scholarly journals Spatial and temporal expression patterns of lolitrem biosynthetic genes in the Epichloe festucae-perennial ryegrass symbiosis

2007 ◽  
Vol 13 ◽  
pp. 480-480
Author(s):  
K.J. May ◽  
M.K. Bryant ◽  
X. Zhang ◽  
B. Ambrose ◽  
B. Scott
Keyword(s):  
Host Plant ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Expression Patterns ◽  
Temporal Expression ◽  
Intercellular Spaces ◽  
Biosynthetic Genes ◽  
Epichloë Festucae

Epichloë festucae systemically colonises the intercellular spaces of perennial ryegrass (Lolium perenne) aerial tissues forming a mutually beneficial association between the fungus and host plant.

scholarly journals Patterns of Expression of a Lolitrem Biosynthetic Gene in the Epichloë festucae–Perennial Ryegrass Symbiosis

2008 ◽  
Vol 21 (2) ◽  
pp. 188-197 ◽  
Author(s):  
Kimberley J. May ◽  
Michelle K. Bryant ◽  
Xiuwen Zhang ◽  
Barbara Ambrose ◽  
Barry Scott
Keyword(s):  
Gene Expression ◽  
Developmental Stages ◽  
Expression Patterns ◽  
In Planta ◽  
Temporal Expression ◽  
Epichloë Festucae ◽  
Gusa Reporter Gene ◽  
Reporter Gene Analysis ◽  
High Level ◽  
Germinating Seeds

Lolitrem B is synthesized by Epichloë festucae in associations with Pooid grasses. A complex cluster of at least 10 genes (ltm genes) is required for its synthesis. An early step in this pathway is catalyzed by ltmM, a symbiosis-expressed gene. PltmM-gusA reporter gene analysis was used to monitor ltmM gene expression patterns in planta. The minimum promoter length required for high-level gusA expression in infected seedlings is in the range of 480 to 782 bp. gusA was expressed by the endophyte in all infected vegetative plant tissues and in epiphyllous hyphae. Spikelets from reproductive tillers were analyzed at different developmental stages. During pre-anthesis, gusA expression was observed in all infected floral organs except the immature gynoecium. In post-anthesis florets, gene expression occurred almost exclusively in the gynoecium. Expression of gusA by the endophyte was observed in germinating seeds 24 h postimbibition and seedlings older than 6 days postimbibition in hyphae from the mesocotyl to the tip of the emerging first leaf. This work provides a detailed analysis of the spatial and temporal expression patterns of a symbiosis-expressed gene in planta.

scholarly journals Chitin Deacetylases are Required for Epichloë festucae Endophytic Cell Wall Remodelling During Establishment of a Mutualistic Symbiotic Interaction with Lolium perenne

2021 ◽  
Author(s):  
Nazanin Noorifar ◽  
Matthew Savoian ◽  
Arvina Ram ◽  
Yonathan Lukito ◽  
Berit Hassing ◽  
...  
Keyword(s):  
Cell Wall ◽  
Lolium Perenne ◽  
Molecular Probes ◽  
Symbiotic Association ◽  
In Planta ◽  
Intercellular Spaces ◽  
Free Living ◽  
Chitin Deacetylase ◽  
Symbiotic Interaction ◽  
Epichloë Festucae

Epichloë festucae forms a mutualistic symbiotic association with Lolium perenne. This biotrophic fungus systemically colonizes the intercellular spaces of aerial tissues to form an endophytic hyphal network, and also grows as an epiphyte. However, little is known about the cell wall remodelling mechanisms required to avoid host defence and maintain intercalary growth within the host. Here we use a suite of molecular probes to show that the E. festucae cell wall is remodelled by conversion of chitin to chitosan during infection of L. perenne seedlings as the hyphae switch from free-living to endophytic growth. When hyphae transition from endophytic to epiphytic growth the cell wall is remodelled from predominantly chitosan to chitin. This conversion from chitin to chitosan is catalysed by chitin deacetylase. The genome of E. festucae encodes three putative chitin deacetylases, two of which (cdaA and cdaB) are expressed in planta. Deletion of either of these genes results in disruption of fungal intercalary growth in the intercellular spaces of plants infected with these mutants. These results establish that these two genes are required for maintenance of the mutualistic symbiotic interaction between E. festucae and L. perenne.

