Endophytes of Apple: Understanding Endophytes to improve tree health

Endophytes are microorganisms which live within the plant without causing apparent disease. Endophytes are well known in other plant host species as agents which can enhance resistance to biotic attack, enhance stress tolerance and increase growth. Although the host-endophyte interaction tends to be mutualistic (both partners benefit), other ‘shades’ of endophytism include commensals (offer no benefit to host), latent pathogens and latent saprophytes.

Neonectria ditissima, the causative agent of European apple canker has been increasing in significance on a global scale. As part of a larger body of work focusing on canker we aim to examine if N.ditissima resides as an endophyte in the host before switching to a pathogenic phase when the host experiences abiotic stress, i.e. during the establishment phase of newly planted orchards. The student will utilise next generation sequencing technologies to determine the endophytic profile of apple, conducting experiments to determine what factors influence the profile and whether this is associated with disease expression. Newly available serological tools will be used to increase our understanding of asymptomatic infection. With this knowledge the student will explore ways to exploit endophytes to increase plant health. This work will provide a breakthrough in our understanding of this important disease and will present new opportunities for disease management through the following deliverables; (1) determining the endophyte profile of apple and factors which influence it (2) the locality and timing of asymptomatic infection (3) the validation of a diagnostic tool and sampling procedure (4) increasing plant health through manipulation of endophytes. 

Further reading

Limited asymptomatic colonization of apple tree shoots by Neonectria ditissima following infection of leaf scars and pruning wounds – Plant Pathology Original Article – Open Access