Has Antimicrobial Production Shaped Fungal Endophyte Diversification

Fungal endophytes, inhabitants of plant tissues which cause no symptoms, are a major group of hyperdiverse microfungi. They are omnipresent in plants. While most endophyte research has centred on evolutionary benefits for plants and discovery of bioactive molecules (antibiotics, insecticides, etc.), we plan to explore the evolutionary drivers of adaptation and the innovations which have contributed to diversification of endophytic fungi.

We hypothesise that a key driver is the development and maintenance of antimicrobial production by the dual means of: (1) a host environment suppresses rapid growth, thereby favouring inhibition over nutritional efficiency and (2) once antimicrobial production is established, only those fungi that can resist the antimicrobials present can effectively compete. Resistance to antimicrobials is often packaged genetically with antimicrobial production, favouring persistent antimicrobial activity in the plant without any plant driven selection, a process known as ‘competitive phenotypic screening’.

We aim to test these hypotheses using a combination of broad-scale and fine-scale phylogenomic comparisons facilitated by the Fungal Tree of Life (FToL) along with experimental tests of antimicrobial activity and adaptive laboratory experiments in the Milner Centre for Evolution (i.e., lab test of the evolutionary process).

This project is a collaboration between Kew and Bath partners that seeks to understand how evolution has shaped the antimicrobial properties of fungal endophytes, fungi that live inside plants with no immediate symptoms. There is strong evidence that that these endophytes can provide protective effects against plant disease, but there is a much yet to be discovered about their identity and how natural selection has shaped their biology. This project focuses on isolation of specific lineages of these fungi, assessments of their antimicrobial production, and evolution experiments that capture how their genomes change in response to competition. The studentship will build new collections of biological material, conduct novel analyses, and gather data about antimicrobial molecules as well as answering basic ecological and evolutionary biology questions.