ACS-BVØØ1-3 - Liberty Link™ sugarbeet | BCH-LMO-SCBD-14763 | Living Modified Organism | Biosafety Clearing-House


Living Modified Organism (LMO)

Decisions on the LMO Risk Assessments  
published: 05 Jun 2006 last updated: 15 May 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.
Liberty Link™ sugarbeet
Sugar beet tolerant to the herbicide glufosinate, created through introduction of the phosphinothricin acetyltransferase (pat) gene from Streptomyces viridochromogenes, an aerobic soil bacteria, which confers tolerance to the herbicide Phosphinothricin (Glufosinate ammonium).  Neomycin phosphotransferase II (npt II) confers tolerance to the antibiotic kanamycin.
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-15002-4 Phosphinothricin N-acetyltransferase gene | Streptomyces viridochromogenes (STRVR)
    Protein coding sequence | Resistance to herbicides (Glufosinate)
  • BCH-GENE-SCBD-15001-5 Neomycin Phosphotransferase II | Escherichia coli (ECOLX)
    Protein coding sequence | Resistance to antibiotics (Kanamycin)
  • BCH-GENE-SCBD-100287-7 CaMV 35S promoter | Cauliflower mosaic virus (CaMV)
  • BCH-GENE-SCBD-14972-12 Phosphinothricin N-acetyltransferase gene | Streptomyces hygroscopicus (STRHY)
    Protein coding sequence | Resistance to herbicides (Glufosinate)
  • BCH-GENE-SCBD-100290-6 CaMV 35S terminator | Cauliflower mosaic virus (CaMV)
  • BCH-GENE-SCBD-100270-6 Nopaline Synthase Gene Promoter | Agrobacterium tumefaciens (Agrobacterium)
  • BCH-GENE-SCBD-100271-5 Octopine Synthase Gene Terminator | Agrobacterium tumefaciens (Agrobacterium)
The native pat gene was modified to reduce the G/C content of the DNA sequence and to a plant preferred codon sequence. The native and modified genes share 70% sequence homology however there was no change to the amino acid sequence.

Southern blot and PCR analysis indicated that a single insert of the T-DNA was integrated into the host genome and single copies of each of the bar and nptII genes.
LMO characteristics
  • Food
  • Feed
Detection method(s)
Additional Information
The sugar beet line T120-7 was genetically engineered to express tolerance to glufosinate ammonium, the active ingredient in phosphinothricin herbicides (Basta®, Rely®, Finale®, and Liberty®). Glufosinate ammonium acts by inhibiting the plant enzyme glutamine synthetase, a key enzyme that detoxifies ammonia by incorporating it into glutamine. Inhibition of this enzyme leads to an accumulation of ammonia in the plant tissues, which kills the plant within hours of application. Phosphinothricin herbicides applied at rates recommended for effective weed control are toxic to conventional sugar beet varieties. The modified T120-7 line permits growers to use phosphinothricin-containing herbicides for weed control in the cultivation of sugar beet.

Glufosinate tolerance in T120-7 sugar beet is the result of the introduction of the pat gene into the beet genome via Agrobacterium-mediated transformation. The pat gene was isolated from the common soil fungus, Streptomyces viridochromogenes, and encodes the enzyme phosphinothricin-N-acetyltransferase (PAT). PAT catalyses the acetylation of phosphinothricin which detoxifies it into an inactive compound.
Records referencing this document Show in search
Record type Field Record(s)
Risk Assessment generated by an independent or non-regulatory process Living modified organism(s) 2
Country's Decision or any other Communication Living modified organism(s) 3
Risk Assessment generated by a regulatory process Living modified organism(s) 2