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Different pioneer plant species select specific rhizosphere bacterial communities in a high mountain environment.

Ciccazzo S, Esposito A, Rolli E, Zerbe S, Daffonchio D, Brusetti L - Springerplus (2014)

Bottom Line: The rhizobacterial communities of 29 pioneer plants belonging to 12 species were investigated in an alpine ecosystem to assess if plants from different species could select for specific rhizobacterial communities.Rhizospheres and unvegetated soils were collected from a floristic pioneer stage plot at 2,400 m a.s.l. in the forefield of Weisskugel Glacier (Matsch Valley, South Tyrol, Italy), after 160 years of glacier retreat.ARISA fingerprinting showed that rhizobacterial genetic structure was extremely different from bare soil bacterial communities while rhizobacterial communities clustered strictly together according to the plant species.

View Article: PubMed Central - PubMed

Affiliation: DeFENS, Department of Food, Environmental and Nutritional Sciences, University of Milan, via Celoria 2, 20133 Milan, Italy.

ABSTRACT
The rhizobacterial communities of 29 pioneer plants belonging to 12 species were investigated in an alpine ecosystem to assess if plants from different species could select for specific rhizobacterial communities. Rhizospheres and unvegetated soils were collected from a floristic pioneer stage plot at 2,400 m a.s.l. in the forefield of Weisskugel Glacier (Matsch Valley, South Tyrol, Italy), after 160 years of glacier retreat. To allow for a culture-independent perspective, total environmental DNA was extracted from both rhizosphere and bare soil samples and analyzed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and Denaturing Gradient Gel Electrophoresis (DGGE). ARISA fingerprinting showed that rhizobacterial genetic structure was extremely different from bare soil bacterial communities while rhizobacterial communities clustered strictly together according to the plant species. Sequencing of DGGE bands showed that rhizobacterial communities were mainly composed of Acidobacteria and Proteobacteria whereas bare soil was colonized by Acidobacteria and Clostridia. UniFrac significance calculated on DGGE results confirmed the rhizosphere effect exerted by the 12 species and showed different bacterial communities (P < 0.05) associated with all the plant species. These results pointed out that specific rhizobacterial communities were selected by pioneer plants of different species in a high mountain ecosystem characterized by oligotrophic and harsh environmental conditions, during an early primary succession.

No MeSH data available.


Related in: MedlinePlus

ARISA peaks relative abundance within samples. Stacked barcharts representing the relative abundance of group of ARISA peaks given in base pairs (bp), associated to the 12 pioneer plant species rhizosphere and to the unvegetated soil. Acronyms list name as follows: unvegetated soil; Potentilla aurea; Sibbaldia procumbens; Festuca halleri; Senecio carniolicus; Silene acaulis; Leucanthemopsis alpina; Minuartia sedoides; Gnaphalium supinum; Veronica bellidioides; Linaria alpina; Sedum alpestre; Saxifraga bryoides.
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Fig1: ARISA peaks relative abundance within samples. Stacked barcharts representing the relative abundance of group of ARISA peaks given in base pairs (bp), associated to the 12 pioneer plant species rhizosphere and to the unvegetated soil. Acronyms list name as follows: unvegetated soil; Potentilla aurea; Sibbaldia procumbens; Festuca halleri; Senecio carniolicus; Silene acaulis; Leucanthemopsis alpina; Minuartia sedoides; Gnaphalium supinum; Veronica bellidioides; Linaria alpina; Sedum alpestre; Saxifraga bryoides.

Mentions: The electropherograms, characterized by distinct peaks number and intensity, revealed a large shift in bacterial community structure across the different plant species (Figure 1). The unvegetated soils revealed a high degree of similarity among replicates. They were different from rhizobacterial communities’ structure and more than 92% of their peaks were evenly distributed between 279–981 bp. The rhizobacterial communities showed distinctive peak patterns according to plant species. Ln. alpina exhibited a profile characterized by more than 20% of peaks between 155–280 bp and the most of bands distributed up to 643 bp. F. halleri had 10% of peaks between 155–280 bp, but more evenly distributed peaks until 807 bp, while G. supinum is the only species without peaks between 155–280 bp. Peaks between 279–331 represents 16% in S. bryoides. Peaks between 384–434 bp were the major peaks in P. aurea whereas peaks between 435–488 bp were the most abundant in S. procumbens and peaks between 489–541 bp were present in good percentage in P. aurea, S. carniolicus, S. acaulis, Lc. alpina, V. bellidioides and M. sedoides. Anyway, S. acaulis and S. alpestre were mainly characterized by peaks up to 592 bp. Comparing the unvegetated soil samples with all the 29 rhizosphere samples, PERMANOVA confirmed significantly different microbial community structures (F = 1.58; P < 0.007). Pairwise comparison of bulk soil and single plant species showed that pioneer plant species hosted a specific rhizobacterial community, except for G. supinum and V. bellidioides (P = 0.094; Table 1).Figure 1


Different pioneer plant species select specific rhizosphere bacterial communities in a high mountain environment.

