Profiling the Lolium perenne Microbiome: From Seed to Seed

Abstract

<jats:p> Lolium perenne (perennial ryegrass) is a common temperate pasture grass species and is favoured by dairy farmers. Commercially, the known association with the mutualistic endophytic fungus Epichloë festucae subsp. lolii is used to enhance insect resistance of host plants. Knowledge of other members of the microbiome and their functions are limited. Sequencing of the V4 region of the 16S rRNA gene was used to examine the bacterial microbiome of perennial ryegrass (cv. Alto) seeds (Generation 1, G1), subsequent mature plants grown in soil and sand, and seed (Generation 2, G2) from crosses of these mature plants. The G1 microbiome was dominated by the Gammaproteobacteria. The mature plant microbiomes were far more diverse, comprising of up to 37 Classes inclusive of Gammaproteobacteria. Different growth media yielded different microbiome profiles in mature plants. The G2 microbiome, as G1, was dominated by Gammaproteobacteria with additional supplementation of Bacilli. This suggests the continuation of a core microbiome which persists from seed, through plant maturation, to seed. This study sheds new light on the hereditability of perennial ryegrass microbiomes and has identified some OTUs of potential commercial significance due to their seed transmissibility and their roles are currently being explored. </jats:p>

Profiling, isolation and characterisation of beneficial microbes from the seed microbiomes of drought tolerant wheat

“…Seeds harbor the initial inoculum of microbes, playing a vital role in the transmission of microbial resources between plant generations 21 . As the initial colonisers of plant tissue, the seed microbiome is believed to shape the overall composition of the plant microbiome and therefore have a competitive advantage over microbes recruited from soil and root 22 , 23 . It is postulated that the seed microbiome evolves as a result of host selection for traits that complement the plant genome 19 , 24 .…”

Drought Tolerant Wheat Varieties Enrich Seed Microbiomes For Beneficial Microbes Under Drought Conditions

“…Seeds harbor the initial inoculum of microbes, playing a vital role in the transmission of microbial resources between plant generations [20]. As the initial colonisers of plant tissue, the seed microbiome is believed to shape the overall composition of the plant microbiome and therefore have a competitive advantage over microbes recruited from soil and root [21,22]. A comparatively limited number of bacterial genera have been detected in seed microbiomes compared to other plant microbiomes, such as root microbiome [23].…”

Novel Xanthomonas Species From the Perennial Ryegrass Seed Microbiome – Assessing the Bioprotection Activity of Non-pathogenic Relatives of Pathogens

“…Tissue maceration, serial dilutions and bacterial isolations were prepared as above. All isolated bacterial strains were taxonomically classified using matrix assisted laser desorption ionization time-of-flight mass spectrometry (Bruker ultrafleXtreme MALDI-TOF/TOF MS and Biotyper System) ( Tannenbaum et al, 2020 ), and stored in nutrient broth with 15% glycerol (v/v) at −80°C.…”

“…To gain insight into the broader microbiome of pasture grasses, we have profiled the microbiome of perennial ryegrass ( Lolium perenne L. cv. Alto) and isolated bacterial strains ( Tannenbaum et al, 2020 ), which were assessed for their beneficial activities (e.g., bioprotection). Three closely related strains (strain GW, seed-associated; strain SS and SI, mature-plant associated) exhibited excellent bioprotection activities against phytopathogens ( in vitro and in planta ).…”