Record details

Living Modified Organism identity

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LMO name

Cassava brown streak disease-resistant cassava

Transformation event

D5001-985013

Developer(s)

Record #115138

National Root Crops Research Institute (NRCRI)

Km 8 Ikot Ekpene Road, PMB 7006

Umuahia, Abia

Nigeria

Phone:	+234 (0)8168983790,+2349035068714
Email:	info@nrcri.gov.ng,Ihuomaumezurumba@yahoo.com
Url:	National Root Crops Research Institute

Description

Cassava (Manihot esculenta Crantz) was modified for RNA interference-mediated resistance to Cassava Brown Streak Disease. The modified cassava expresses a hairpin RNA (hpRNA) cassette that contains portions of the coat proteins of Cassava Brown Streak Virus and Ugandan Cassava Brown Streak Virus, the causal agents of Cassava Brown Streak Disease. Transcription of the hpRNA form this cassette guides host cell machinery for targeted degradation of infecting viral transcripts.

A selectable marker, Escherichia coli neomycin phosphotransferase II, was also included for selection of transformants using kanamycin.

Recipient Organism or Parental Organisms

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.

Record #112539

Manihot esculenta - Cassava, Brazilian arrowroot, Yuca, Manioc, Mandioca, MANES

Point of collection or acquisition of the recipient organism

Cassava cultivar: TMS 98/0505

Related LMOs

Record #115144

Viral resistant cassava with increased levels of zinc and iron

National Root Crops Research Institute Changes in quality and/or metabolite content Increased levels of iron Resistance to antibiotics - Kanamycin Tolerance to abiotic stress Tolerance to excess iron

Show detection method(s)

Record #115140

Viral resistant cassava with increased levels of zinc and iron

Changes in quality and/or metabolite content Increased levels of iron Resistance to antibiotics - Kanamycin Tolerance to abiotic stress Tolerance to excess iron

Characteristics of the transformation process

Vector

p5001

Techniques used for the modification

Agrobacterium-mediated DNA transfer

Genetic elements construct

Nopaline Synthase Gene Terminator

#100269

0.27 Kb

Coat protein

#115108

0.90 Kb

Coat Protein

#115110

0.90 Kb

Pyruvate orthophosphate dikinase, Intron 3

#103123

0.78 Kb

Coat Protein

#115110

0.90 Kb

Coat protein

#115108

0.90 Kb

CsVMV promoter

#101900

0.52 Kb

Nopaline Synthase Gene Terminator

#100269

0.25 Kb

Neomycin Phosphotransferase II

#15001

0.80 Kb

CaMV Enhanced 35S promoter

#100366

0.39 Kb

CaMV Enhanced 35S promoter

#100366

0.39 Kb

Further details

Notes regarding the genetic elements introduced or modified in this LMO

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 in inverted orientations and the flexible linker/loop, PDK. The double stranded segment of the hpRNA is sufficient to elicit 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.

Please note all genetic elements were in the anti-sense orientation.

LMO characteristics

Modified traits

Resistance to antibiotics
- Kanamycin
Resistance to diseases and pests
- Viruses
Selectable marker genes and reporter genes
Resistance to CBSV
Resistance to UCBSV

Common use(s)

Food
Research

Detection method(s)

Additional information

Due to the processing of the hpRNA by the host cell DICER protein, it is expected that small interfering RNA 21 to 24 base pairs in length will be present instead. Additionally, the cellular processing means that no proteins are expected to be produced from the hpRNA.

Additional Information

Please note that several lines have been created using the transformation vector p5001. The following transformation events are expected to contain similar genetics:

D5001-985013, D5001-985019, D5001-985022, D5001-985024, D5001-985025, D5001-985026, D5001-985028, D5001-985029, D5001-985030, D5001-985031, D5001-985033 and D5001-985034.

The transformation event is thus a placeholder until further information is uncover and/or a line has been selected for commercialization.

Other relevant website address or attached documents

Virus-Derived Stacked RNAi Construct Confers Robust Resistance to Cassava Brown Streak Disease.pdf