CGIAR centers applying CRISPR/Cas to improve roots, tubers, and bananas

One CGIAR centers are now using CRISPR/Cas, a form of genome editing, to help speed up the development of improved high-yielding roots, tubers, and bananas (RTB)—these are essential staple food crops in tropical and subtropical countries grown for food security.

Genome editing either silences or knocks out a gene of interest in the plant genome without inserting any foreign gene, which means the resulting product will not be a genetically modified organism (GMO).

RTB crops where gene editing is now being used include banana and yam, led by IITA; potato led by the International Potato Center (CIP); and cassava led by the International Center for Tropical Agriculture (CIAT).

These crops have several common challenges such as diseases, pathogens, pests, and slow breeding methods. Genome editing has the potential to accelerate their breeding.

The centers’ work on RTB crops was shared at a One CGIAR webinar on genome editing held on 29 September. Leena Tripathi, a principal scientist at IITA, spoke in one of the sessions focusing on the genome editing of RTB crops.

“The system for genome editing of banana and yam is already established,” Tripathi told participants. This work is a collaboration between IITA, the University of Iowa, and Michigan State University with funding from the National Science Foundation and Bill & Melinda Gates Foundation under the BREAD project. Tripathi leads genome editing research at IITA and is the country representative for Kenya.

“Whole genome reference sequences and genetic transformation technologies for yam varieties—Dioscorea rotundata and D. alata”—are available, making it possible to apply CRISPR-based genome editing for trait improvement. Subject to funding, yam will be edited for resistance to viruses and anthracnose disease,” Tripathi said.

In banana, Tripathi informed participants about the process of genome editing and its regulation in Kenya, where IITA’s biotechnology research takes place. Currently, work is ongoing to develop bananas resistant to bacterial wilt, fusarium wilt, and banana streak virus.

These traits are not stacked, i.e., they are not all in the same banana variety but in different varieties, each bearing one trait. If everything goes according to plan, the first field trial of genome-edited bananas will be planted in 2021.

Away from scientific research, Tripathi also talked about genome editing regulations across the world. In countries like Bangladesh, India, Indonesia, Kenya, Nigeria, and the Philippines, discussions are ongoing, whereas Argentina, Australia, Brazil, Canada, Chile, Colombia, Israel, Japan, and the USA already have regulations. In these countries, genome-edited crops that do not have any foreign DNA are not regulated as GMOs.

However, in the European Union and New Zealand, genome-edited crops are regulated as GMOs. Regulating a crop as a GMO has financial, time, and adoption implications. Tripathi informed meeting participants that Nigeria and Kenya would most likely not regulate genome-edited crops as GMO, which is good news for farmers in these countries.