The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) proposed on November 15, 2023, five new types of genetic modifications a plant can contain and be exempt from the regulations for the movement of organisms modified or produced through genetic engineering because such modifications could otherwise be achieved through conventional breeding methods. 88 Fed. Reg. 78285. According to APHIS’s November 14, 2023, press release, the proposed exemptions include:

• Plants that have any combination of loss-of-function modifications (modifications that reduce or eliminate a gene’s function) in one to all alleles of a single genetic locus in diploid and autopolyploid plants, or in one or both copies of a single genetic locus on up to four pairs of homoeologous chromosomes in allopolyploid plants;
• Diploid or autopolyploid plants with a single contiguous deletion of any size on one or more chromosomes;
• Autopolyploid plants containing any modification described in existing exemptions that previously applied only to diploid plants;
• Plants with up to four modifications made simultaneously or sequentially, provided that each modification individually qualifies for exemption and is at a different genetic locus; and
• Plants that have previously completed a voluntary review confirming exempt status and that have subsequently been produced, grown, and observed consistent with conventional breeding methods appropriate for the plant species, could be successively modified in accordance with the exemptions.

According to the proposed rule, the rulemaking would reduce the regulatory burden for developers of certain plants modified using genetic engineering that are not expected to pose plant pest risks greater than the plant pest risks posed by plants modified by conventional breeding methods. Comments are due December 15, 2023.