This synthesis summarizes current knowledge about the microorganisms (bacteria, fungi, and yeasts) living in association with the argan tree and highlights their key roles in the tree’s health and its environment, both in natural settings and nurseries.
The Players in the Argan Tree Microbiome
Bacteria: Some, known as PGPR (Plant Growth-Promoting Rhizobacteria), are dominated by the genus Streptomyces. They help the argan tree absorb phosphorus (an essential nutrient) from the soil, regulate its hormones for better growth, combat diseases (biocontrol), and produce useful compounds for industry, such as eco-friendly alternatives to plastics (polyhydroxybutyrate).
Fungal Communities: Dominated by arbuscular mycorrhizal fungi (symbiotic fungi associated with roots), which improve phosphorus absorption and help the tree resist drought. They also include endophytic Ascomycetes, a source of bioactive compounds (antioxidants, antifungals), and entomopathogenic fungi that protect the argan tree from harmful insects (biocontrol).
Yeasts: Although less documented, they may possess unexplored metabolic traits with applications in agro-food processes (texturizers, emulsifiers, flavors) and biotechnology.
The study also emphasizes that the perception of microbial diversity is strongly influenced by both the isolation environment and identification methods, ranging from culture-based techniques to high-throughput sequencing and metagenomics.
It concludes that understanding the argan tree microbiome offers major prospects for the sustainable restoration of argan forests, the development of climate-resilient agriculture, and biotechnological innovation.
Réf. Taqarort N., Sadik S., Bouharroud R. & Qessaoui R. 2026 - Microbial diversity associated with the argan tree and its functional and biotechnological potential. Discover Plants (2026) 3:89 https://doi.org/10.1007/s44372-026-00571-7
Posted by Jean-Paul Peltier.
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.
Argan orchards (aged 2 to 10 years) managed under extensive systems in the Arganeraie Biosphere Reserve were studied to assess carbon stocks in the main ecosystem components (aboveground argan tree biomass, leaf litter, herbaceous vegetation, and soil). The study, conducted across six sites between 2021 and 2023, combined morpho-physiological and dendrometric measurements with structural equation modeling to analyze interactions among compartments. Carbon stocks were estimated according to IPCC guidelines (2006, revised in 2019).
The results show an increase in carbon stock in argan tree biomass with age (from 0.003 to 1.938 t C ha⁻¹ between 2 and 10 years). Contributions from litter (0.36–8.51 kg C ha⁻¹) and herbaceous biomass (0–0.56 t C ha⁻¹) remain limited. Soil constitutes the main carbon reservoir, with stocks ranging from 10.12 to 80.5 t C ha⁻¹ (0–30 cm) and from 8.49 to 75.94 t C ha⁻¹ (30–60 cm).
These results highlight the dominant role of soil in carbon sequestration and emphasize the potential of extensive arganiculture for ecosystem restoration and climate change mitigation. They also confirm the relevance of integrating these systems into national climate strategies and carbon valuation mechanisms, particularly in arid regions.
Ref. Oumasst A., Tiouidji F. E., Chabbi N., et al. 2026 - Evaluating the dynamics of carbon accumulation in extensive argan orchard ecosystems in arid regions. Ecological Processes (2026) 15:6 - https://doi.org/10.1186/s13717-025-00666-1
Posted by Jean-Paul Peltier.
The study aims to map, using very high spatial resolution satellite imagery, the argan tree formation located in the upper valley of Oued Grou. This stand corresponds to a disjunct population located about 400 km north of the main distribution range of the argan tree. It is considered a site of biological and ecological interest and has been identified as a priority for the implementation of conservation and enhancement measures.
The study area is characterized by a semi-arid bioclimate with mild winters, with annual precipitation estimated between 400 and 450 mm.
Overall, the argan grove appears as a degraded matorral resulting from the combined effects of wood cutting and overgrazing. It includes approximately 775 argan trees scattered over a 1,200 ha area with a silvo-pastoral vocation, located between 200 and 600 m above sea level.
Most of the argan trees grow on very steep slopes exposed to the south or southwest, on Paleozoic schist substrates characterized by poorly developed soils. In these areas, argan trees are mainly associated with five-leaved sumac (Rhus pentaphylla).
