Drivers of Foliar Fungal Endophytic Communities of Kudzu (Pueraria montana var. lobata) in the Southeast United States

Abstract

Fungal endophytes play important roles in plant fitness and plant–microbe interactions. Kudzu (Pueraria montana var. lobata) is a dominant, abundant, and highly aggressive invasive plant in the Southeast United States. Kudzu serves as a pathogen reservoir that impacts economically important leguminous crops. We conducted the first investigations on kudzu fungal endophytes (Illumina MiSeq—ITS2) to elucidate drivers of endophytic communities across the heart of the invasive range in the Southeast United States (TN, MS, AL, GA). We tested the impacts of multiple environmental parameters (Chlorophyll, NO3−, K+, soil pH, leaf area, host genotype, traffic intensity, and geographic location) on foliar endophyte communities. Endophytic communities were diverse and structured by many factors in our PerMANOVA analyses, but location, genotype, and traffic (proxy for pollution) were the strongest drivers of community composition (R2 = 0.152, p < 0.001, R2 = 0.129, p < 0.001, and R2 = 0.126, p < 0.001, respectively). Further, we examined the putative ecological interactions between endophytic fungi and plant pathogens. We identify numerous OTUs that are positively and strongly associated with pathogen occurrence, largely within the families Montagnulaceae and Tremellales incertae sedis. Taken together, these data suggest location, host genetics and local pollution play instrumental roles in structuring communities, and integrative plant management must consider these factors when developing management strategies.

Comparative Analyses of Phyllosphere Bacterial Communities and Metabolomes in Newly Developed Needles of Cunninghamia lanceolata (Lamb.) Hook. at Four Stages of Stand Growth

“…The total leaf surface area greatly exceeds the terrestrial land area in forest ecosystems. Therefore, plant leaves and needles provide vast habitats for diverse bacteria and fungi, especially foliar endophytic fungi (Saucedo-Garcia et al, 2014 ; Jia et al, 2020 ; Quiring et al, 2020 ; Shahrtash and Brown, 2020 ) and bacteria (Rakotoniriana et al, 2013 ; Yu et al, 2015 ; Carrell et al, 2016 ). Foliar endophytes perform multiple functions (Jia et al, 2020 ) and participate in nutrient uptake (Madhaiyan et al, 2015 ; Moyes et al, 2016 ; Christian et al, 2019 ).…”

Unveiling the resistance of native weed communities: insights for managing invasive weed species in disturbed environments

“…Berihun et al (2021) recently drew attention to the role of anthropogenic activities in the spread of invasive weeds. For example, the introduction of Pueraria montana in North America as a forage crop resulted in its rapid spread and smothering of native vegetation (Silva et al, 2017;Shahrtash, 2022). Global trade and travel have greatly accelerated the introduction of non-native plants into new regions (Hulme, 2021).…”

A Path Forward: Promoting Microbial-Based Methods in the Control of Invasive Plant Species

“…However, most research on direct interactions between microbes and pathogens focuses on pathogen mitigation and symptom alleviation [ 8 , 99 ]. Investigations into microbial-mediated pathogen facilitation and increased pathogenicity have not been extensively studied but may have enormous potential to suppress invasive plants [ 16 ]. Some plant-associated microbes produce metabolites that can promote pathogen development and facilitate disease [ 100 ].…”

“…This facilitation may also be due to ecological interactions including competitive exclusion or niche partitioning [ 101 ]. By investigating and understanding the dynamics of the invasive plant micro- and mycobiomes, we can develop strategies for modification and manipulation of these communities [ 16 ] to favor successful colonization and growth of taxa that facilitate pathogen virulence, or taxa that negatively impact invasive PGPMs, thus resulting in suppression in invasive plants and a reduction in plant fitness. This is an emerging field of study, but one that we feel will be of increasing importance with a growing emphasis on sustainable and non-chemical controls of invasive plants [ 15 ].…”

“…However, complex multi-partite microbe–microbe interactions within plants can act in unforeseen ways to limit or modulate targeted goals. Plant-microbiome manipulative investigations are underexplored but have been suggested as a novel tool for invasive plant management [ 16 ]. Here, we argue that microbiome manipulations can be a powerful tool for helping to control invasive plants, but this emerging application has hitherto been underutilized and poorly studied.…”