Host and environmental determinants of microbial community structure in the marine phyllosphere

Abstract

Although seagrasses are economically and ecologically critical species, little is known about their blade surface microbial communities and how these communities relate to the plant host. To determine microbial community composition and diversity on seagrass blade surfaces and in the surrounding seawater,16S rRNA gene sequencing (iTag) was used for samples collected at five sites along a gradient of freshwater input in the northern Gulf of Mexico on three separate sampling dates. Additionally, seagrass surveys were performed and environmental parameters were measured to characterize host characteristics and the abiotic conditions at each site. Results showed that Thalassia testudinum (turtle grass) blades hosted unique microbial communities that were distinct in composition and diversity from the water column. Environmental conditions, including water depth, salinity, and temperature, influenced community structure as blade surface microbial communities varied among sites and sampling dates in correlation with changes in environmental parameters. Microbial community composition also correlated with seagrass host characteristics, including growth rates and blade nutrient composition. There is some evidence for a core community for T. testudinum as 21 microorganisms from five phyla (Cyanobacteria, Proteobacteria, Planctomycetes, Chloroflexi, and Bacteroidetes) were present in all blade surface samples. This study provides new insights and understanding of the processes that influence the structure of marine phyllosphere communities, how these microbial communities relate to their host, and their role as a part of the seagrass holobiont, which is an important contribution given the current decline of seagrass coverage worldwide.

Diversity and Composition of Microbial Communities in an Eelgrass (<i>Zostera marina</i>) Bed in Tokyo Bay, Japan

“…, seawater and sediment) as well as in seagrass samples (including the leaves and roots). These results are consistent with previous findings showing differences in microbial compositions not only between leaves and the rooting zone ( Crump and Koch, 2008 ; Ettinger et al , 2017 ; Fahimipour et al , 2017 ), but also between seagrass and the surrounding environment ( Jensen et al , 2007 ; Gordon-Bradley et al , 2014 ; Cúcio et al , 2016 ; Mejia et al , 2016 ; Crump et al , 2018 ; Hurtado-McCormick et al , 2019 ; Vogel et al , 2020 ). The classes Alphaproteobacteria and Gammaproteobacteria were dominant on the surface of Z. marina green healthy leaves ( Table S2 and Fig.…”

“…In contrast to land plants, limited information is currently available on the microbes associated with aquatic angiosperms, such as seagrass. Recent culture-independent studies have focused on relationships with general sediment bacteria in the seagrass rhizosphere ( Cifuentes et al , 2000 ; James et al , 2006 ; Green-García and Engel, 2012 ; Sun et al , 2015 ; Cúcio et al , 2016 ; Zhang et al , 2020 ), epiphytic microbes on Hallophila stipulacea ( Mejia et al , 2016 ), and comparisons of seagrass microbes with those of surrounding environments in Z. marina , Zostera Japonica , Zostera muelleri ( Ettinger et al , 2017 ; Fahimipour et al , 2017 ; Crump et al , 2018 ; Hurtado-McCormick et al , 2019 ), Thalassia testudinum , and Syringodium filliforme beds ( Ugarelli et al , 2019 ; Vogel et al , 2020 ). The majority of community analyses revealed that the taxonomical composition of microbial communities varied among seagrass tissues, namely, leaves and the root-rhizome ( Crump and Koch, 2008 ; Mejia et al , 2016 ; Ettinger et al , 2017 ; Fahimipour et al , 2017 ).…”

“…The majority of community analyses revealed that the taxonomical composition of microbial communities varied among seagrass tissues, namely, leaves and the root-rhizome ( Crump and Koch, 2008 ; Mejia et al , 2016 ; Ettinger et al , 2017 ; Fahimipour et al , 2017 ). Furthermore, the composition of microbial communities differed between seagrass bodies and the surrounding environments ( Jensen et al , 2007 ; Cúcio et al , 2016 ; Mejia et al , 2016 ; Crump et al , 2018 ; Hurtado-McCormick et al , 2019 ; Vogel et al , 2020 ). In contrast, a recent study on eelgrass microbiomes showed that leaf communities appeared to be similar to those of the surrounding seawater ( Fahimipour et al , 2017 ).…”

Bacillus velezensis SYL-3 suppresses Alternaria alternata and tobacco mosaic virus infecting Nicotiana tabacum by regulating the phyllosphere microbial community

“…The changes in the structure and composition of the phyllosphere microbial community are closely correlated with the impact of the external environment on the host plant ( Vogel et al, 2020 ). At the genus level, we analyzed the phyllosphere microbial community structure in the control and SYL-3-treated groups on day 21 after treatment.…”

Microbial communities on eelgrass (Zostera marina) thriving in Tokyo Bay and the possible source of leaf-attached microbes

“…Another study identified epiphytic microbial communities on three seagrass species from the East African coast (Uku et al, 2007). Recently, some culture-independent surveys of seagrass epiphytic microbes have been published (Mejia et al, 2016;Ettinger et al, 2017;Fahimipour et al, 2017;Crump et al, 2018;Hurtado-McCormick et al, 2019, 2020Ugarelli et al, 2019;Vogel et al, 2020;Iqbal et al, 2021;Rabbani et al, 2021). Most community analyses revealed that microbial communities varied in microbial composition with seagrass tissues: leaves and the root-rhizome (Mejia et al, 2016;Ettinger et al, 2017;Fahimipour et al, 2017;Crump et al, 2018;Ugarelli et al, 2019;Iqbal et al, 2021).…”