{Reference Type}: Journal Article
{Author}: Rachmawati, Rina; Kinoshita, Hiroshi; Nihira, Takuya
{Year}: 2013
{Title}: Establishment of Transformation System in Cordyceps Militaris by using Integration Vector with Benomyl Resistance Gene
{URL}: http://www.sciencedirect.com/science/article/pii/S1878029613000248
{Tag}: 0
{Star}: 0
{Journal}: Procedia Environmental Sciences
{Volume}: 17
{Issue}: 0
{Pages}: 142-149
{Date Displayed}: 2013///
{Alternate Title}: Procedia Environmental Sciences
The 3rd International Conference on Sustainable Future for Human Security, SUSTAIN 2012, 3-5 November 2012, Clock Tower Centennial Hall, Kyoto University, JAPAN
{ISBN/ISSN}: 1878-0296
{Keywords}: Cordyceps militaris; transformation system; laeA
{Abstract}: To enhance the production of bioactive compounds efficiently from filamentous fungi, the secondary metabolism was activated by genetic engineering. laeA gene which is regarded as a global regulator of secondary metabolism in filamentous fungi was introduced into five strains of entomopathogenic fungi Cordyceps militaris. Since there was no reported transformation systemin in C. militaris, this research aimed at establishing the transformation system in this species. Benomyl and its resistance gene were adopted as a marker system to facilitate the introduction of laeA fragments into C.militaris under the control of Bauveria bassiana pGPD promoter. The minimum inhibitory concentration of benomyl against C.militaris was 1.5 μg/ml and a transformation efficiency of 7 colonies/μg DNA was obtained by the protoplast-PEG method with the vector pBT6, containing the benomyl resistance gene. Southern analysis of the transformants confirmed that pBT6 exists as an integration vector, and laeA integrated in the genome at random. The observation of the changes in metabolism of laeAtransformants was conducted using HPLC equipped with photodiode array method. The transformants harboring heterogeneous laeA showed enhanced productivity of secondary metabolites, compared to their wild type strains.

{Reference Type}: Journal Article
{Author}: Xiong, C.; Xia, Y.; Zheng, P.; Wang, C.
{Year}: 2013
{Title}: Increasing oxidative stress tolerance and subculturing stability of Cordyceps militaris by overexpression of a glutathione peroxidase gene
{URL}: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=22828981&query_hl=1
{Tag}: 0
{Star}: 0
{Journal}: Appl Microbiol Biotechnol
{Volume}: 97
{Issue}: 5
{Pages}: 2009-15
{DOI}: 10.1007/s00253-012-4286-7
{Date Displayed}: 2013 Mar
{Date}: 2013-03-01
{Type of Work}: Journal Article; Research Support, Non-U.S. Gov't
{Accession Number}: 22828981
{Abstract}: Like other filamentous fungi, the medicinal ascomycete Cordyceps militaris frequently degenerates during continuous maintenance in culture by showing loss of the ability to reproduce sexually or asexually. Degeneration of fungal cultures has been related with cellular accumulation of reactive oxygen species (ROS). In this study, an antioxidant glutathione peroxidase (Gpx) gene from Aspergillus nidulans was engineered into two C. militaris strains, i.e., the Cm01 strain which can fruit normally and the Cm04 strain which has lost the ability to form fruiting bodies on different media through subculturing. The results showed   that the mitotically stable mutants had higher Gpx activities and stronger capacity to scavenge cellular ROS than their parental strains. Most significantly, the fruiting ability of Cm04 strain was restored by overexpression of the antioxidant enzyme. However, after being successively transferred for up to ten generations, two of three Cm04 mutants again lost the ability to fruit on   insect pupae while Cm01 transformants remained fertile. This study confirms the relationship between fungal culture degeneration and cellular ROS accumulation. Our results indicate that genetic engineering with an antioxidant gene can be an   effective way to reverse fungal degeneration during subculturing.
{Author Address}: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
{Language}: eng

{Reference Type}: Journal Article
{Author}: Hannula, S. E.; de Boer, W.; Baldrian, P.; van Veen, J. A.
{Year}: 2013
{Title}: Effect of genetic modification of potato starch on decomposition of leaves and tubers and on fungal decomposer communities
{Tag}: 0
{Star}: 0
{Place Published}: Langford Lane, Kidlington, Oxford, OX5 1GB, United Kingdom
{Journal}: Soil Biology and Biochemistry
{Volume}: 58
{Pages}: 88-98
{Date Displayed}: 2013
{ISBN/ISSN}: 00380717
{Original Publication}: Elsevier Ltd
{Keywords}: Plants (botany); Cultivation; Genetic engineering; Histology; Manganese; Starch; Tissue; Tubes (components); Yeast
{Abstract}: As part of a risk evaluation of growing genetically modified crops, we investigated the effects of a genetic modification of starch quality (increased level of amylopectin) in potato tubers (Solanum tuberosum L.) on the decomposition of tissues (tubers and leaves) as well as on the associated fungal functional and phylogenetic diversity. The weight loss of both leaves and tubers in litterbags was analysed after 1, 3 and 6 months of incubation in soils and combined with measurements of fungal extracellular enzyme activities (laccases, Mn-peroxidases and cellulases) as well as molecular analyses of the fungal community (ITS regions and cellobiohydrolase I (cbhI) genes). The study revealed that initial (after one month) decomposition of both tubers and leaves of the parental isoline was significantly faster than that of the genetically modified (GM)-variety. This coincided with differences in fungal community composition. After this initial difference, no significant differences in any of the parameters measured could be detected after 3 and 6 months of decomposition illustrating the transient nature of the initial difference between the cultivars. Thus, it can be concluded that the starch modified tubers are not harmful to the fungal decomposer community and that despite initial differences in decomposition, the final decomposition rate of tissues from the GM-variety was similar to that of tissues from the parental variety. Furthermore, interesting dynamics of fungal phyla and species during decomposition were observed; the basidiomycetal yeasts and ascomycetes were primary colonizers of the potato tissue while basidiomycetes were dominant in the more decomposed and lignin-rich litter.   2012 Elsevier Ltd.
{Notes}: Compilation and indexing terms, Copyright 2013 Elsevier Inc.
20125115815949
Ascomycetes
Basidiomycetes
CbhI
Fungal diversity
GM-plants
Litter decay
{Author Address}: Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6708 PB Wageningen, Netherlands