Last updated June 28, 2018 at 9:52 am
Immune system helps oaks ward off disease.
Credit: Marilyna / iStock
Some of the world’s most majestic trees have been around for centuries, which raises the question of why something doesn’t kill them off earlier.
The answer, if the English or common oak is any guide, may be disease-resistance gene expansion.
An international team led by from Christophe Plomion from Université de Bordeaux in France sequenced, assembled and annotated the oak’s genome then compared it with existing whole-genome sequences for other plants, including trees and herbaceous sequences.
They discovered that the English oak experienced a recent burst of tandem gene duplication, which appears to have contributed to 73 per cent of its total gene family expansion. These expanded families, they say, are largely associated with disease-resistance genes and exhibit positive selection signatures.
And the oak is not unique in this regard. The authors found similar disease-resistance gene expansions in other tree genomes, relative to those of herbaceous species. They conclude that this parallel gene expansion suggests that the arboreal immune system plays a vital role in ensuring the trees’ longevity.
The paper published in Nature Plants.
