Références sur les Plantes

Label: Biopharming Bioengineering Keywords: Gene silencing GMD VIGS RNAi plant N-glycosylation recombinant proteins Abstract: Production of pharmaceutical glycoproteins in plants has many advantages in terms of safety and reduced costs. However, plant-produced glycoproteins have N-glycans with plant-specific sugar residues (core -1,2-xylose and -1,3-fucose) and a Lewis a (Lea) epitope, i.e., Gal (1-3)[Fuc (1-4)]GlcNAc. Because these sugar residues and glycan structures seemed to be immunogenic, several attempts have been made to delete them by repressing their respective glycosyltransferase genes. However, until date, such deletions have not been successful in completely eliminating the fucose residues. In this study, we simultaneously reduced the plant-specific core α-1,3-fucose and ±-1,4-fucose residues in the Lea epitopes by repressing the Guanosine 5'diphosphate (GDP)-D-mannose 4,6-dehydratase (GMD) gene, which is associated with GDP-L-fucose biosynthesis, in Nicotiana benthamiana plants. Repression of GMD was achieved using virus-induced gene silencing (VIGS) and RNA interference (RNAi). The proportion of fucose-free N-glycans found in total soluble protein from GMD gene-repressed plants increased by 80% and 95% following VIGS and RNAi, respectively, compared to wild-type plants. A small amount of putative galactose substitution in N-glycans from the NbGMD gene-repressed plants was observed, similar to what has been previously reported GMD-knockout Arabidopsis mutant. On the other hand, the recombinant mouse granulocyte-macrophage colony-stimulating factor (GMCSF) with fucose-deleted N-glycans was successfully produced in NbGMD-RNAi transgenic N. benthamiana plants. Thus, repression of the GMD gene is thus very useful for deleting immunogenic total fucose residues and facilitating the production of pharmaceutical glycoproteins in plants.

URL: http://dx.doi.org/10.1111/j.1467-7652.2010.00553.x Author Address: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Toyohira-ku, Sapporo, Japan XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Author: Matthes Michaela, Bruce Toby, Ton Jurriaan, Verrier Paul, Pickett John, Napier Johnathan, Year: 2010 Title: * The transcriptome of cis-jasmone-induced resistance in Arabidopsis thaliana and its role in indirect defence.

Secondary Title: Planta 232, 5, 1163-1180.

Publisher: Springer Berlin / Heidelberg Date: 2010-10-01 ISBN/ISSN: 0032-0935 Label: InRe Physiol Keywords: Biomedical and Life Sciences - Indirect defence - Jasmonate signalling - cis-Jasmone - Tritrophic interactions Abstract: cis-jasmone (CJ) is a plant-derived chemical that enhances direct and indirect plant defence against herbivorous insects. To study the signalling pathway behind this defence response, we performed microarraybased transcriptome analysis of CJ-treated Arabidopsis plants. CJ influenced a different set of genes from the structurally related oxylipin methyl jasmonate (MeJA), suggesting that CJ triggers a distinct signalling pathway. CJ is postulated to be biosynthetically derived from jasmonic acid, which can boost its own production through transcriptional up-regulation of the octadecanoid biosynthesis genes LOX2, AOS and OPR3. However, no effect on these genes was detected by treatment with CJ. Furthermore, CJ-responsive genes were not affected by mutations in COI1 or JAR1, which are critical signalling components in MeJA response pathway. Conversely, a significant proportion of CJ-inducible genes required the three transcription factors TGA2, TGA5 and TGA6, as well as the GRAS regulatory protein SCARECROW-like 14 (SCL14), indicating regulation by a different pathway from the classical MeJA response. Moreover, the biological importance was demonstrated in that mutations in TGA2, 5, 6, SCL14 and the CJ-inducible gene CYP81D11 blocked CJ-induced attraction of the aphid parasitoid Aphidius ervi, demonstrating that these components play a key role in CJ-induced indirect defence. Collectively, our results identify CJ as a member of the jasmonates that controls indirect plant defence through a distinct signalling pathway.

Notes: 64 Ref. URL: http://dx.doi.org/10.1007/s00425-010-1244-4 Author Address: (1) Biological Chemistry Department, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK