Investigation and Expression of the Secoisolariciresinol Dehydrogenase Gene Involved in Podophyllotoxin Biosynthesis

Arneaud, Sonja L. B.; Porter, John R.

doi:10.1007/s12033-015-9888-8

Cited by 10 publications

(14 citation statements)

References 35 publications

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“…The entangled relationship between Mollisia and Phialocephala ( Mollisiaceae , Helotiales ), a genus comprising important root and leaf endophytes and known mostly by asexual morphs, suggests that the ecology of Mollisia species is more complex than previously assumed ( Day et al., 2012 , Tanney et al., 2016a ). Phialocephala species are saprotrophs, plant mutualists, potential plant health promoters, producers of industrially significant secondary metabolites, and infrequent causal agents of plant diseases ( Frasz et al., 2014 , Arneaud and Porter, 2015 , Wong et al., 2015 ). The most well-studied Phialocephala species belong to the P. fortinii sensu lato ( s.l.…”

Section: Introductionmentioning

confidence: 99%

Mollisiaceae: An overlooked lineage of diverse endophytes

Tanney

Seifert

2020

Studies in Mycology

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Mollisia is a taxonomically neglected discomycete genus ( Helotiales, Leotiomycetes ) of commonly encountered saprotrophs on decaying plant tissues throughout temperate regions. The combination of indistinct morphological characters, more than 700 names in the literature, and lack of reference DNA sequences presents a major challenge when working with Mollisia . Unidentified endophytes, including strains that produced antifungal or antiinsectan secondary metabolites, were isolated from conifer needles in New Brunswick and placed with uncertainty in Phialocephala and Mollisia , necessitating a more comprehensive treatment of these genera. In this study, morphology and multigene phylogenetic analyses were used to explore the taxonomy of Mollisiaceae , including Mollisia , Phialocephala , and related genera, using new field collections, herbarium specimens, and accessioned cultures and sequences. The phylogeny of Mollisiaceae was reconstructed and compared using the nuc internal transcribed spacer rDNA (ITS) barcode and partial sequences of the 28S nuc rDNA (LSU) gene, largest subunit of RNA polymerase II ( RPB1 ), DNA topoisomerase I ( TOP1 ), and the hypothetical protein Lipin/Ned1/Smp2 ( LNS2 ). The results show that endophytism is common throughout the Mollisiaceae lineage in a diverse range of hosts but is infrequently attributed to Mollisia because of a paucity of reference sequences. Generic boundaries within Mollisiaceae are poorly resolved and based on phylogenetic evidence the family included species placed in Acephala , Acidomelania , Barrenia , Bispora , Cheirospora , Cystodendron , Fuscosclera , Hysteronaevia, Loramyces, Mollisia, Neopyrenopeziza , Obtectodiscus, Ombrophila, Patellariopsis , Phialocephala , Pulvinata , Tapesia (= Mollisia ), and Trimmatostroma. Taxonomic novelties included the description of five novel Mollisia species and five novel Phialocephala species and the synonymy of Fuscosclera with Phialocephala , Acidomelania with Mollisia , and Loramycetaceae with Mollisiaceae .

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Section: Introductionmentioning

confidence: 99%

Mollisiaceae: An overlooked lineage of diverse endophytes

Tanney

Seifert

2020

Studies in Mycology

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“…As found with the other plant-derived compounds discussed earlier, these fermentations yielded low levels in the range from 0.5 µg • L −1 to 189 µg • L −1 . However, concentrations of podophyllotoxin could sometimes increase between subculturings, suggesting the metabolite is not present due to carryover from the plant [85]. In addition, secoisolariciresinol dehydrogenase (SD) genes in the proposed podophyllotoxin biosynthetic pathway have been found in both P. peltatum and the endophyte Phialocephala podophylli (strain PPE7), with the genes characterized in vitro, the first time that the SD gene was characterized in the fungal kingdom [85].…”

Section: Podophyllotoxinmentioning

confidence: 99%

“…However, concentrations of podophyllotoxin could sometimes increase between subculturings, suggesting the metabolite is not present due to carryover from the plant [85]. In addition, secoisolariciresinol dehydrogenase (SD) genes in the proposed podophyllotoxin biosynthetic pathway have been found in both P. peltatum and the endophyte Phialocephala podophylli (strain PPE7), with the genes characterized in vitro, the first time that the SD gene was characterized in the fungal kingdom [85]. Optimization of production of podophyllotoxin requires more studies on the heterologous expression of genes in this biosynthetic pathway, and the effects of fermentation conditions will hopefully provide insight into metabolic bottlenecks and chemical signals, leading to improved endophytic production of podophyllotoxin [85].…”

Section: Podophyllotoxinmentioning

confidence: 99%

Plant Endophytes and Epiphytes: Burgeoning Sources of Known and “Unknown” Cytotoxic and Antibiotic Agents?

