Fundamental questions
Fungal endophytes provide ecological functions for their host plants, including promotion of plant growth, inhibition of plant pathogens and drought tolerance, which are all characteristics that have potential far-reaching agricultural use. However, the way in which endophyte communities across the major terrestrial plant lineages respond to seasonal water stress is a question that has not yet been examined in tropical endophytes using culture-independent methods. The lowland rainforests of the Iron Range in north-eastern Australia experience extreme seasonal fluctuations in water availability due to the monsoon cycle and unique regional geology. The aims of this study are to (a) establish how fungal endophyte diversity and community composition differs during the dry and wet seasons in the monsoon tropics, and (b) whether endophytes of host plants representing the major lineages in Embryophyta exhibit different community-level responses to seasonal water scarcity and abundance. This information has the potential to direct agriculture-focused bioprospecting efforts to isolate beneficial fungal endophytes from the Australian tropics, and to clarify the degree to which land plants have developed divergent microbiomes over deep evolutionary time. We compared the fungal microbiomes of plants in northern Australia sampled from wet and dry seasons, performing ITS metabarcoding on fungal communities in leaves and stems of 12 plant taxa, including angiosperms, monocots, magnoliids and bryophytes.