Environment–host–microbial interactions shape the Sarraceniapurpurea microbiome at the continental scale

Abstract

The importance of climate, habitat structure, and higher trophic levels on microbial diversity is only beginning to be understood. Here, we examined the influence of climate variables, plant morphology, and the abundance of aquatic invertebrates on the microbial biodiversity of the northern pitcher plant Sarracenia purpurea. The plant's cup-shaped leaves fill with rainwater and support a miniature, yet full-fledged ecosystem with a diverse microbiome that decomposes captured prey and a small network of shredding and filter-feeding aquatic invertebrates that feed on microbes. We characterized pitcher microbiomes of 108 plants sampled at 36 sites from Florida to Quebec. Structural equation models revealed that annual precipitation and temperature, plant size, and midge abundance had direct effects on microbiome taxonomic and phylogenetic diversity. Climate variables also exerted indirect effects through plant size and midge abundance. Further, spatial structure and climate influenced taxonomic composition, but not phylogenetic composition. Our results suggest that direct effects of midge abundance and climate and indirect effects of climate through its effect on plant-associated factors lead to greater richness of microbial phylotypes in warmer, wetter sites.

Cultivated and wild pearl millet display contrasting patterns of abundance and co-occurrence in their root mycobiome

“…Through their different trophic modes, the root-associated fungi can interact directly or indirectly with each other positively or negatively, and thereby influence the fitness of their host plant 18 – 20 . On the other hand, it has been established that host genotype and environment factors shape microbiome assembly in natural environments 20 – 22 .…”

Exploring Microbiome Functional Dynamics through Space and Time with Trait-Based Theory

“…Further extending the Y-A-S framework across a biogeographical gradient, we consider the latitudinal diversity gradient (LDG), where decreases in species richness from the equator to the poles have been well-established for many plants and animals ( 20 , 21 ), although there is mixed support for microbes ( 22 , 23 ). Hypotheses for the LDG (e.g., greater productivity, more stable climate, warmer temperatures in the tropics, etc.)…”

“…The leaves of the plant are sterile when they open, and the recruitment of their microbiome represents the start of succession, which can be followed throughout the growing season of the plant ( 45 , 46 ). S. purpurea inhabits a large latitudinal gradient, ranging from Florida to Canada ( 23 ) ( Fig. 2A ), with microbiome richness exhibiting a negative relationship with latitude that is predicted by the latitudinal diversity gradient (LDG) ( 23 ).…”

“…S. purpurea inhabits a large latitudinal gradient, ranging from Florida to Canada ( 23 ) ( Fig. 2A ), with microbiome richness exhibiting a negative relationship with latitude that is predicted by the latitudinal diversity gradient (LDG) ( 23 ). The wide distribution and observed LDG provide opportunities to examine biogeographical factors driving microbiome functions.…”

Bacterial Recruitment to Carnivorous Pitcher Plant Communities: Identifying Sources Influencing Plant Microbiome Composition and Function

“…Investigation of the Sarracenia invertebrate food web structure and function suggests convergence of diversity and taxonomic composition over the growing season ( Miller and TerHorst, 2012 ). In the Sarracenia microbial communities, functions can vary across geographically separated populations of pitchers ( Bittleston et al, 2016 , 2021 ; Grothjan and Young, 2019 ; Freedman et al, 2021 ) and over time in Darlingtonia pitcher plants ( Armitage, 2017 ). However, the roles of different bacterial sources, including rainwater, air, and prey capture, contributing functionally important taxa to the assemblages remains understudied in the Sarracenia microbial food web.…”