A few individuals are also observed on north-facing slopes. However, on these slopes, where soils are generally deeper and better developed, the dominant vegetation formation corresponds to woodlands of thuya (Tetraclinis articulata), wild olive (Olea europaea subsp. europaea), and mastic tree (Pistacia lentiscus).
To date, this site has never been subject to a management plan. This absence of management measures partly explains the degree of degradation observed, with nearly 68% of the area currently occupied by bare soils.
It should be recalled that the presence of the argan tree in the Oued Grou valley was first reported by Emberger in 1924. Furthermore, the study of the chloroplast genome of the argan tree has shown that these stands likely result from a relatively recent dispersal, probably of anthropogenic origin (El Mousadik & Petit, 1996).
Ref. Sahel Y., Dellahi Y. & Chahhou D., 2022 - Mapping the Site of Biological and Ecological Interest of Rganat-Bouchkal (Tsili) Argan forest (Moroccan Central Plateau) using remote sensing. IOP Conf. Ser.: Earth Environ. Sci. 1090 012001
Posted by Jean-Paul Peltier.
This study presents a bibliometric analysis of 926 scientific publications devoted to Argania spinosa, extracted from the Scopus database and covering the period 1897–2024. It constitutes the first investigation encompassing all research themes related to the argan tree. The selection of the corpus and the search strategy were carried out according to the PRISMA 2020 guidelines.
The methodological approach relies on the use of the Bibliometrix package and the VOSviewer software, which since the late 2010s have become reference tools for evaluating scientific performance, analyzing collaboration networks, and visualizing keyword co-occurrences.
The earliest writings on the argan tree date back to the 12th century and are attributed to Andalusian Arab scholars, but scientific research remained limited until the 1990s. Between 1996 and 2021, scientific output increased progressively, in connection with the development of the argan oil sector and its economic valorization, particularly in medicine, phytotherapy, and cosmetics. This dynamic can also be explained by the creation of women’s cooperatives, international development programs, various certifications (UNESCO biosphere reserve, intangible cultural heritage), the strengthening of public policies, the contribution of national and international funding, and the organization of scientific conferences. Industrial interest and international demand have stimulated research on the chemistry, genetics, domestication, and biological properties of the argan tree. However, the period 2021–2024 shows a recent decline in publications, probably related to the effects of the COVID-19 pandemic, financial constraints, and unfavorable climatic conditions.
Network analyses highlight the intellectual and social structure of the research field (authors, domains, sources, countries, and collaborations).
The co-occurrence analysis of eighty-eight emerging keywords identifies two major thematic clusters. The first concerns research on argan oil: chemical composition, extraction techniques, the role of phenolic compounds in tolerance to water stress, variation of fatty acids and phenolic compounds among argan tree varieties, as well as antioxidant properties and effects on human health. The second cluster deals with the conservation and reforestation of argan forests and their adaptation to climate change. Publications address conservation initiatives, plantations, genetic diversity, germination techniques, and the valorization of by-products such as argan shells.
The cross-analysis of conceptual, intellectual, and social structures provides a contextualized interpretation of the evolution of research and helps better understand the dynamics and orientations of the scientific community working on the argan tree.
Today, research remains mainly oriented toward the valorization of argan oil, while long-term forest sustainability remains relatively understudied in the context of climate change. Future research should adopt a multidisciplinary approach integrating genomics, biotechnology, nursery innovation, molecular genetics, digital monitoring tools, and socio-institutional governance.
Among the strategies proposed to strengthen the resilience of argan forests is assisted migration, which involves intentionally relocating the species to areas less affected by climate change. However, this approach overlooks the fact that the argan forest also constitutes a cultural landscape, reflecting a long-standing and close relationship between local populations and their environment.
The originality of this publication lies in the construction of the corpus, the depth of the analysis, and the scientific interpretation of the results.
Ref. Timzioura R., Ezzine S., Benomar L., et al., 2025 - Bibliometric Analysis of Argan (Argania spinosa (L.) Skeels) Research: Scientific Trends and Strategic Directions for Climate-Resilient Ecosystem Management. Forests, 16, 892. https://doi.org/10.3390/f16060892
Posted by Jean-Paul Peltier.
Last modified on Monday, June 22, 2026 at 10h24.