Estimating genetic structure and diversity of cyanobacterial communities in Atlantic forest phyllosphere

Abstract

Cyanobacterial communities on the phyllosphere of 4 plant species inhabiting the endangered Brazilian Atlantic Forest biome were evaluated using cultivation-independent molecular approaches. Total genomic DNA was extracted from cells detached from the surface of leaves of Euterpe edulis, Guapira opposita, Garcinia gardneriana, and Merostachys neesii sampled in 2 Brazilian Atlantic Forest locations along an elevational gradient, i.e., lowland and montane forest. The DNA fingerprinting method PCR-DGGE revealed that the cyanobacterial phyllosphere community structures were mainly influenced by the plant species; geographical location of the plant had little effect. The 16S rRNA gene sequences obtained by clone libraries showed a predominance of nitrogen-fixing cyanobacteria of the order Nostocales, even though the majority of retrieved operational taxonomic units (∼60% of the sequences) showed similarity only to uncultured cyanobacteria phylotypes. The leaf surface of Guapira opposita had the highest richness and diversity of cyanobacteria, whereas the M. neesii (bamboo) had the largest number of copies of cyanobacterial 16S rRNA gene per cm of leaf. This study investigated cyanobacteria diversity and its distribution pattern in Atlantic forest phyllosphere. The results indicated that plant species is the main driver of cyanobacteria community assemblage in the phyllosphere and that these communities are made up of a high diversity of cyanobacterial taxa that need to be discovered.

Nitrogen input by bamboos in neotropical forest: a new perspective

“…M. neesii exhibits higher cyanobacteria abundance and a larger number of diazotrophs affiliated to the order Nostocales (Rigonato et al, 2016) than E. edulis and other species from the same area (Gómez, 2012). Its phyllosphere harbored high annual BNF rates (∼60 kg N ha −1 y −1 ), almost equal to the rate reported for evergreen tropical forests (Reed, Cleveland & Townsend, 2011), but significantly higher than those observed for Spathacanthus hoffmannii (Acanthaceae), Chamaedorea tepejilote (Arecaceae), Brosimum utile (Moraceae), Caryocar costaricense (Caryocaraceae), Staminodella manilkara (Sapotaceae), Qualea paraensis (Vochysiaceae) and Schizolobium parahybum (Fabaceae) (between 0.035 and 5 kg N ha −1 y −1 —Freiberg, 1998; Reed, Cleveland & Townsend, 2008).…”

“…Studying the same bamboo species, Rigonato et al (2016) reported a high abundance of cyanobacteria from the diazotrophic order Nostacales. In this AF area, unlike several other studies (Tabarelli & Mantovani, 2000; Griscom & Ashton, 2003; Lima et al, 2012), the presence of M. neesii in a pristine montane forest does not seem to alter the overall forest structure and diversity (Padgurschi et al, 2011), carbon and nitrogen stocks (Vieira et al, 2011) or tree biomass (283.2 Mg ha −1 ) (Alves et al, 2010).…”

“…Studies have shown that free-living BNF fixers in litter and those associated with the aerial parts of plants play a vital role in total N inputs in tropical forests (Bentley, 1987; Benner et al, 2007; Reed, Cleveland & Townsend, 2011). The leaf surfaces (phyllosphere) in these forests harbor a wide range of bacteria (Lambais et al, 2006; Fürnkranz et al, 2008; Lambais, Lucheta & Crowley, 2014), many of which are N fixers and dictate the patterns of N fixation rates (Reed, Cleveland & Townsend, 2011; Rigonato et al, 2016). …”

The importance of phyllosphere on plant functional ecology: a phyllo trait manifesto

“…However, bryophytes may also play a role in leaf nitrogen balance either by reciprocally transferring nitrogen to host leaves (Wanek & Portl, ) or creating favorable microclimatic conditions for cyanobacteria (Bentley, ; Turetsky, ). Microbial assemblages such as biofilms harboring cyanobacteria and other nitrogen fixing bacteria, including endophytic bacteria, might also transfer nitrogen to the leaf (Coley & Kursar, ; Moyes et al ., ; Rigonato et al ., ; Lambais et al ., ). In this line, Laforest‐Lapointe et al .…”

“…However, bryophytes may also play a role in leaf nitrogen balance either by reciprocally transferring nitrogen to host leaves (Wanek & Portl, 2005) or creating favorable microclimatic conditions for cyanobacteria (Bentley, 1987;Turetsky, 2003). Microbial assemblages such as biofilms harboring cyanobacteria and other nitrogen fixing bacteria, including endophytic bacteria, might also transfer nitrogen to the leaf (Coley & Kursar, 1996;Moyes et al, 2016;Rigonato et al, 2016;Lambais et al, 2017). In this line, Laforest-Lapointe et al (2017), using a tree biodiversity-ecosystem functioning experiment, have shown that plant community productivity is positively related to phyllosphere bacterial diversity indicating the importance of the interplay of plant-phyllosphere for ecosystem functioning.…”