Rhizosphere effect and salinity competing to shape microbial communities inPhragmites australis(Cav.) Trin. ex-Steud

Abstract

Rhizobacterial communities associated with Phragmites australis (Cav.) Trin. ex Steud. in a hypersaline pond close to Wuliangsuhai Lake (Inner Mongolia - China) were investigated and compared with the microbial communities in bulk sediments of the same pond. Microbiological analyses have been done by automated ribosomal intergenic spacer analysis (ARISA) and partial 16S rRNA gene 454 pyrosequencing. Although community richness was higher in the rhizosphere samples than in bulk sediments, the salinity seemed to be the major factor shaping the structure of the microbial communities. Halanaerobiales was the most abundant taxon found in all the different samples and Desulfosalsimonas was observed to be present more in the rhizosphere rather than in bulk sediment.

Rhizobacterial communities of five co-occurring desert halophytes

“…In this study, bacterial communities differed between the rhizosphere and bulk soils, with higher community diversity and richness in the rhizosphere, consistent with previous studies (Avis et al, 2008; Borruso et al, 2014; Edwards et al, 2015; Chaudhary et al, 2017; Yang et al, 2017). Higher diversity may be a result of root exudates, which can raise nutrient concentrations (Li et al, 2014).…”

“…Only four genera, Acinetobacter , Citrobacter , Exiguobacterium and Pseudomonas , were common, which differs from the bacterial communities of saline soils in Inner Mongolia (Borruso et al, 2014) and the Shandong Peninsula coast (Tian & Zhang, 2017). Differences in community composition may be due to distinct climatic and/or soil properties among geographic regions (Ben-David et al, 2011).…”

“…Similar rhizobacterial communities may be found in different environments when the same plant species is present (Smalla et al, 2001; Berg & Smalla, 2009). However, in certain environments, such as hypersaline soils, plant species identity plays only a minor role compared to soil salinity in shaping microbial community structure (Borruso et al, 2014); this result has been confirmed by studies of desert soils (Li et al, 2013). Overall, both plant species identity and soil type can be important, depending on abiotic and biotic conditions (Berg & Smalla, 2009).…”

“…Many microorganisms have plant growth-promoting activities and confer salt tolerance on halophytic plants (Nabti et al, 2007; Sgroy et al, 2009; Jha, Gontia & Hartmann, 2012; Mapelli et al, 2013). Recent studies of halophyte-associated microbial communities have addressed the ecological and environmental drivers underlying community assembly and recruitment (Jha, Gontia & Hartmann, 2012; Borruso et al, 2014; Marasco et al, 2016; Chaudhary et al, 2017; Tian & Zhang, 2017). These studies have revealed that bacterial communities in the halophyte rhizosphere are distinctly different from those of non-halophytic plants, containing a larger proportion of halophilic bacteria (Al-Mailem et al, 2010).…”

Salicornia strobilacea (Synonym of Halocnemum strobilaceum) Grown under Different Tidal Regimes Selects Rhizosphere Bacteria Capable of Promoting Plant Growth

“…Soil and sediment bacterial communities are subjected to the influence of multiple environmental parameters that shape their composition in terms of taxa and their relative abundance (Fierer and Jackson, 2006; Fierer et al, 2012; Dini-Andreote et al, 2014), especially under “extreme” physico-chemical conditions (CAREX, 2011; Marteinsson et al, 2013; Borruso et al, 2014). Instead, rhizosphere is a particular habitat where plant root exudates can gradually alters the sediment conditions to select and enrich a specific rhizo-microbiome (Berg and Smalla, 2009; Dennis et al, 2010; Lundberg et al, 2012; Marasco et al, 2013a).…”