Plant lignin content altered by soil microbial community

• Published in: The New phytologist 2015-04, Vol.206 (1), p.166-174
• Main Authors: Bennett, Alison E, Grussu, Dominic, Kam, Jason, Caul, Sandra, Halpin, Claire
• Format: Article
• Language: English
• Subjects: arbuscular mycorrhizal (AM) fungi; barley; barley (Hordeum vulgare); biogeochemical cycles; Biomass; Cultivars; dark septate endophyte lignin; Defensive behavior; Ecological studies; Fungi; genotype; Genotypes; Hordeum - genetics; Hordeum - metabolism; Hordeum - microbiology; Hordeum vulgare; Lignin; Lignin - analysis; Lignin - metabolism; Microbial activity; microbiome; Microbiomes; Microorganisms; mutants; Mutation; Mycorrhizae - physiology; Nutrient cycles; plant defense; Plant diversity; plant response; Plant Roots - genetics; Plant Roots - metabolism; Plant Roots - microbiology; Plant Shoots - genetics; Plant Shoots - metabolism; Plant Shoots - microbiology; rob1; roots; Shoots; Soil; soil ecology; soil microbial community; Soil Microbiology; Soil microorganisms; Soils
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.13171

Questions have been raised in various fields of research about the consequences of plants with modified lignin production. As a result of their roles in nutrient cycling and plant diversity, plant–soil interactions should be a major focus of ecological studies on lignin‐modified plants. However, most studies have been decomposition studies conducted in a single soil or in sterile soil. Thus, we understand little about plant–soil interactions in living lignin‐modified plants. In lignin mutants of three different barley (Hordeum vulgare) cultivars and their corresponding wild‐types associated with three different soil microbial communities, we asked: do plant–soil microbiome interactions influence the lignin content of plants?; does a mutation in lignin production alter the outcome of plant–soil microbiome interactions?; does the outcome of plant–soil microbiome interactions depend on host genotype or the presence of a mutation altering lignin production? In roots, the soil community explained 6% of the variation in lignin content, but, in shoots, the soil community explained 21% of the variation in lignin content and was the only factor influencing lignin content. Neither genotype nor mutations in lignin production explained associations with fungi. Lignin content changes in response to a plant's soil microbial community, and may be a defensive response to particular components of the soil community.