HOME  »  Members  »  Collaborators  »  PhD Students/Fellows
 
title Culturable endophytic bacteria from salt marsh plant Halimione portulacoides: functional characterization, phylogenetic diversity and influence of metal contamination
authors Fidalgo C, Tacão M, Rocha J, Henriques I, Alves A
title Culturable endophytic bacteria from salt marsh plant Halimione portulacoides: functional characterization, phylogenetic diversity and influence of metal contamination
nationality internacional
language English
document type Poster
conference title 13th Symposium on Bacterial Genetics and Ecology (BAGECO 13)
conference date 14-18th June
conference location Milan, Italy
author keywords Endophytic bacteria, Plant growth promotion, bacterial diversity
abstract Halimione portulacoides is one of the most productive and abundant species in salt marshes. This halophyte tolerates and accumulates mercury (Hg) and was proposed as a biomonitor for Hg pollution and phytoremediation purposes. Endophytic bacteria improve plant growth, stress tolerance and are a source of compounds with industrial applications. However, information about endophytic bacteria from H. portulacoides is scarce. We characterized 665 endophytic bacterial isolates of this halophyte from Hg -contaminated sites (B and E) and a noncontaminated site (C), from above (AG) and below ground (BG) tissues, in the estuary Ria de Aveiro. PCR-based fingerprinting yielded 467 representative isolates which were identified by 16S rDNA sequencing, and subjected to plant growth promotion (PGP) traits assays. The collection associated with 4 phyla: Proteobacteria 64%, Actinobacteria 23%, Firmicutes 10% and Bacteroidetes 3%. No site or tissue-level significant differences were found in OTU-based analysis, however there were noteworthy differences in some genera: Salinicola spp. isolates (58) were only obtained from site C; Hoefla (17), Labrenzia (22) and Microbacterium (67) were only isolated from BG tissues. Sequence-based UniFrac and principal coordinates analysis of isolates showed that diversity in BG tissues from all sites grouped together, and that the contamination factor was not relevant in the separation of bacterial communities. Many isolates from the collection tested positive for PGP assays. Remarkably, IAA production was detected in 99% of isolates. Site-level differences in proportion of positive isolates were observed: more proteolytic activity in site C; stronger presence of nifH gene in site E; more ACC deaminase activity in site B. Tissue-level differences were also observed: more pectinolytic activity in AG tissues and ACC deaminase activity in BG tissues. This study explored and exposed structural and functional variations in different tissues of a relevant halophyte in Hg contaminated and non-contaminated sites.
e-mail address cifidalgo@ua.pt
orcid number orcid.org/0000-0002-7064-4966
funding agency and grant number Fundação para a Ciência e Tecnologia (SFRH/BD/85423/2012; PTDC/AAC-AMB/118873/2010-FCOMP-01-0124-FEDER-019328)
year published 2015
file posterbagecocf.pdf