Applications of the indole-alkaloid gramine modulate the assembly of individual members of the barley rhizosphere microbiota

PeerJ

article

Mauro Maver¹  Carmen Escudero-Martinez¹  James Abbott⁴  Jenny Morris⁵  Pete E. Hedley⁵  Tanja Mimmo²  Davide Bulgarelli¹ 

[1] Plant Sciences, School of Life Sciences, University of Dundee;Faculty of Science and Technology, Free University of Bozen-Bolzano;Competence Centre for Plant Health, Free University of Bozen-Bolzano;Data Analysis Group, School of Life Sciences, University of Dundee;Cell and Molecular Sciences, The James Hutton Institute

关键词: Barley;    Rhizosphere;    Microbiota;    Domestication;    Gramine;   

DOI  :  10.7717/peerj.12498

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Microbial communities proliferating at the root-soil interface, collectively referred to as the rhizosphere microbiota, represent an untapped beneficial resource for plant growth, development and health. Integral to a rational manipulation of the microbiota for sustainable agriculture is the identification of the molecular determinants of these communities. In plants, biosynthesis of allelochemicals is centre stage in defining inter-organismal relationships in the environment. Intriguingly, this process has been moulded by domestication and breeding selection. The indole-alkaloid gramine, whose occurrence in barley (Hordeum vulgare L.) is widespread among wild genotypes but has been counter selected in several modern varieties, is a paradigmatic example of this phenomenon. This prompted us to investigate how exogenous applications of gramine impacted on the rhizosphere microbiota of two, gramine-free, elite barley varieties grown in a reference agricultural soil. High throughput 16S rRNA gene amplicon sequencing revealed that applications of gramine interfere with the proliferation of a subset of soil microbes with a relatively broad phylogenetic assignment. Strikingly, growth of these bacteria appeared to be rescued by barley plants in a genotype- and dosage-independent manner. In parallel, we discovered that host recruitment cues can interfere with the impact of gramine application in a host genotype-dependent manner. Interestingly, this latter effect displayed a bias for members of the phyla Proteobacteria. These initial observations indicate that gramine can act as a determinant of the prokaryotic communities inhabiting the root-soil interface.

【 授权许可】

CC BY