes trees more susceptible to disease.
The study was conducted on Austrian pines, which are native to southern Europe and used ornamentally in the United States. Researchers tested climate change conditions’ effects on the trees after infection by two related fungi that have killed large swaths of these pines over time.
“We decided to study the effects of the combined stresses of higher temperatures and lower water availability because that’s what trees will experience in the future,” said senior author Enrico Bonello, professor of molecular and chemical ecology of trees in The Ohio State University Department of Plant Pathology.
“Within three days of infection under climate-change conditions, the tree was pulled in two different directions: It was deprived of carbon by both reduced photosynthesis and enhanced acquisition of the carbon by the fungi. When we’re talking about carbon, we’re talking about sugars, food and reserves for all other metabolic processes in the trees, including growth and defense.”\Read on:
The research was published recently in the journal Frontiers in Forests and Global Change.
Carbon sequestration by the world’s forests is a major mitigator of climate change’s effects, and could be accelerated if improvements are made to their protection, management and restoration, experts say. In a 2021 study of U.S. forest plots, scientists estimated recent disease and insect disturbances had lowered carbon sequestration rates by 28% and 69%, respectively, from 2001-2019 compared to undisturbed forests.