A forward genetics workflow for EMS mutagenesis, agar-based screening, and genomic analysis of Macrocystis pyrifera gametophytes

In this study we establish a proof-of-concept workflow for conducting a mutagenesis screen in Macrocystis pyrifera g ametophytes. We accomplish this by treating the gametophytes with chemical mutagen ethyl methanesulfonate (EMS), which is known to induce G > A and C > T transitions. We then culture the EMS-treated gametophytes on solid media to immobilize them for streamlined screening and strain isolation. Whole-genome sequencing identified G > A and C > T substitutions consistent with EMS mutagenesis. In this workflow, agar-based culture is used as a practical tool for immobilizing, screening, and recovering mutagenized M. pyrifera gametophytes for downstream analysis.