The chloroplast genome (plastome) of Euphorbia resinifera was sequenced using DNA extracted from 5–10 stipular spines (corresponding to approximately 20 mg of frozen tissue) from its tetragonal (rarely trigonal) stems, in order to avoid damaging the spurges by cutting the stems.
DNA libraries, prepared with the NEBNext Ultra II FS DNA Library Prep Kit (New England Biolabs), were sequenced on an Illumina NovaSeq 6000 platform (S2 flow cell). Following raw sequence trimming via Trimmomatic (v0.39) and quality control by FastQC (v0.12.1), the plastome was assembled de novo using the NOVOPlasty (v4.3.5) software, with the rbcL gene of Euphorbia ampliphylla as a seed. This assembly was comparatively validated using GetOrganelle (v1.7.7.0). Genome annotation and analysis were performed via GeSeq (v2.03) and CPGAVAS2, while OGDRAW was used to generate the standardized circular genome map.
The complete plastome of Euphorbia resinifera is a circular DNA molecule of 163,065 base pairs (bp) with a guanine-cytosine (GC) content of 35.11% and 96 SSR (Simple Sequence Repeat) loci. It exhibits the typical quadripartite structure of Angiosperms, consisting of a Large Single-Copy (LSC) region of 91,462 bp (32.06% GC), a Small Single-Copy (SSC) region of 18,285 bp (29.13% GC), and two Inverted Repeats (IR) of 26,659 bp each (42.39% GC). The analysis also details the number, nature of motifs, and distribution of these SSRs, which are key markers of genetic diversity.
The genome features a total of 132 annotated genes, including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes, distributed as follows: 82 genes in the LSC region, 12 in the SSC, and 19 in each IR region.
This study provides the first sequenced chloroplast genome among the three cactiform spurge species endemic to Morocco.
Réf. Taha A., Rabeh K., Lamara M., et al., 2026 - Complete chloroplast genome of Euphorbia resinifera: overcoming biogeographical bias in phylogenetic inference and establishing a conservation genomics framework for threatened North-West African cactiform species. Front. Plant Sci. 17:1785579. doi: 10.3389/fpls.2026.1785579
Posted by Jean-Paul Peltier.