An Assessment of the Lolium perenne (Perennial Ryegrass) Seedborne Microbiome across Cultivars, Time, and Biogeography: Implications for Microbiome Breeding

Research into the bacterial component of the seed microbiome has been intensifying, with the aim of understanding its structure and potential for exploitation. We previously studied the intergenerational seed microbiome of one cultivar of perennial ryegrass with and without one strain of the commercially deployed fungal endophyte Epichloë festucae var. lolii. The work described here expands on our previous study by exploring the bacterial seed microbiome of different commercial cultivar/Epichloë festucae var. lolii combinations in collections of single seeds from the harvest year 2016. In this dataset, a cultivar effect could be seen between the seed microbiomes from cultivars Alto and Trojan. The bacterial component of the seed microbiome from pooled seeds from a single cultivar/E. festucae var. lolii combination harvested from 13 seed production farms around Canterbury in the year 2018 was also studied. This dataset allows the effect of different production locations on the bacterial seed microbiome to be examined. By comparing the two sets of data, bacteria from the genera Pantoea, Pseudomonas, Duganella, Massilia, and an unknown Enterobacteriaceae were observed to be in common. This core bacterial microbiome was stable over time but could be affected by supplemental taxa derived from the growth environment of the parental plant; differing microbiomes were seen between different seed production farms. By comparison to a collection of bacterial isolates, we demonstrated that many of the members of the core microbiome were culturable. This allows for the possibility of exploiting these microbes in the future.

Download Full-text

Profiling the Lolium perenne Microbiome: From Seed to Seed

Phytobiomes Journal ◽

10.1094/pbiomes-03-20-0026-r ◽

2020 ◽

Vol 4 (3) ◽

pp. 281-289 ◽

Cited By ~ 1

Author(s):

Ian Tannenbaum ◽

Jatinder Kaur ◽

Ross Mann ◽

Timothy Sawbridge ◽

Brendan Rodoni ◽

...

Keyword(s):

Lolium Perenne ◽

Perennial Ryegrass ◽

Grass Species ◽

Growth Media ◽

Dairy Farmers ◽

Pasture Grass ◽

Core Microbiome ◽

Operational Taxonomic Units ◽

Bacterial Microbiome ◽

Seed Transmissibility

Lolium perenne (perennial ryegrass) is a common temperate pasture grass species and is favored 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 ribosomal RNA gene was used to examine the bacterial microbiome of perennial ryegrass (Alto) seed (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 class Gammaproteobacteria. The mature plant microbiomes were far more diverse, comprising up to 37 classes inclusive of Gammaproteobacteria. Different growth media yielded different microbiome profiles in mature plants. The G2 microbiome, similar to the G1 microbiome, was dominated by Gammaproteobacteria as the primary constituent, with additional supplementation from class 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 bacterial microbiomes and has identified some operational taxonomic units of potential commercial significance due to their seed transmissibility, and their roles are currently being explored.

Download Full-text

Effects of the Fungal Endophyte Epichloë festucae var. lolii on Growth and Physiological Responses of Perennial Ryegrass cv. Fairway to Combined Drought and Pathogen Stresses

Microorganisms ◽

10.3390/microorganisms8121917 ◽

2020 ◽

Vol 8 (12) ◽

pp. 1917

Author(s):

Fang Li ◽

Tingyu Duan ◽

Yanzhong Li

Keyword(s):

