Detailed Characterization of Ovule and Seed Development in Camelina sativa Reveals a Conserved DELLA–GAI Pathway for Seed Size

Camelina sativa , commonly known as false flax, is an ancient oilseed crop that is gaining attention for its potential as a sustainable biofuel source and supplier of valuable bioactive compounds. With its ability to grow in diverse climates and marginal soils, Camelina exhibits high resilience to environmental stress factors, making it an attractive option for cultivation in areas unsuitable for conventional crops. Driven by these positive attributes and renewing interest, research into the agronomic potential, genetic diversity, and biotechnological applications of Camelina has increased substantially in recent years. Most of these studies focus on improving seed fatty acid profile, mostly through gene editing using the CRISPR technology, while maintaining seed viability. Strikingly, detailed characterization of seed development in Camelina is missing, which complicates the design of biotechnological interventions at specific developmental stages and the evaluation of potential modifications resulting from editing key developmental genes. In this work, we fill this gap by providing a detailed characterization of seed development in wild type Camelina plants, from ovule initiation to full seed maturity. Attention is given to the differences between Camelina and the reference plant Arabidopsis. Through transgenic analysis, we further show that the stabilization of GAI in Camelina ovules induced an increase in seed size, consistent with observations in Arabidopsis. These findings reveal a high degree of regulatory and functional conservation of DELLA factors between these two species. • Camelina ovule and seed development strongly resembles Arabidopsis model species • Camelina ovules have an extra inner integument cell layer compared with Arabidopsis • The stable version of the Arabidopsis GAI protein increases seed size in Camelina • Arabidopsis GAI regulatory sequences drive conserved spatial expression in Camelina