In the UK, thousands of oak trees are “bleeding,” oozing dark liquid from cracks on their bark. What lies underneath are fluid-filled necrotic cavities that disrupts their life force by impeding the normal flow of nutrients and water. Taking advantage of the weakened state of the trees, are bark-boring beetles, which lay their eggs in the cracks of the bark. These are the characteristic signs of Acute Oak Decline, a disease that can kill a tree within four or five years of symptom onset.
Acute Oak Decline made its appearance in 2008. Now, scientists have found that Acute Oak Decline is caused by a polymicrobial infection – in this case, a simultaneous infection of three bacterial species: Brenneria goodwinii, Gibbsiella quercinecans, and Rahnella victoriana. With the microbes (B. goodwinii and G. quercinecans) and beetle larvae in hand, the researchers were able to replicate the characteristic signs of Acute Oak Decline. (more…)