Ciccazzo S, Esposito A, Rolli E, Zerbe S, Daffonchio D, Brusetti L - Springerplus (2014)

ARISA peaks relative abundance within samples. Stacked barcharts representing the relative abundance of group of ARISA peaks given in base pairs (bp), associated to the 12 pioneer plant species rhizosphere and to the unvegetated soil. Acronyms list name as follows: unvegetated soil; Potentilla aurea; Sibbaldia procumbens; Festuca halleri; Senecio carniolicus; Silene acaulis; Leucanthemopsis alpina; Minuartia sedoides; Gnaphalium supinum; Veronica bellidioides; Linaria alpina; Sedum alpestre; Saxifraga bryoides.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4125605&req=5

Fig1: ARISA peaks relative abundance within samples. Stacked barcharts representing the relative abundance of group of ARISA peaks given in base pairs (bp), associated to the 12 pioneer plant species rhizosphere and to the unvegetated soil. Acronyms list name as follows: unvegetated soil; Potentilla aurea; Sibbaldia procumbens; Festuca halleri; Senecio carniolicus; Silene acaulis; Leucanthemopsis alpina; Minuartia sedoides; Gnaphalium supinum; Veronica bellidioides; Linaria alpina; Sedum alpestre; Saxifraga bryoides.
Mentions: The electropherograms, characterized by distinct peaks number and intensity, revealed a large shift in bacterial community structure across the different plant species (Figure 1). The unvegetated soils revealed a high degree of similarity among replicates. They were different from rhizobacterial communities’ structure and more than 92% of their peaks were evenly distributed between 279–981 bp. The rhizobacterial communities showed distinctive peak patterns according to plant species. Ln. alpina exhibited a profile characterized by more than 20% of peaks between 155–280 bp and the most of bands distributed up to 643 bp. F. halleri had 10% of peaks between 155–280 bp, but more evenly distributed peaks until 807 bp, while G. supinum is the only species without peaks between 155–280 bp. Peaks between 279–331 represents 16% in S. bryoides. Peaks between 384–434 bp were the major peaks in P. aurea whereas peaks between 435–488 bp were the most abundant in S. procumbens and peaks between 489–541 bp were present in good percentage in P. aurea, S. carniolicus, S. acaulis, Lc. alpina, V. bellidioides and M. sedoides. Anyway, S. acaulis and S. alpestre were mainly characterized by peaks up to 592 bp. Comparing the unvegetated soil samples with all the 29 rhizosphere samples, PERMANOVA confirmed significantly different microbial community structures (F = 1.58; P < 0.007). Pairwise comparison of bulk soil and single plant species showed that pioneer plant species hosted a specific rhizobacterial community, except for G. supinum and V. bellidioides (P = 0.094; Table 1).Figure 1

Bottom Line: The rhizobacterial communities of 29 pioneer plants belonging to 12 species were investigated in an alpine ecosystem to assess if plants from different species could select for specific rhizobacterial communities.Rhizospheres and unvegetated soils were collected from a floristic pioneer stage plot at 2,400 m a.s.l. in the forefield of Weisskugel Glacier (Matsch Valley, South Tyrol, Italy), after 160 years of glacier retreat.ARISA fingerprinting showed that rhizobacterial genetic structure was extremely different from bare soil bacterial communities while rhizobacterial communities clustered strictly together according to the plant species.

View Article: PubMed Central - PubMed

Affiliation: DeFENS, Department of Food, Environmental and Nutritional Sciences, University of Milan, via Celoria 2, 20133 Milan, Italy.

ABSTRACT
The rhizobacterial communities of 29 pioneer plants belonging to 12 species were investigated in an alpine ecosystem to assess if plants from different species could select for specific rhizobacterial communities. Rhizospheres and unvegetated soils were collected from a floristic pioneer stage plot at 2,400 m a.s.l. in the forefield of Weisskugel Glacier (Matsch Valley, South Tyrol, Italy), after 160 years of glacier retreat. To allow for a culture-independent perspective, total environmental DNA was extracted from both rhizosphere and bare soil samples and analyzed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and Denaturing Gradient Gel Electrophoresis (DGGE). ARISA fingerprinting showed that rhizobacterial genetic structure was extremely different from bare soil bacterial communities while rhizobacterial communities clustered strictly together according to the plant species. Sequencing of DGGE bands showed that rhizobacterial communities were mainly composed of Acidobacteria and Proteobacteria whereas bare soil was colonized by Acidobacteria and Clostridia. UniFrac significance calculated on DGGE results confirmed the rhizosphere effect exerted by the 12 species and showed different bacterial communities (P < 0.05) associated with all the plant species. These results pointed out that specific rhizobacterial communities were selected by pioneer plants of different species in a high mountain ecosystem characterized by oligotrophic and harsh environmental conditions, during an early primary succession.

No MeSH data available.


Related in: MedlinePlus