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

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.

scholarly journals The Fungal Cell-Wall Integrity MAPK Cascade Is Crucial for Hyphal Network Formation and Maintenance of Restrictive Growth of Epichloë festucae in Symbiosis With Lolium perenne

2015 ◽  
Vol 28 (1) ◽  
pp. 69-85 ◽  
Author(s):  
Yvonne Becker ◽  
Carla J. Eaton ◽  
Emma Brasell ◽  
Kimberley J. May ◽  
Matthias Becker ◽  
...  
Keyword(s):  
Cell Wall ◽  
Lolium Perenne ◽  
Network Formation ◽  
Mapk Pathway ◽  
Cell Wall Integrity ◽  
Mitogen Activated Protein Kinase ◽  
Vascular Bundles ◽  
Intercellular Spaces ◽  
Symbiotic Interaction ◽  
Epichloë Festucae

Epichloë festucae is a mutualistic symbiont that systemically colonizes the intercellular spaces of Lolium perenne leaves to form a highly structured and interconnected hyphal network. In an Agrobacterium tumefaciens T-DNA forward genetic screen, we identified a mutant TM1066 that had a severe host interaction phenotype, causing stunting and premature senescence of the host. Molecular analysis revealed that the mutation responsible for this phenotype was in the cell-wall integrity (CWI) mitogen-activated protein kinase kinase (MAPKK), mkkA. Mutants generated by targeted deletion of the mkkA or the downstream mpkA kinase recapitulated the phenotypes observed for TM1066. Both mutants were defective in hyphal cell–cell fusion, formed intrahyphal hyphae, had enhanced conidiation, and showed microcyclic conidiation. Transmission electron microscopy and confocal microscopy analysis of leaf tissue showed that mutant hyphae were more abundant than the wild type in the intercellular spaces and colonized the vascular bundles. Hyphal branches failed to fuse but, instead, grew past one another to form bundles of convoluted hyphae. Mutant hyphae showed increased fluorescence with AF488-WGA, indicative of increased accessibility of chitin, a hypothesis supported by changes in the cell-wall ultrastructure. These results show that the CWI MAPK pathway is a key signaling pathway for controlling the mutualistic symbiotic interaction between E. festucae and L. perenne.

scholarly journals Identification and Characterization of Perennial Ryegrass (Lolium perenne) Vernalization Genes

2021 ◽  
Vol 12 ◽  
Author(s):  
Rowan Herridge ◽  
Samarth ◽  
Lynette Brownfield ◽  
Richard Macknight
Keyword(s):  
Flowering Time ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Energy Content ◽  
Brachypodium Distachyon ◽  
Expression Patterns ◽  
Metabolizable Energy ◽  
Grass Species ◽  
Species Variation ◽  
Vernalization Response

Perennial ryegrass (Lolium perenne) is a temperate grass species commonly used as pasture for livestock. Flowering (heading) of ryegrass impacts metabolizable energy content and seed yield, therefore this trait is important for both farmers and seed producers. In related grass species, the VRN genes (VRN1-3) have been largely implicated in the determination of vernalization response and are responsible for much of the intra-species variation in this trait. Many other important flowering-time regulators have been cataloged in the model grass Brachypodium distachyon; however, in several cases, such as VRN2, their ryegrass homologs have not been well-characterized. Here, ryegrass homologs of important flowering time genes from B. distachyon were identified through available synteny data and sequence similarity. Phylogenetic analysis of VRN3/FT-like and VRN2-like genes was performed to elucidate these families further. The expression patterns of these genes were assessed during vernalization. This confirmed the key roles played by LpVRN1 and LpFT3 in the promotion of flowering. Furthermore, two orthologs of VRN2 identified here, as well as an ortholog of CO9, were expressed prior to vernalization, and were repressed in flowering plants, suggesting a role in floral repression. Significant variability in expression of these flowering pathway genes in diverse genotypes was detected and may underlie variation in flowering time and vernalization response.

Effect of bacterial fertilizers on the properties of a pseudomyceliar chernozem soil and on the biomass of perennial ryegrass (Lolium perenne L.)

