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Living Modified Organism (LMO)
  |  
Decisions on the LMO Risk Assessments  
published: 20 May 2019 last updated: 21 May 2019
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.
Cassava modified for increased starch yield, elevated photosynthesis, and ACMV resistance
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Not available
No
The cassava has been modified to elevate the storage root yield, increase photosynthesis, and have RNA interference-mediated resistance to African Cassava Mosaic Virus (ACMV). The expression of PsGPT and AtNTT promote starch biosynthesis in the amyloplasts through the increased uptake of ATP and glucose-6-phosphate precursors. The cassava also has been modified for increased photosynthetic capacity via AtTMT1, which increases expression of photosynthetic genes, and increases sugar export to the roots. The plant is also resistant to ACMV through the production of hairpin RNA targeting AC1, mediating an RNA interference against the virus and preventing viral replication.
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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.
Cultivar 60444
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  • Cassava modified for high starch yield, increased photosynthetic capacity, and ACMV resistance
    | International Institute of Tropical Agriculture(IITA) | Changes in physiology and/or production (Growth rate, Photoperiod response, Yield), Changes in quality and/or metabolite content (Carbohydrates), Increased photosynthetic rate, Resistance to antibiotics (Hygromycin), Tolerance to abiotic stress (Cold / Heat)
  • Cassava modified for high starch yield, increased photosynthetic capacity, and ACMV resistance
    | International Institute of Tropical Agriculture(IITA) | Changes in physiology and/or production (Growth rate, Yield), Changes in quality and/or metabolite content (Carbohydrates), Increased photosynthetic rate, Resistance to antibiotics (Hygromycin), Resistance to diseases and pests (Viruses), Selectable marker genes and reporter genes, Tolerance to abiotic stress (Cold / Heat)
Characteristics of the modification process
p134GG
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  • 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-114674-3 Granule Bound Starch Synthase 1 Promoter | Manihot esculenta (Cassava, Brazilian arrowroot, Yuca, Manioc, Mandioca, MANES)
    Promoter
  • BCH-GENE-SCBD-110671-1 Glucose-6-phosphate/phosphate-translocator gene | Pisum sativum (Garden pea, PEA)
    Protein coding sequence | Changes in physiology and/or production (Yield),Changes in quality and/or metabolite content (Carbohydrates)
  • BCH-GENE-SCBD-100269-8 Nopaline Synthase Gene Terminator | Agrobacterium tumefaciens (Agrobacterium)
    Terminator
  • BCH-GENE-SCBD-114675-1 Solanum tuberosum Soluble Starch Synthase 3 promoter | Solanum tuberosum (Potato, SOLTU)
    Promoter
  • BCH-GENE-SCBD-114676-2 Nucleoside Triphosphate Translocator 1 | Arabidopsis thaliana (Thale cress, Mouse-ear cress, Arabidopsis, ARATH)
    Protein coding sequence | Changes in physiology and/or production (Yield),Changes in quality and/or metabolite content (Carbohydrates)
  • BCH-GENE-SCBD-103774-1 Mannopine synthase gene terminator | Agrobacterium tumefaciens (Agrobacterium)
    Terminator
  • BCH-GENE-SCBD-114684-1 Ribulose 1,5-bisphosphate carboxylase/oxygenase small subunit 3B promoter | Arabidopsis thaliana (Thale cress, Mouse-ear cress, Arabidopsis, ARATH)
    Promoter
  • BCH-GENE-SCBD-114699-2 5' Untranslated region from Potato Virus X | Potato virus X (PVX)
    5' Untranslated Region
  • BCH-GENE-SCBD-114686-2 Tonoplast Monosaccharide Transporter 1 | Arabidopsis thaliana (Thale cress, Mouse-ear cress, Arabidopsis, ARATH)
    Protein coding sequence | Altered photosynthesis,Changes in physiology and/or production (Growth rate, Photoperiod response, Yield)
  • BCH-GENE-SCBD-103067-9 Transcript 7 gene 3' untranslated region | Agrobacterium tumefaciens (Agrobacterium)
    Terminator
  • BCH-GENE-SCBD-114703-1 Ribulose 1,5-bisphosphate carboxylase/oxygenase small subunit 2B promoter | Arabidopsis thaliana (Thale cress, Mouse-ear cress, Arabidopsis, ARATH)
    Promoter
  • BCH-GENE-SCBD-114697-1 Replication Associated Gene | African cassava mosaic virus (ACMV)
    Protein coding sequence | Resistance to diseases and pests (Viruses)
  • BCH-GENE-SCBD-100290-6 CaMV 35S terminator | Cauliflower mosaic virus (CaMV)
    Terminator
  • BCH-GENE-SCBD-100270-6 Nopaline Synthase Gene Promoter | Agrobacterium tumefaciens (Agrobacterium)
    Promoter
  • BCH-GENE-SCBD-14991-8 Hygromycin B phosphotransferase gene | Escherichia coli (ECOLX)
    Protein coding sequence | Resistance to antibiotics (Hygromycin),Selectable marker genes and reporter genes
  • BCH-GENE-SCBD-114698-2 CMV1 5' Untranslated region | Cucumber mosaic virus (CMV)
    5' Untranslated region
Overexpression of PsGPT and AtNTT1 in roots:
The Pisum sativum Glucose 6-phosphate/Phosphate Translocator (PsGPT) is under the control of the Manihot esculenta Granule Bound Starch Synthase 1 promoter and the Agrobacterium tumefaciens nopaline synthase terminator.  Note: PsGPT contains both the 5' untranslated region (5' UTR) and the coding sequence.

