Cassava brown streak disease resistant cassava | BCH-LMO-SCBD-115624 | Living Modified Organism | Biosafety Clearing-House

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Living Modified Organism (LMO)

Decisions on the LMO Risk Assessments  
last updated: 26 Jun 2020
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 brown streak disease resistant cassava
EN
pCRNAi-CBSV-CP
No
The cassava was modified for resistance to Cassava brown streak disease (CBSD) by introducing an RNA interference cassette that targets Cassava brown streak virus (CBSV) coat protein (CP). The production of hairpin RNA by the host cells trigger an RNAi response that is expected to target viral transcripts and prevent viral assembly and thus further infection. Due to conservation of the CP sequence between CBSV and Ugandan cassava brown streak virus, the modified cassava is expected to be resistant to the causal agents of CBSD. A selectable marker, Escherichia coli hygromycin B phosphotransferase, was additionally included for hygromycin selection during transformation.
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.
EN
  • Cassava mosaic disease resistant cassava
    | Masinde Muliro University of Science and Technology(MMUST) | Resistance to African cassava mosaic virus (ACMV), Resistance to antibiotics (Hygromycin), Resistance to diseases and pests (Viruses), Selectable marker genes and reporter genes
  • Cassava mosaic disease resistant cassava
    | Masinde Muliro University of Science and Technology(MMUST) | Resistance to African cassava mosaic virus, Resistance to antibiotics (Hygromycin), Resistance to diseases and pests (Viruses), Selectable marker genes and reporter genes
  • Cassava mosaic disease resistant cassava
    | Masinde Muliro University of Science and Technology(MMUST) | Resistance to African cassava mosaic virus, Resistance to antibiotics (Hygromycin), Resistance to diseases and pests (Viruses), Selectable marker genes and reporter genes
  • Cassava mosaic disease resistant cassava
    | Masinde Muliro University of Science and Technology(MMUST) | Resistance to African cassava mosaic virus, Resistance to antibiotics (Hygromycin), Resistance to diseases and pests (Viruses)
Characteristics of the modification process
pCAMBIA1300
EN
  • Agrobacterium-mediated DNA transfer
 
0.000 kb
 
 
0.525 kb
 
 
0.202 kb
 
 
0.525 kb
 
 
0.000 kb
 
Some of these genetic elements may be present as fragments or truncated forms. Please see notes below, where applicable.
RNA interference cassette
The modified cassava contains an RNA interference (RNAi) cassette designed to target Cassava brown streak virus coat protein (CP). Transcription is initiated from the Cauliflower mosaic virus (CaMV) 35S promoter and terminates at the CaMV 35S terminator. The transcript contains two segments (sense and antisense) of CP separated by a plant synthetic intron. Post-transcription, the intron functions as a loop and allows the sense and antisense segments of CP to base pair, forming hairpin RNA (hpRNA). The hpRNA acts as double stranded RNA (dsRNA), which triggers an RNAi response and the host cell machinery will target CP viral transcripts for degradation.

Note:
- The segment of CP corresponds to positions 538 to 1063 of the CBSV (GenBank accession JN091565.1).
- The source of the CP sequence is CBSV strain TAZ-DES-01.
- Due to the RNAi response, no protein translation is expected from the RNAi cassette.

Selectable marker
Transcription of Escherichia coli hygromycin B phosphotransferase is under transcriptional control of the CaMV 35S promoter and Agrobacterium tumefaciens nopaline synthase terminator.
EN
LMO characteristics
EN
  • Food
Detection method(s)
EN
Additional Information
RNA interference
An RNAi response is an anti-viral response triggered by the recognition of dsRNA. Host DICER recognizes dsRNA, cleaving the dsRNA into small interfering RNA (siRNA), roughly 21-23 bp long (size is host dependent). The siRNA is then bound by ARGONAUTE family proteins, which unwind the duplex, leaving a single strand of the siRNA, and activating the RISC complex. The RISC complex targets transcripts with homology to the siRNA and degrades them.
EN
Records referencing this document Show in search
Record type Field Record(s)
Country's Decision or any other Communication Living modified organism(s) 1
Risk Assessment generated by a regulatory process Living modified organism(s) 1
Living Modified Organism Related LMO(s) 4