2011 ◽  
Vol 60 (1) ◽  
pp. 219-232 ◽  
Author(s):  
Anita Jakab ◽  
János Kátai ◽  
Magdolna Tállai ◽  
Andrea Balláné Kovács
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Chernozem Soil ◽  
Lolium Perenne L

A tenyészedényes kísérletünket a DE AGTC MÉK Agrokémiai és Talajtani Intézet tenyészházában állítottuk be 2010. május 27-én. A kísérletben Debrecen-Látókép környékéről származó mészlepedékes csernozjom vályogtalajt alkalmaztunk, amely az alábbi jellemzőkkel rendelkezett: KA: 37,5; leiszapolható rész: 51%; pH(KCl): 5,5; pH(H2O): 6,6; Hu%: 2,8; AL-P2O5: 140 mg·kg-1; AL-K2O: 316,3 mg·kg-1. Az adatok alapján a kísérleti talaj gyengén savanyú, vályog kötöttségű, közepes nitrogén- és foszfor-, valamint jó kálium-ellátottsággal rendelkezett. A kísérletben kontroll-, műtrágya-, valamint szalmakezelést alkalmaztunk, melyeket bizonyos kombinációkban három különböző baktériumkészítménnyel (Bactofil A, EM-1, Microbion UNC) egészítettünk ki. A kísérletet három ismétlésben véletlenblokk elrendezésben állítottuk be. A tesztnövény angolperje (Lolium perenneL.) volt. A kísérlet kezdetétől számított 8. héten a talaj-, valamint a növényminták begyűjtésére került sor. Meghatároztuk a növényminták száraztömegét, a növény foszfor- és káliumtartalmát, valamint a talajminták nitrát-, valamint AL-oldható foszfor- és káliumtartalmát. Eredményeink alapján főbb megállapításaink a következők: – Az angolperje száraztömegét a műtrágyakezelés szignifikánsan növelte. A hatás a tápelem-ellátottság javulásával magyarázható. – A növény foszforkoncentrációja a műtrágyázás következtében csökkent, amelyet a hígulási effektussal magyarázhatunk. – A növény káliumkoncentrációját a műtrágya-, valamint a műtrágya+baktériumtrágya kezelések szignifikánsan serkentették. – A talaj nitráttartalma szignifikánsan növekedett a műtrágyakezelés kivételével minden kezelésben. – A talaj AL-P2O5-tartalma az NPK-műtrágyázás és az EM-1 kezelés következtében statisztikailag igazolható mértékben megnövekedett, míg az AL-K2O-tartalom kizárólag a szalmakezelés hatására nőtt. A baktériumkészítmények önmagukban alkalmazva általában nem eredményeztek jelentős változást a vizsgált paraméterekben, azonban a készítmények szerves/ásványi anyagokkal kombinált adagolása esetében különböző mértékben befolyásolták a vizsgált mutatókat.

The effect of biological additives on the composition and nutritive value of silage

1990 ◽  
Vol 1990 ◽  
pp. 139-139
Author(s):  
M Gonzalez Yanez ◽  
R Mcginn ◽  
D H Anderson ◽  
A R Henderson ◽  
P Phillips
Keyword(s):  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Nutritive Value ◽  
Enzyme System ◽  
Lolium Perenne L ◽  
Grass Silage ◽  
Forage Harvester

It Is claimed that the use of the correct enzyme system as an additive on grass silage will satisfactorily control the fermentation and reduce the cell-wall fibre content, thus preserving the nutrients In the silage and aiding their utilisation by the animal (Henderson and McDonald, 1977; Huhtanen et al, 1985; Raurama et al, 1987; Chamberlain and Robertson, 1989; Gordon, 1989;).The aim of the present experiment was to assess the effect of biological additives, enzymes or a combination of enzymes with an Inoculum of lactic acid bacteria, on the composition of silage and on its nutritive value when offered to store lambs as the sole constituent of their diet.On 1st June 1988, first cut perennial ryegrass (Lolium perenne L) at pre-ear emergence was ensiled direct cut untreated (U), treated with a commercial enzyme (E) or with a commercial inoculum of lactic acid bacteria with enzymes (I) in 6t capacity bunker silos. The grass was cut with a mower and lifted with a New Holland precision chop forage harvester. The additives were pumped onto the grass using a dribble bar sited over the pick-up drum.

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