Arabidopsis thaliana Nucleoside Triphoisphate Translocator 1 (AtNTT1) is transcribed from Solanum tuberosum Soluble Starch Synthase 3 promoter and the corresponding transcript is translated from the Cucumber Mosaic Virus 1 5' UTR. Transcription and translation terminate at the 3' untranslated region (3' UTR) of A. tumefaciens mannopine synthase.

PsGPT codes for a membrane-bound translocator that transports glucose-6-phosphate into the amyloplasts. Similarly, AtNTT1 encodes a translocator for transporting ATP into the amyloplasts. Starch biosynthesis is dependent on the presence of both glucose-6-phosphate and ATP. Thus, PsGPT and AtNTT1 together promote starch biosynthesis in the amyloplasts, leading to a greater accumulation of starch in the storage roots of the cassava plants.

Overexpression of AtTMT1 in leaves:
A. thaliana Tonoplast Monosaccharide Transporter 1 (AtTMT1) is under transcriptional control of A. thaliana Rubsico Small Subunit 3B promoter, translational control of Potato Virus X 5' UTR, and A. tumefaciens Gene 7 terminator. AtTMT1 encodes a membrane protein responsible for transferring glucose from the cytosol into vacuole. Overexpression of AtTMT1 leads to an increased expression of photosynthetic genes, a decrease in sugar consumption for cellular respiration, a reduction of nocturnal carbon dioxide loss, and increased export capacity of sugars from the leaves. Elevated photosynthetic carbon fixation and sugar export to the roots, leads to increased yield.

RNA interference targeting ACMV:
The RNA interference (RNAi) cassette targets the African Cassava Mosaic Virus replication associated gene (AC1) through the production of hairpin RNA (hpRNA). Transcription commences from the A. thaliana Rubisco small subunit 2B promoter and transcribes an inverted repeat of sequences complementary to AC1, before terminating at the Cauliflower Mosaic Virus 35S terminator (CaMV 35 terminator). After transcription, the inverted repeat base pairs to form the hpRNA structure. The hairpin structure is similar to double stranded RNA, which then proceeds to elicit an RNAi response in the host plant. Following processing of the hpRNA, the host's RNAi proteins target viral transcripts with complementary base pairs to the AC1 inverted repeats. Thus, the RNAi response prevents viral replication and infection via the destruction of AC1, a gene essential for viral replication.

Selectable marker:
For the selection of transformed embryos, hygromycin B was used. E. coli Hygromycin B phosphotransferase is under the control of the Agrobacterium tumefaciens nopaline synthase
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LMO characteristics
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  • Food
  • Research
Detection method(s)
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Additional Information
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