An international team of scientists has successfully developed cassava with high-level resistance to cassava mosaic disease (CMD), cassava brown streak disease (CBSD), as well as higher levels of iron and zinc. This is the first time that disease resistance and multiple biofortification traits have been stacked in this manner in a non-cereal crop.
The research builds on a 2019 research that showed increasing the mineral content of cassava storage roots was possible. RNAi-mediated technology was used to achieve resistance to CBSD in two East African and two Nigerian farmer-preferred cultivars along with AtIRT1 (major iron transporter) and AtFER1 (ferritin) transgenes to achieve nutritionally significant levels of iron and zinc in cassava storage roots (145 and 40 µg/g dry weight, respectively).
The research team also tested the cassava to confirm that mineral levels are retained during food processing and cooking. They found that high levels of iron and zinc were retained through cooking and remained available for absorption in the gut following digestion. The biofortified cassava could provide 40-50 percent of Estimated Average Requirements (EAR) for iron and 60-70 percent of EAR for zinc for children and women in West Africa.
Narayanan et al 2021 Stacking disease resistance and mineral biofortification in cassava varieties to enhance yields and consumer health. Plant Biotechnology Journal https://doi.org/10.1111/pbi.13511
Okwuonu et al 2021 Opportunities and challenges for biofortification of cassava to address iron and zinc deficiency in Nigeria. Global Food Security 28, 100478, https://doi.org/10.1016/j.gfs.2020.100478.
Source: Crop Biotech Update