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Living Modified Organism
(LMO)
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Poplar with modified wood composition
EN
hpCSE
No
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- Organization: VIB - Flanders Interuniversity Institute for Biotechnology () | BCH-CON-SCBD-42293-1Organization:VIB - Flanders Interuniversity Institute for Biotechnology ()Rijvisschestraat 120 9052 Zwijnaarde, Belgium Tel.: +09 244 66 11,
, BelgiumPhone:Fax: +09 244 66 10,Email: vib@vib.be,Website: www.vib.be,
The genetically modified grey poplars (Populus canescens / Populus alba x Populus tremula) have an altered wood composition resulting from the silencing of the caffeoyl shikimate esterase enzyme. To achieve this downregulation, the modified trees express a hairpin RNA with homology to caffeoyl shikimate esterase 2, which triggers an RNA interference response and results in the directed degradation of endogenous caffeoyl shikimate esterase messenger RNA. The downregulation of the gene reduces the synthesis of monolignols, which are the basic building blocks of lignin. Thus, the tress have a modified cell wall (and wood) composition, possessing less lignin and more cellulose. In addition, the modified poplars contain an Escherichia coli neomycin phosphotransferase II gene, which was used for kanamycin or neomycin selection during transformation.
The term “Recipient organism” refers to an organism (either already modified or non-modified) that was subjected to genetic modification, whereas “Parental organisms” refers to those that were involved in cross breeding or cell fusion.
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BCH-ORGA-SCBD-101269-5 Organism Populus canescens (Gray poplar, Grey poplar, Hybrid poplar)Trees
Female clone 717-1B4
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pK7GWIWG2II-CSE
EN
- Agrobacterium-mediated DNA transfer
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0.333 kb
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0.255 kb
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1.397 kb
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0.306 kb
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0.226 kb
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0.026 kb
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0.120 kb
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0.026 kb
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0.276 kb
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0.703 kb
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0.377 kb
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0.026 kb
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0.120 kb
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0.026 kb
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1.036 kb
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0.200 kb
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Some of these genetic elements may be present as fragments or truncated forms. Please see notes below, where applicable.
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BCH-GENE-SCBD-100382-2 Chloramphenicol-acetyl-transferase | Escherichia coli (ECOLX)Protein coding sequence | Resistance to antibiotics (Chloramphenicol)
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BCH-GENE-SCBD-103358-4 AttB λ attachment site | Escherichia coli (ECOLX)Excision-integration site
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BCH-GENE-SCBD-100270-6 Nopaline Synthase Gene Promoter | Agrobacterium tumefaciens (Agrobacterium)Promoter
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BCH-GENE-SCBD-15001-5 Neomycin Phosphotransferase II | Escherichia coli (ECOLX)Protein coding sequence | Resistance to antibiotics (Kanamycin)
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BCH-GENE-SCBD-100290-6 CaMV 35S terminator | Cauliflower mosaic virus (CaMV)Terminator
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BCH-GENE-SCBD-100287-7 CaMV 35S promoter | Cauliflower mosaic virus (CaMV)Promoter
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BCH-GENE-SCBD-100269-8 Nopaline Synthase Gene Terminator | Agrobacterium tumefaciens (Agrobacterium)Terminator
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BCH-GENE-SCBD-277091-1 Caffeoyl shikimate esterase 2 hpRNA | Populus tremula x Populus alba (Gray Poplar)Double-stranded RNA
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BCH-GENE-SCBD-101415-9 Ti plasmid left border repeat | Agrobacterium tumefaciens (Agrobacterium)Plasmid vector
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BCH-GENE-SCBD-277094-1 Arabidopsis thaliana chromosome V intron | Arabidopsis thaliana (Thale cress, Mouse-ear cress, Arabidopsis, ARATH)Intron
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BCH-GENE-SCBD-101416-7 Ti plasmid right border repeat | Agrobacterium tumefaciens (Agrobacterium)Plasmid vector
The modified poplar contains two genetic cassettes encoding Escherichia coli neomycin phosphotransferase II (nptII) and a Populus canescens caffeoyl shikimate esterase (cse) RNA interference (RNAi) suppression construct.
The nptII coding sequence is under control of an Agrobacterium tumefaciens nopaline synthase promoter and terminator.
The cse RNAi suppression cassette is under control of a Cauliflower mosaic virus 35S promoter and terminator. The coding sequence from this cassette contains two complementary (inverted) sequences with homology to cse, separated Arabidopsis thaliana introns and an E. coli chloramphenicol-acetyl-transferase sequence. Upon transcription, the cse sequences base pair due to complementarity (sense-antisense orientations), while the additional sequences initially form a loop. Following the base pairing and the splicing (due to the intron sequences present), a double stranded, hairpin RNA structure is formed. This will trigger an RNAi response in the cell, which will process the hairpin RNA into small interfering RNA. Thus, no protein is expected to be translated from this cassette, including the chloramphenicol-acetyl-transferase. Due to the nature of the Cauliflower mosaic virus promoter, high levels of transcription are expected from this gene cassette.
Note:
The nptII coding sequence is under control of an Agrobacterium tumefaciens nopaline synthase promoter and terminator.
The cse RNAi suppression cassette is under control of a Cauliflower mosaic virus 35S promoter and terminator. The coding sequence from this cassette contains two complementary (inverted) sequences with homology to cse, separated Arabidopsis thaliana introns and an E. coli chloramphenicol-acetyl-transferase sequence. Upon transcription, the cse sequences base pair due to complementarity (sense-antisense orientations), while the additional sequences initially form a loop. Following the base pairing and the splicing (due to the intron sequences present), a double stranded, hairpin RNA structure is formed. This will trigger an RNAi response in the cell, which will process the hairpin RNA into small interfering RNA. Thus, no protein is expected to be translated from this cassette, including the chloramphenicol-acetyl-transferase. Due to the nature of the Cauliflower mosaic virus promoter, high levels of transcription are expected from this gene cassette.
Note:
- For more information on RNAi, kindly refer to the "Please describe how the expression of the gene(s) was affected" section of this record below.
Upon transcription of the cse RNAi suppression cassette, a hairpin RNA will be formed with double stranded secondary structure and then an RNA interference response will be triggered. The hairpin RNA will complex with DICER, which will cleave the hairpin RNA into small interfering RNA of 21 to 24 nucleotides in length. Following this, these double stranded small interfering RNAs will then associate with ARGONAUTE, which will unwind the duplex, leaving one strand associated with ARGONAUTE. This protein-RNA complex is now the activated RNA-induced silencing complex (RISC), which will then use the remaining strand of small interfering RNA as a guide to target messenger RNA that has sequence homology to it. Thus, the cellular response is directed at messenger RNA encoding full-length cse, resulting in degradation of the mRNA, reduction in the overall translation of the protein and silencing of expression of the endogenous cse gene.
- Research
- Timber
EN
EN
| Record type | Field | Record(s) | |
|---|---|---|---|
| Risk Assessment generated by a regulatory process | Living modified organism(s) | 1 | |
