Fire impacts bacterial composition in Protea repens (Proteaceae) infructescences

The diverse bacterial communities in and around plants provide important benefits, such as protection against pathogens and cycling of essential minerals through decomposition of moribund plant biomass. Biodiverse fynbos landscapes generally have limited deadwood habitats due to the absence of large trees and frequent fire. In this study, we determined the effect of a fire disturbance on the bacterial communities in a fynbos landscape dominated by the shrub Protea repens using 16S ribosomal RNA amplicon sequencing. The bacterial community composition in newly formed fruiting structures (infructescences) and soil at a recently burnt site was different from that in an unburnt site. Bacteria inhabiting P. repens infructescences were similar to well-known taxa from decomposing wood and litter. This suggests a putative role for these aboveground plant structures as reservoirs for postfire decomposer bacteria. The results imply that inordinately frequent fires, which are commonplace in the Anthropocene, are a significant disturbance to bacterial communities and could affect the diversity of potentially important microbes from these landscapes.The National Research Foundation (NRF) and the Department of Science and Innovation (DSI)/NRF Centre of Excellence in Tree Health Biotechnology (CTHB).https://academic.oup.com/femsle2022-10-09hj2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Antifungal Streptomyces spp. associated with the infructescences of Protea spp. in South Africa

Common saprophytic fungi are seldom present in Protea infructescences, which is strange given the abundance of mainly dead plant tissue in this moist protected environment. We hypothesized that the absence of common saprophytic fungi in Protea infructescences could be due to a special symbiosis where the presence of microbes producing antifungal compounds protect the infructescence. Using a culture based survey, employing selective media and in vitro antifungal assays, we isolated antibiotic producing actinomycetes from infructescences of Protea repens and P. neriifolia from two geographically separated areas. Isolates were grouped into three different morphological groups and appeared to be common in the Protea spp. examined in this study. The three groups were supported in 16S rRNA and multi-locus gene trees and were identified as potentially novel Streptomyces spp. All of the groups had antifungal activity in vitro. Streptomyces sp. Group 1 had inhibitory activity against all tested fungi and the active compound produced by this species was identified as fungichromin. Streptomyces spp. Groups 2 and 3 had lower inhibition against all tested fungi, while Group 3 showed limited inhibition against Candida albicans and Sporothrix isolates. The active compound for Group 2 was also identified as fungichromin even though its production level was much lower than Group 1. The antifungal activity of Group 3 was linked to actiphenol. The observed antifungal activity of the isolated actinomycetes could contribute to protection of the plant material against common saprophytic fungi, as fungichromin was also detected in extracts of the infructescence. The results of this study suggest that the antifungal Streptomyces spp. could play an important role in defining the microbial population associated with Protea infructescences.The Department of Science and Technology (DST)-National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB), the National Research Foundation (NRF), the University of Pretoria, South Africa as well as by a National Research Foundation of Korea Grant funded by the Korean Government (Ministry of ICT and Future Planning; No. 2014R1A2A1A11053477). Remove selectedhttp://www.frontiersin.org/Forestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Antifungal Streptomyces spp. associated with the infructescences of Protea spp. in South Africa

Common saprophytic fungi are seldom present in Protea infructescences, which is strange given the abundance of mainly dead plant tissue in this moist protected environment. We hypothesized that the absence of common saprophytic fungi in Protea infructescences could be due to a special symbiosis where the presence of microbes producing antifungal compounds protect the infructescence. Using a culture based survey, employing selective media and in vitro antifungal assays, we isolated antibiotic producing actinomycetes from infructescences of Protea repens and P. neriifolia from two geographically separated areas. Isolates were grouped into three different morphological groups and appeared to be common in the Protea spp. examined in this study. The three groups were supported in 16S rRNA and multi-locus gene trees and were identified as potentially novel Streptomyces spp. All of the groups had antifungal activity in vitro. Streptomyces sp. Group 1 had inhibitory activity against all tested fungi and the active compound produced by this species was identified as fungichromin. Streptomyces spp. Groups 2 and 3 had lower inhibition against all tested fungi, while Group 3 showed limited inhibition against Candida albicans and Sporothrix isolates. The active compound for Group 2 was also identified as fungichromin even though its production level was much lower than Group 1. The antifungal activity of Group 3 was linked to actiphenol. The observed antifungal activity of the isolated actinomycetes could contribute to protection of the plant material against common saprophytic fungi, as fungichromin was also detected in extracts of the infructescence. The results of this study suggest that the antifungal Streptomyces spp. could play an important role in defining the microbial population associated with Protea infructescences.The Department of Science and Technology (DST)-National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology (CTHB), the National Research Foundation (NRF), the University of Pretoria, South Africa as well as by a National Research Foundation of Korea Grant funded by the Korean Government (Ministry of ICT and Future Planning; No. 2014R1A2A1A11053477). Remove selectedhttp://www.frontiersin.org/Forestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

A meta-analysis of global fungal distribution reveals climate-driven patterns.

The evolutionary and environmental factors that shape fungal biogeography are incompletely understood. Here, we assemble a large dataset consisting of previously generated mycobiome data linked to specific geographical locations across the world. We use this dataset to describe the distribution of fungal taxa and to look for correlations with different environmental factors such as climate, soil and vegetation variables. Our meta-study identifies climate as an important driver of different aspects of fungal biogeography, including the global distribution of common fungi as well as the composition and diversity of fungal communities. In our analysis, fungal diversity is concentrated at high latitudes, in contrast with the opposite pattern previously shown for plants and other organisms. Mycorrhizal fungi appear to have narrower climatic tolerances than pathogenic fungi. We speculate that climate change could affect ecosystem functioning because of the narrow climatic tolerances of key fungal taxa