Lolitrems are a structurally diverse group of indole-diterpene mycotoxins synthesized by Epichloë/Neotyphodium endophytes in association with Pooid grasses. Using suppression subtractive hybridization combined with chromosome walking, two clusters of genes for lolitrem biosynthesis were isolated from Neotyphodium lolii, a mutualistic endophyte of perennial ryegrass. The first cluster contains five genes, ltmP, ltmQ, ltmF, ltmC, and ltmB, four of which appear to be orthologues of functionally characterized genes from Penicillium paxilli. The second cluster contains two genes, ltmE and ltmJ, that appear to be unique to lolitrem biosynthesis. The two clusters are separated by a 16 kb AT-rich sequence that includes two imperfect direct repeats. A previously isolated ltm cluster composed of ltmG, ltmM, and ltmK, is linked to these two new clusters by 35 kb of AT-rich retrotransposon relic sequence. All 10 genes at this complex LTM locus were highly expressed in planta but expression was very low or undetectable in mycelia. ltmM and ltmC were shown to be functional orthologues of P. paxilli paxM and paxC, respectively. This work provides a genetic foundation for elucidating the metabolic grid responsible for the diversity of indole-diterpenes synthesized by N. lolii.
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http://dx.doi.org/10.1016/j.fgb.2006.04.004 | DOI Listing |
N Z Vet J
July 2017
e 153 Evans Street, Dunedin 9010 , New Zealand.
Ryegrass staggers (RGS) is a metabolic disease of herbivores, caused by the ingestion of perennial ryegrass (Lolium perenne L.) containing a fungal endophyte (Neotyphodium lolii) which produces a tremorgenic toxin, lolitrem B. RGS has a major economic impact for agriculture in New Zealand as well as internationally.
View Article and Find Full Text PDFPLoS One
January 2016
Department of Molecular Phytopathology, University of Technology and Life Sciences, Bydgoszcz, Poland.
Endophytic fungi live their whole life within host tissues usually without any visible symptoms. Their vertical transmission (seed-plant-seed) has been well described and documented. However, horizontal transmission (plant-plant) needs more clarification.
View Article and Find Full Text PDFJ Appl Microbiol
May 2015
Center of Biotechnology and Microbiology, University of Peshawar, Khyber Pakhtunkhwa, Pakistan; Laboratoire de Génie Chimique, INPT-UPS, Université de Toulouse, Castanet-Tolosan Cedex, France.
Aims: To provide an efficient technique for monitoring the off-flavoured fungal compound geosmin.
Methods And Results: Geosmin-associated gpe1 gene of Penicillium expansum displayed ≥99% similarity to cytochrome P450 gene of geosmin-producing P. restrictum, but ≤40% similarities to geosmin biosynthesis, non-cytochromic gene of Streptomyces avermitilis and cytochrome P450 genes of non-geosmin-producing Neotyphodium lolii, Phoma betae and P.
Am J Bot
December 2014
Center for Environmental Science, College of Staten Island, City University of New York, Staten Island, New York 10314.
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Premise Of The Study: Cool-season grasses infected by endophytic fungal symbionts sometimes show improved tolerance of herbivory and abiotic stresses, but the potential effects of endophytes on host competitive ability are unclear. This study examined intraspecific competition among variable genotypes of Lolium perenne with and without the endophyte Epichloë festucae var. lolii (Clavicipitaceae, Ascomycota) to assess the effect of infection on competitive outcomes.
Ir Vet J
October 2014
Centre for Veterinary Epidemiology and Risk Analysis (CVERA), Veterinary Sciences Centre, University College Dublin, Belfield, Dublin 4, Ireland.
Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as 'ergot alkaloid intoxication'. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites.
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