Plant Growth ◽

Soil Water ◽

Perennial Ryegrass ◽

Disease Incidence ◽

Bipolaris Sorokiniana ◽

P Uptake ◽

Fungal Endophyte ◽

Photosynthetic Parameters ◽

Epichloë Festucae ◽

Combined Stresses

Perennial ryegrass (Lolium perenne) is widely cultivated around the world for turf and forage. However, the plant is highly susceptible to disease and is sensitive to drought. The present study aims to determine the effect of the fungal endophyte Epichloë festucae var. lolii of perennial ryegrass on the combined stresses of drought and disease caused by Bipolaris sorokiniana in the greenhouse. In the experiment, plants infected (E+) or not infected (E−) with the fungal endophyte were inoculated with Bipolaris sorokiniana and put under different soil water regimes (30%, 50%, and 70%). The control treatment consisted of E+ and E− plants not inoculated with B. sorokiniana. Plant growth, phosphorus (P) uptake, photosynthetic parameters, and other physiological indices were evaluated two weeks after pathogen infection. The fungal endophyte in E+ plants increased P uptake, plant growth, and photosynthetic parameters but decreased the malondialdehyde concentration, proline content, and disease incidence of perennial ryegrass (p < 0.05). E+ plants had the lowest disease incidence at 70% soil water (p < 0.05). The study demonstrates that the fungal endophyte E. festucae var. lolii is beneficial for plant growth and stress tolerance in perennial ryegrass exposed to the combined stresses of drought and B. sorokiniana.

Download Full-text

The fungal endophyte Epichloë festucae var. lolii plays a limited role in mediating crown rust severity in perennial ryegrass

Crop Science ◽

10.1002/csc2.20095 ◽

2020 ◽

Vol 60 (2) ◽

pp. 1090-1104

Author(s):

Garett C. Heineck ◽

Yinjie Qiu ◽

Nancy J. Ehlke ◽

Eric Watkins

Keyword(s):

Perennial Ryegrass ◽

Fungal Endophyte ◽

Crown Rust ◽

Epichloë Festucae ◽

Limited Role ◽

Rust Severity

Download Full-text

Examining the Impacts of CO2 Concentration and Genetic Compatibility on Perennial Ryegrass—Epichloë festucae var lolii Interactions

Journal of Fungi ◽

10.3390/jof6040360 ◽

2020 ◽

Vol 6 (4) ◽

pp. 360

Author(s):

Jennifer Geddes-McAlister ◽

Arjun Sukumaran ◽

Aurora Patchett ◽

Heather A. Hager ◽

Jenna C. M. Dale ◽

...

Keyword(s):

Lolium Perenne ◽

Perennial Ryegrass ◽

Carbon Fixation ◽

Plant Biomass ◽

Co2 Concentration ◽

Fungal Endophyte ◽

Genetic Profile ◽

Genetic Incompatibility ◽

Data Set ◽

Epichloë Festucae

Perennial ryegrass (Lolium perenne) is the most cultivated cool-season grass worldwide with crucial roles in carbon fixation, turfgrass applications, and fodder for livestock. Lolium perenne forms a mutualism with the strictly vertically transmitted fungal endophyte, Epichloë festucae var lolii. The fungus produces alkaloids that protect the grass from herbivory, as well as conferring protection from drought and nutrient stress. The rising concentration of atmospheric CO2, a proximate cause of climatic change, is known to have many direct and indirect effects on plant growth. There is keen interest in how the nature of this plant–fungal interaction will change with climate change. Lolium perenne is an obligately outcrossing species, meaning that the genetic profile of the host is constantly being reshuffled. Meanwhile, the fungus is asexual implying both a relatively constant genetic profile and the potential for incompatible grass–fungus pairings. In this study, we used a single cultivar, “Alto”, of L. perenne. Each plant was infected with one of four strains of the endophyte: AR1, AR37, NEA2, and Lp19 (the “common strain”). We outcrossed the Alto mothers with pollen from a number of individuals from different ryegrass cultivars to create more genetic diversity in the hosts. We collected seed such that we had replicate maternal half-sib families. Seed from each family was randomly allocated into the two levels of the CO2 treatment, 400 and 800 ppm. Elevated CO2 resulted in an c. 18% increase in plant biomass. AR37 produced higher fungal concentrations than other strains; NEA2 produced the lowest fungal concentrations. We did not find evidence of genetic incompatibility between the host plants and the fungal strains. We conducted untargeted metabolomics and quantitative proteomics to investigate the grass-fungus interactions between and within family and treatment groups. We identified a number of changes in both the proteome and metabalome. Taken together, our data set provides new understanding into the intricacy of the interaction between endophyte and host from multiple molecular levels and suggests opportunity to promote plant robustness and survivability in rising CO2 environmental conditions through application of bioprotective epichloid strains.

