ISAAA. Pocket K No. 34

RNAi for Crop Improvement   RNA interference (RNAi) is a method of blocking gene function by inserting short sequences of ribonucleic acid (RNA) that match part of the target gene’s sequence, thus no proteins are produced. Since Science named it as “Breakthrough of the Year” and Fortune magazine hailed it as “Biotech’s Billion Dollar Breakthrough”…

J.S. Yadav et al. 2011.

RNAi‐mediated resistance to Cassava brown streak Uganda virus in transgenic cassava   Cassava brown streak disease (CBSD), caused by Cassava brown streak Uganda virus(CBSUV) and Cassava brown streak virus (CBSV), is of new epidemic importance to cassava (Manihot esculenta Crantz) production in East Africa, and an emerging threat to the crop in Central and West Africa. This study demonstrates…

Wagaba, H., et al. 2017

Field level RNAi-mediated resistance to Cassava brown streak disease across multiple cropping cycles and diverse East African agro-ecological locations   Cassava brown streak disease (CBSD) presents a serious threat to cassava production in East and Central Africa. Currently, no cultivars with high levels of resistance to CBSD are available to farmers. Transgenic RNAi technology was…

E. Ogwok et al. 2012

Transgenic RNA interference (RNAi)‐derived field resistance to cassava brown streak disease   Cassava brown streak disease (CBSD), caused by the Ipomoviruses Cassava brown streak virus (CBSV) and Ugandan Cassava brown streak virus (UCBSV), is considered to be an imminent threat to food security in tropical Africa. Cassava plants were transgenically modified to generate small interfering RNAs (siRNAs) from truncated…

Nehra, N. and Taylor, N. 2015

Improving Crops with RNAi   RNA interference (RNAi)—the process by which small interfering RNAs (siRNAs) bind to and cleave complementary mRNA sequences, inhibiting their translation into proteins—is not new to agriculture. In fact, as a naturally occurring biological process, RNAi was mediating plant metabolism, growth, and pathogen defense long before humans began cultivating crops for…

Hokanson, Karen E. et al. 2016.

Risk assessment of gene flow from genetically engineered virus resistant cassava to wild relatives in Africa: an expert panel report The probability and consequences of gene flow to wild relatives is typically considered in the environmental risk assessment of genetically engineered crops. This is a report from a discussion by a group of experts who…

Gomez, Michael A. et al. 2018.

Simultaneous CRISPR/Cas9‐mediated editing of cassava eIF4E isoforms nCBP‐1 and nCBP‐2 reduces cassava brown streak disease symptom severity and incidence Cassava brown streak disease (CBSD) is a major constraint on cassava yields in East and Central Africa and threatens production in West Africa. CBSD is caused by two species of positive‐sense RNA viruses belonging to the…

A virus-derived stacked RNAi construct confers robust resistance to cassava brown streak disease

Beyene G. et al. 2017

A virus-derived stacked RNAi construct confers robust resistance to cassava brown streak disease Cassava brown streak disease (CBSD) threatens food and economic security for smallholder farmers throughout East and Central Africa, and poses a threat to cassava production in West Africa. CBSD is caused by two whitefly-transmitted virus species: Cassava brown streak virus (CBSV) and Ugandan cassava brown…

VIRCA Plus FAQ’s

1. What is the VIRCA PLUS project? VIRCA Plus is a research project to develop virus disease resistant and nutritionally enhanced cassava varieties that will empower African smallholder farmers and improve the health status of consumers. Launched in 2016, VIRCA Plus builds on the success of two predecessor projects. The Virus Resistant Cassava for Africa…