Inside the root microbiome: bacterial root endophytes and plant growth promotion.
Bacterial root endophytes reside in a vast number of plant species as part of their root microbiome, with some being shown to positively influence plant growth. Endophyte community structure (species diversity: richness and relative abundances) within the plant is dynamic and is influenced by abiotic and biotic factors such as soil conditions, biogeography, plant species, microbe-microbe interactions and plant-microbe interactions, both at local and larger scales. Plant-growth-promoting bacterial endophytes (PGPBEs) have been identified, but the predictive success at positively influencing plant growth in field conditions has been limited. Concurrent to the development of modern molecular techniques, the goal of predicting an organism's ability to promote plant growth can perhaps be realized by more thorough examination of endophyte community dynamics. This paper reviews the drivers of endophyte community structure relating to plant growth promotion, the mechanisms of plant growth promotion, and the current and future use of molecular techniques to study these communities.
School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Jonathan R
JR
Gaiero
Crystal A
CA
McCall
Karen A
KA
Thompson
Nicola J
NJ
Day
Anna S
AS
Best
Kari E
KE
Dunfield
D060026:Endophytes / Q000502:physiology*; D064307:Microbiota; D063245:Plant Development; D018517:Plant Roots / Q000382:microbiology*; D010944:Plants / Q000382:microbiology*; D058441:Rhizosphere; D012988:Soil Microbiology; D013559:Symbiosis
endosphere; microbial community; molecular methods; plant-growth-promoting bacteria; plant–microbe interactions; rhizosphere