SYN-IR6Ø4-5 - Agrisure™ RW Rootworm-Protected maize | BCH-LMO-SCBD-15105 | Living Modified Organism | Biosafety Clearing-House

Living Modified Organism (LMO)
Decisions on the LMO Risk Assessments  
last updated: 19 Apr 2013
Living Modified Organism identity
The image below identifies the LMO through its unique identifier, trade name and a link to this page of the BCH. Click on it to download a larger image on your computer. For help on how to use it go to the LMO quick-links page.
Agrisure™ RW Rootworm-Protected maize
MIR604 is a genetically modified maize developed to confer field protection against corn root worms.

The cry3A gene from Bacillus thuringiensis codes for a  Bt-toxin (Cry3A), which confers resistance to western corn rootworm (Diabrotica virgifera virgifera), northern corn rootworm (Diabrotica longicornis barberi) and other related coleopteran species.

Expression of the pmi gene from the bacterium Escherichia coli allows the plant to use mannose as a carbon source through production of the PMI protein, and is used as a selectable marker.
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.
Characteristics of the modification process
  • Agrobacterium-mediated DNA transfer
Some of these genetic elements may be present as fragments or truncated forms. Please see notes below, where applicable.
  • BCH-GENE-SCBD-15003-7 Phosphomannose Isomerase gene | Escherichia coli (ECOLX)
    Protein coding sequence | Mannose tolerance,Selectable marker genes and reporter genes
  • BCH-GENE-SCBD-103881-2 Metallothionein-like gene promoter | Zea mays (Maize, Corn, MAIZE)
  • BCH-GENE-SCBD-100269-8 Nopaline Synthase Gene Terminator | Agrobacterium tumefaciens (Agrobacterium)
  • BCH-GENE-SCBD-100362-7 Ubiquitin gene promoter | Zea mays (Maize, Corn, MAIZE)
  • BCH-GENE-SCBD-103627-5 Ubiquitin Intron 1 | Zea mays (Maize, Corn, MAIZE)
  • BCH-GENE-SCBD-43634-3 mCry3A | Bacillus thuringiensis (Bt, Bacillus, BACTU)
    Protein coding sequence | Resistance to diseases and pests (Insects, Coleoptera (beetles), Western corn rootworm (Diabrotica virgifera))
Cry3A gene obtained from Bacillus thuringiensis. The gene was modified for enhanced expression in maize and such that the amino acid sequence of the synthetic version of Cry3A is the same as the native protein, except for the modified serine-protease recognition site.

The pmi gene encodes the enzyme phosphomannose isomerase (PMI) that allows the plants to utilise mannose as a carbon source and is used as a selectable marker.

Truncations at the left and right border junctions of the T-DNA insert as well as nucleotide changes were identified relative to the intended DNA sequence. These substitutions have not resulted in any apparent functional change in PMI as expressed in MIR604.

Southern hybridization data provide confirmatory evidence to support the Taqman PCR analysis that Corn MIR604 contains a single copy of mcry3A gene and the pmi gene.

Corn MIR604 contains a single copy of the MTL and ZmUbilnt promoters, without any vector backbone sequences present in pZM26. Sequence analysis revealed that truncations and deletions occurred but have no effect on the efficacy of the T-DNA insert. Three base pair changes were noted; one occurred in the regulatory region and does not encode for a protein; two other base pair changes occurred within the coding region but these amino acid changes did not result in any apparent functional change in the new insert.

As expected for the mcry3A, pmi, MTL and ZmUbilnt probes the Kpn1 digest resulted in a single hybridization band demonstrating that a single copy of each element is present in Corn MIR604.  Additionally, for the full length backbone probe, lack of hybridization demonstrates the absence of any pZM26 vector backbone sequences being incorporated into corn MIR604 during the transformation process.
LMO characteristics
Additional Information