Argania spinosa Genome Annotation

Argania spinosa (L. Skeels), a key oil-producing tree endemic to Morocco, has major ecological and economic importance but remains under-represented in genomic databases. Previous efforts to assemble and annotate the genome have provided limited insights into non-coding regions and secondary metabolism pathways. Here, we present an enhanced nuclear genome annotation of A. spinosa, which was assembled from high-coverage Illumina reads and scaffolded to 690 Mbp in size. Structural annotation via AUGUSTUS, trained on three plant models, Arabidopsis thaliana, Olea europaea, and Camellia sinensis, predicted protein-coding genes. Functional annotation via EggNOG-mapper and PMN-based BLAST alignments identified over orthologous groups involved in oil and tocopherol biosynthesis, substantially expanding beyond prior datasets. Moreover, we identified non-coding RNA loci, including long non-coding RNAs and miRNAs, that were previously uncharacterized in A. spinosa. Repeat content analysis revealed that 55% of the genome comprised transposable elements, with a dominance of LTR retrotransposons, supporting genome expansion via repeat proliferation. These new genomic resources offer a more complete understanding of the metabolic, regulatory, and structural complexity of A. spinosa and provide a foundation for breeding, biotechnological valorization, and conservation of this iconic species.