A mutation in a gene called GPAT1 in Arabidopsis plants makes them taller but reduces seed oil production. The GPAT1 gene is important for making oils in plants and is usually found in flowers, seed pods, and seeds. When GPAT1 is not working properly, plants grow taller by making their cells longer. This happens because the gene affects the production of a plant hormone called gibberellin, which helps cells grow. Even though the plants get taller, they produce fewer seeds because the gene mutation affects how oils are made in the seeds. This study shows how a gene involved in making oils in plants also affects how tall they grow by changing how cells grow.