Viral resistant cassava with increased levels of zinc and iron | BCH-LMO-SCBD-115144 | Living Modified Organism | Biosafety Clearing-House

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Living Modified Organism (LMO)

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last updated: 23 Aug 2019
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Viral resistant cassava with increased levels of zinc and iron
EN
D9001-985005
  • - Person: National Root Crops Research Institute | BCH-CON-NG-115060-3
    Person
    National Root Crops Research Institute
    Km 8 Ikot Ekpene Road, PMB 7006
    Umuahia, Abia State
    , Nigeria
    Phone: +2349035068714,
    Fax:
    Website:
    Related Organization
    National  Root Crops Research Institute (NRCRI)
    Academic or research institute
    Km 8 Ikot Ekpene Road, PMB 7006
    Umuahia, Abia State
    , Nigeria
    Phone: +2349035068714,
    Fax:
    Website:
Cassava (Manihot esculenta Crantz) was modified to express Arabidopsis thaliana FERRITIN 1 and IRON-REGULATED TRANSPORTER 1 to increase the levels of iron and zinc. The modified cassava additionally contains an RNAi cassette to target the coat proteins of Cassava Brown Streak Virus and Ugandan Cassava Brown Streak Virus and convey resistance to these viruses, the causal agents of Cassava brown streak disease.

Previous overepxression of FER1 and IRT1 increased iron and zinc levels by 7-18 times 3-10 times, respectively.

A selectable marker, Escherichia coli neomycin phosphotransferase II, was also included for selection of transformants using kanamycin.
EN
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.
Cassava cultivar: TMS 98/0505
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  • Viral resistant cassava with increased levels of zinc and iron
    | National Root Crops Research Institute(NRCRI) | Changes in quality and/or metabolite content, Increased iron levels, Increased zinc levels, Resistance to antibiotics (Kanamycin), Resistance to CBSV, Resistance to diseases and pests (Viruses), Resistance to UCBSV, Selectable marker genes and reporter genes
  • Cassava modified for increased levels of iron and zinc
    | National Root Crops Research Institute(NRCRI) | Changes in quality and/or metabolite content, Increased levels of iron, Increased levels of zinc, Resistance to antibiotics (Kanamycin), Selectable marker genes and reporter genes
  • Cassava modified for increased levels of iron and zinc
    | National Root Crops Research Institute(NRCRI) | Changes in quality and/or metabolite content, Increased levels of iron, Increased levels of zinc, Resistance to antibiotics (Kanamycin), Selectable marker genes and reporter genes
  • Cassava brown streak disease-resistant cassava
    | National Root Crops Research Institute(NRCRI) | Resistance to antibiotics (Kanamycin), Resistance to CBSV, Resistance to diseases and pests (Viruses), Resistance to UCBSV
Characteristics of the modification process
p9001
EN
  • Agrobacterium-mediated DNA transfer
Some of these genetic elements may be present as fragments or truncated forms. Please see notes below, where applicable.
RNA interference cassette:
Transcription of the cassette produces a hairpin RNA (hpRNA). RNA polymerase is recruited to the Cassava vein mosaic virus promoter and then transcribes: two segments of Cassava Brown Streak Virus (CBSV) and the Ugandan Cassava Brown Streak Virus (UCBSV) coat protein (sense orientation), the Flaveria trinervia pyruvate orthophosphate dikinase intron 3 (PDK), and CBSV and UCBSV coat protein (anti-sense orientation). Transcription stops at the Agrobacterium tumefaciens nopaline synthase (nos) terminator. The produced RNA then can form a double stranded segment due to the interstrand homology between the CBSV and UCBSV coat protein segments and the flexible linker/loop, PDK. The double stranded segment of the hpRNA is sufficient to trigger an RNA interference (RNAi) response. The host cell machinery then processes the hpRNA into small interfering RNA, which is used to guide the targeted degradation of RNA molecules with sequence homology. In this case, infecting viral transcripts are degraded by the host cell.

Iron-regulated transporter cassette:
Transcription of the Arabidopsis thaliana iron-regulated transporter 1 is under control of the A. thaliana phloem protein 2-A14 promoter and terminator.

Ferritin-1 cassette:
Arabidopsis thaliana ferritin-1 is under transcriptional control of the Solanum tuberosum patatin-1 promoter and terminator.

Selectable marker cassette:
Transcription of the Escherichia coli neomycin phosphotransferase II occurs from the duplicated enhanced Cauliflower Mosaic Virus 35S promoter and terminates at the nos terminator.

Please note all genetic elements were in the anti-sense orientation.
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LMO characteristics
EN
  • Food
  • Research
Detection method(s)
The hpRNA cassette containing the coat proteins of CBSV and UCBSV is expected to be processed into small interfering RNA between 21-24 nucleotides in length. Due to this processing, proteins are not expected to be produced from this transcript.
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Additional Information
Please note:
The transformation event D9001-985005 is a placeholder. A secondary transformation event (D9001-985007) is expected to have similar introduced genetic elements. This field will be updated once more information is available and if one of the events is chosen for commercialization.
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