<i>Perilla frutescens</i> var. <i>frutescens</i> is a tetraploid plant mainly cultivated in East Asia. Interestingly, perilla oil (derived from its seed) is richer in α-linolenic acid (18:3), an important omega-3 fatty acid known for its health benefits, compared with most other plant oils for reasons thus far unexplored. In this issue, Park et al. identified two perilla mutants through gamma-ray irradiation, which affected the genes <i>PfrFAD3a</i> and <i>PfrFAD3b</i>, respectively. Knocking out both <i>PfrFAD3a</i> and <i>PfrFAD3b</i> using CRISPR/Cas9 resulted in an increase in linoleic acid (18:2) and a significant decrease in α-linolenic acid (18:3) in the seeds. This study has further revealed that the higher omega-3 fatty acid content in cultivated perilla oil is due to the presence of both <i>FAD3</i> genes, which originated from the evolution of perilla from a diploid to a tetraploid species.
The cover image shows a <i>Perilla frutescens</i> var. <i>frutescens</i> plant cultivated in a field in Jeongeup-si, Jeollabuk-do, South Korea.