TY - JOUR
T1 - The effects of plant type, AMF inoculation and water regime on rhizosphere microbial communities
AU - Monokrousos, N.
AU - Papaptheodorou, Efimia
AU - Orfanoudakis, Michael
AU - Gwynn-Jones, D.
AU - Scullion, John
AU - Stamou, G. P.
N1 - Funding Information:
This work was supported by the Research Committee of Aristotle University of Thessaloniki (No. project 50141). We would like to thank the Laboratory of Plant Pathology of the Agriculture School, AUTh University and especially Professor U. Menkissoglu-Spiroudi for her help with PLFA identification. We also thank the Editor in Chief (Margaret Oliver) for her constructive criticism. Dylan Gwynn-Jones and John Scullion acknowledge the financial support provided by the Welsh Government and Higher Education Funding Council for Wales through the Sêr Cymru National Research Network for Low Carbon, Energy, and Environment and the BBSRC for supporting IBERS research.
Publisher Copyright:
© 2019 British Society of Soil Science
PY - 2020/3/3
Y1 - 2020/3/3
N2 - Different plant species, water regimes and microbes in the rhizosphere might shape rhizosphere microbial communities due to their effects on root exudation patterns and interactions. In this study, we investigated whether rhizosphere microbial communities have distinct structures according to plant type (Festuca pratensis, Dactylis glomerata or a mixture of both species), water regime (dry and wet pots) and inoculation with the arbuscular mycorrhizal fungus Rhizophagus irregularis (AMF). Following a 60-day pot experiment we assessed the rhizosphere microbial population structure via phospholipid fatty acids (PLFAs) and soil processes via the activity of N-acetyl-glucosaminidase (NAG), acid phosphatase and urease, and inorganic nitrogen (N) and phosphorus (P). Higher AMF colonization was recorded in F. pratensis, although its root and shoot biomass was lower than in D. glomerata. Although growth differed between the plant types, this exerted no influence on rhizosphere microbial biomass. Low water content decreased the biomass of all microbial groups, whereas inoculation with AMF decreased the biomass of fungi and increased that of bacteria. For enzyme activities only urease showed a response to treatments. Arbuscular mycorrhizal fungi inoculation increased available P and shifted mineral N content from nitrate to ammonium. The water regime had a dominant effect on the structure of the microbial communities, suggesting a direct effect of water on microbes. In wet soils, the structure of the microbial communities was modulated mainly by inoculation; AMF-inoculated D. glomerata soils showed distinct communities. In dry soils, plant type exerted a profound effect on rhizosphere communities; the communities of all three plant types differed, probably due to limitations in the diffusion of nutrients or via reduced root exudation. We concluded that the relative importance of factors shaping rhizosphere microbial communities varies depending on soil moisture regime. Highlights: Microbial communities were studied in relation to water regime, plant species and AMF inoculation In wet soils, the microbial communities of AMF-inoculated D. glomerata plants differed from other communities In dry soils, the microbial communities of D. glomerata and mixtures differed AMF increased bacterial biomass and soil P but decreased nitrate:ammonium ratio.
AB - Different plant species, water regimes and microbes in the rhizosphere might shape rhizosphere microbial communities due to their effects on root exudation patterns and interactions. In this study, we investigated whether rhizosphere microbial communities have distinct structures according to plant type (Festuca pratensis, Dactylis glomerata or a mixture of both species), water regime (dry and wet pots) and inoculation with the arbuscular mycorrhizal fungus Rhizophagus irregularis (AMF). Following a 60-day pot experiment we assessed the rhizosphere microbial population structure via phospholipid fatty acids (PLFAs) and soil processes via the activity of N-acetyl-glucosaminidase (NAG), acid phosphatase and urease, and inorganic nitrogen (N) and phosphorus (P). Higher AMF colonization was recorded in F. pratensis, although its root and shoot biomass was lower than in D. glomerata. Although growth differed between the plant types, this exerted no influence on rhizosphere microbial biomass. Low water content decreased the biomass of all microbial groups, whereas inoculation with AMF decreased the biomass of fungi and increased that of bacteria. For enzyme activities only urease showed a response to treatments. Arbuscular mycorrhizal fungi inoculation increased available P and shifted mineral N content from nitrate to ammonium. The water regime had a dominant effect on the structure of the microbial communities, suggesting a direct effect of water on microbes. In wet soils, the structure of the microbial communities was modulated mainly by inoculation; AMF-inoculated D. glomerata soils showed distinct communities. In dry soils, plant type exerted a profound effect on rhizosphere communities; the communities of all three plant types differed, probably due to limitations in the diffusion of nutrients or via reduced root exudation. We concluded that the relative importance of factors shaping rhizosphere microbial communities varies depending on soil moisture regime. Highlights: Microbial communities were studied in relation to water regime, plant species and AMF inoculation In wet soils, the microbial communities of AMF-inoculated D. glomerata plants differed from other communities In dry soils, the microbial communities of D. glomerata and mixtures differed AMF increased bacterial biomass and soil P but decreased nitrate:ammonium ratio.
KW - above-below ground interactions
KW - enzyme activities
KW - soil nutrients
KW - water context-specific
KW - above–below ground interactions
KW - water context specific
UR - http://www.scopus.com/inward/record.url?scp=85074080740&partnerID=8YFLogxK
U2 - 10.1111/ejss.12882
DO - 10.1111/ejss.12882
M3 - Article
SN - 1351-0754
VL - 71
SP - 265
EP - 278
JO - European Journal of Soil Science
JF - European Journal of Soil Science
IS - 2
ER -