Brassica juncea is grown worldwide for use in oil and mustard production. The plants naturally produce substances known as glucosinolates, which act as a defence against pests and are
known to be associated with health benefits after consumption. Pairwise used CRISPR/Cas to intervene in the metabolism of the glucosinolates and knock out specific gene functions. As a
result, the leaves should taste less pungent (Karlson et al., 2022). The number and type of genetic changes that are necessary to achieve this trait in the NGT mustard fall within the proposed EU
threshold for fast-track approvals. However, the specific genotype and phenotype are new to the environment.

This NGT intervention is associated with a reduction in compounds important to plant defence mechanisms. The NGT plants may consequently be more susceptible to plant pathogens or plant pests. Interactions with the environment may also be disturbed on several levels, thus possibly damaging other species associated with the plants (Barbour et al., 2022). Releases of
these plants may become a major problem for the ecosystems, as the plants can persist and spread in the environment and hybridise with related species. The NGT plants were deregulated by the U.S. Department of Agriculture (USDA) without detailed in-depth risk assessment. Bayer is currently trying bring these plants to market.

Publication date / last update

February 2026

Further Information:

Karlson et al., 2022: Targeted Mutagenesis of the Multicopy Myrosinase Gene Family in Allotetraploid Brassica juncea Reduces Pungency in Fresh Leaves across Environments.

Barbour MA, Kliebenstein DJ, Bascompte J. 2022: A keystone gene underlies the persistence of an experimental food web.