Newman¹,

Cragg²

2020

Planta Med

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In the last 20 or so years, the influence of endophytes and, quite recently, epiphytes of plants upon the compounds found in those plants, which were usually assumed to be phytochemicals produced by the plant for a variety of reasons, often as a defense against predators, is becoming more evident, in particular in the case of antitumor agents originally isolated from plant sources, though antibiotic agents might also be found, particularly from epiphytes. In this review, we started with the first report in 1993 of a taxol-producing endophyte and then expanded the compounds discussed to include camptothecin, the vinca alkaloids, podophyllotoxin, and homoharringtonine from endophytic microbes and then the realization that maytansine is not a plant secondary metabolite at all, and that even such a well-studied plant such as Arabidopsis thaliana has a vast repertoire of potential bioactive agents in its leaf epiphytic bacteria. We have taken data from a variety of sources, including a reasonable history of these discoveries that were not given in recent papers by us, nor in other papers covering this topic. The sources included the Scopus database, but we also performed other searches using bibliographic tools, thus, the majority of the papers referenced are the originals, though we note some very recent papers that have built on previous results. We concluded with a discussion of the more modern techniques that can be utilized to “persuade” endophytes and epiphytes to switch on silent biosynthetic pathways and how current analytical techniques may aid in evaluating such programs. We also comment at times on some findings, particularly in the case of homoharringtonine, where there are repetitious data reports differing by a few years claiming the same endophyte as the producer.

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“…Two strains initially reported as Phialocephala fortinii isolated from rhizomes of Podophyllum peltatum produce podophyllotoxin, a lignan well-studied for its antiviral and antineoplastic properties (Eyberger et al 2006). The podophyllotoxin-producing strain PPE7 was referred to as Phialocephala podophylli but awaits formal description (Arneaud and Porter 2015). A Phialocephala cf.…”

Section: Endophytism Throughout Mollisiaceaementioning

confidence: 99%

“…Phialocephala species may be plant mutualists, potential biocontrol agents, producers of industrially-significant secondary metabolites, or causal agents of important plant diseases (Frasz et al 2014, Arneaud and Porter 2015, Wong et al 2015. Some studies have also reported Mollisia as endophytes of leaves and twigs in diverse host plants (Sieber 1989, Barklund and Kowalski 1996, Shamoun and Sieber 2000, Kowalski and Andruch 2012.…”

Section: Introductionmentioning

confidence: 99%

A Taxonomic and Phylogenetic Investigation of Conifer Endophytes of Eastern Canada

Tanney¹

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Research interest in endophytic fungi has increased substantially, yet is the current research paradigm capable of addressing fundamental taxonomic questions?More than half of the ca. 30,000 endophyte sequences accessioned into GenBank are unidentified to the family rank and this disparity grows every year. The problems with identifying endophytes are a lack of taxonomically informative morphological characters in vitro and a paucity of relevant DNA reference sequences. A study involving ca. 2,600Picea endophyte cultures from the Acadian Forest Region in Eastern Canada sought to address these taxonomic issues with a combined approach involving molecular methods, classical taxonomy, and field work. It was hypothesized that foliar endophytes have complex life histories involving saprotrophic reproductive stages associated with the host foliage, alternative host substrates, or alternate hosts. Based on inferences from phylogenetic data, new field collections or herbarium specimens were sought to connect unidentifiable endophytes with identifiable material. Approximately 40 endophytes were connected with identifiable material, which resulted in the description of four novel genera and 21 novel species and substantial progress in endophyte taxonomy. Endophytes were connected with saprotrophs and exhibited reproductive stages on non-foliar tissues or different hosts. These results provide support for the foraging ascomycete hypothesis, postulating that for some fungi endophytism is a secondary life history strategy that facilitates persistence and dispersal in the absence of a primary host. This thesis provides an alternate approach to identifying endophytes by considering the whole fungus interacting within its natural habitat.iii Acknowledgements I would first like to thank my supervisor Dr. Keith A. Seifert for providing me with the freedom and support to conduct the research presented in this thesis as well as many other side projects and curiosities. Keith generously provided many opportunities to travel to domestic and international conferences, which made me more aware of the directions of global mycological research and provided the opportunity to meet many of the great mycological heroes and their contemporaries. Our discussions over the last five years have contributed to my development as a more well-rounded and openminded researcher, professional, and person; his honesty and integrity are qualities that all professionals should aspire to have. I am indebted to Keith for the knowledge, experience, and personal growth I gained over the last five years in his lab. I thank Dr. J. David Miller for providing stimulating discourse, travel and collecting opportunities, and of course the unique opportunity to work on this project, which proved to be an exciting and captivating experience. I hope that we can continue collaborating on this and other projects in the near future. Myron Smith provided support and advice throughout this process. The Carleton University Graduate Administrators Darlene Moss and Lisa Chiarel...

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Investigation and Expression of the Secoisolariciresinol Dehydrogenase Gene Involved in Podophyllotoxin Biosynthesis

Cited by 10 publications

References 35 publications

Mollisiaceae: An overlooked lineage of diverse endophytes

Mollisiaceae: An overlooked lineage of diverse endophytes

Plant Endophytes and Epiphytes: Burgeoning Sources of Known and “Unknown” Cytotoxic and Antibiotic Agents?

A Taxonomic and Phylogenetic Investigation of Conifer Endophytes of Eastern Canada

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