Download Full-text

Fungal Endophyte Production of Reactive Oxygen Species is Critical for Maintaining the Mutualistic Symbiotic Interaction BetweenEpichloë festucaeand Perennial Ryegrass

Plant Signaling & Behavior ◽

10.4161/psb.2.3.3725 ◽

2007 ◽

Vol 2 (3) ◽

pp. 171-173 ◽

Cited By ~ 7

Author(s):

Barry Scott ◽

Daigo Takemoto ◽

Aiko Tanaka

Keyword(s):

Reactive Oxygen Species ◽

Perennial Ryegrass ◽

Reactive Oxygen ◽

Fungal Endophyte ◽

Oxygen Species ◽

Symbiotic Interaction

Download Full-text

NUCLEUS SEED MULTIPLICATION

NZGA: Research and Practice Series ◽

10.33584/rps.5.1998.3338 ◽

1990 ◽

Vol 5 ◽

pp. 30-31

Author(s):

E. Kevern

Keyword(s):

Seed Production ◽

Perennial Ryegrass ◽

Selection Of

The multiplic,ation of Nucleus Seed to produce Breeders' Seed of any of the Grasslands Division cultivars not covered by Head Licensees is handled by the Grasslands Division Seed Production Specialist. The procedure for the selection of increase areas is as follows. The Region: Wherever possible, cultivars are kept to districts that produce that type of cultivar already. As an example, 'Grasslands Ruanui' perennial ryegrass is grown at Waitohi in South Canterbury. This helps eliminate chance of crosspollination, provides better isolation, and reduces the likelihood of disagreements between

Download Full-text

Assessment of gene flow using tetraploid genotypes of perennial ryegrass (Lolium perenne L.)

Australian Journal of Agricultural Research ◽

10.1071/ar03156 ◽

2004 ◽

Vol 55 (4) ◽

pp. 389 ◽

Cited By ~ 15

Author(s):

K. V. Cunliffe ◽

A. C. Vecchies ◽

E. S. Jones ◽

G. A. Kearney ◽

J. W. Forster ◽

...

Keyword(s):

Gene Flow ◽

Seed Production ◽

Lolium Perenne ◽

Perennial Ryegrass ◽

Grass Species ◽

Numerical Representation ◽

Pasture Grass ◽

Important Species ◽

Lolium Perenne L ◽

Total Seed

Ryegrass species are among the most important species in sown pastures, turf settings, and weed populations worldwide. Perennial ryegrass (Lolium perenne L.) is an outcrossing, wind-pollinated grass. Recent research has demonstrated the feasibility of developing transgenic perennial ryegrass varieties. In order to model the consequences of gene flow from transgenic grass genotypes in a field situation, the model non-transgenic trait of fertility among autotetraploid genotypes was chosen. Gene flow over distance and direction from a donor plot to surrounding sexually compatible recipient plants was studied. Reproductive isolation was achieved through the fertility barrier that arises between tetraploid and diploid ryegrass genotypes, despite the presence of diploid plants in a meadow situation. Fertility was used as an indication of effective gene flow over distance and direction. Measures of the fertility of recipient plants included total seed production (TSP), floret site utilisation (FSU), and relative fertility of recipient plants as a percentage of those within the donor plot (RF%). A leptokurtic distribution for gene flow was identified, with differences in the rate of decline over distance depending on direction. Simple sequence repeat (SSR) polymorphism was used to identify the paternity of progeny plants. The proportional representation of parents among the progeny was not significantly different from that expected due to the numerical representation of the different donor parent genotypes. The results of this research will have important implications for risk analysis prior to the field release of transgenic ryegrasses, fescues, and other pasture grass species, and for seed production in terms of cultivar purity and optimum isolation distance.

Download Full-text