Plant microbiome is a very wide research area playing a major role in agriculture and plant health. This study investigates the interactions between root-associated bacterial communities and soil physico-chemical characteristics of four Moroccan desert plant species: Lavandula coronopifolia Poir. (n = 20), Lycium intricatum Boiss. (n = 20), Nitraria retusa Asch. (n = 20) and Searsia tripartita (Ucria) Moffett. (n = 20). Soil samples were collected in the rhizosphere of each plant species, and root samples from four different sites, with five random samples per site. Elemental chemical composition of soil sample was analyzed using the X-Ray fluorescence spectrometry and soil carbon, i.e., organic carbon (SOC) and inorganic carbon (SIC) were measured using the Rock–Eval® Oxypure method. Roots were assessed for their microbial community, using the 16S rDNA metabarcoding analysis. Significant variation in soil parameters was observed across sites and among the four desert plant species. SOC and SIC contents were highest in soils associated with S. tripartita, N. retusa, and Ly. intricatum, while La. coronopifolia was associated with elevated levels of Si, Al, K, and Mn. Soil EC was highest in N. retusa and S. tripartita. Microbial analysis revealed that Pseudomonadota and Actinomycetota dominated the root-associated bacterial communities, comprising around 60% of total abundance. Alpha diversity (Shannon and Simpson indices) varied significantly across species and sites, especially in La. coronopifolia. Beta diversity analyzes confirmed that geographic location significantly influenced microbial community structure. Rhizosphere network complexity and composition varied by species, with N. retusa showing broad ecological tolerance, while S. tripartita communities were strongly shaped by SOC, SIC, K, Ca, Mn, and Fe. Mantel test results further highlighted that plant identity and environmental factors differentially influence root microbial composition across sites. Each plant species showed unique responses in terms of soil characteristics and microbial communities, highlighting the importance of adopting a species-specific approach.

Lavandula coronopifolia Poir. is a medicinal evergreen shrub, wildly distributed in rocky and arid environments. It belongs to the Lamiaceae family, known by the large array of bioactive compounds it contains. Drought and salinity present major threats in arid zones and severely penalize the potential yield of naturally growing desertic plants; however, it may affect the synthesis and accumulation of their metabolites. Few studies have investigated the response of Lavandula species to abiotic stresses and to the best of our knowledge, none have been conducted on L. coronopifolia . Our study aims to investigate various responses of this species to water deficit and salt stress under controlled conditions. Two distinct experiments were conducted in a growth chamber, each lasting one month. The first one focused on water stress, with plants subjected to four water treatments: control (100% field capacity (FC)), moderate water deficit (50% FC), severe water stress (25% FC), and very severe water stress (alternating irrigation to 50% FC for one week followed by cessation of watering for the next week). These treatments were arranged in a randomized complete block design (RCBD) with 3 blocks, each containing 3 replicates per treatment, resulting in 9 replications per treatment. The second experiment investigated the effect of salt stress, where plants were exposed to four NaCl concentrations: 0, 5, 10, and 20 dS/m. This experiment was also conducted using an RCBD, with 4 blocks and 4 replicates per treatment within each block, giving a total of 16 repetitions per treatment. Growth parameters, oxidative stress indicators as well as secondary metabolite content were determined. Results have shown that under both water and salt stress conditions, plant fresh and dry weights decreased significantly. Malondialdehyde levels increased under intense stress in both experiments, indicating enhanced lipid peroxidation. Protein content increased under water stress but showed no change under salt stress. Phenolic and flavonoid contents increased with water stress but decreased with salt stress. Antioxidant activity remained stable under water stress and showed a significant increase with salt stress. These findings enhance our understanding of how plants modulate various traits in response to distinct water and salt stress conditions.

The arid climate of the Saharan regions is accentuated even more by the consequences of climate change and environmental threats, thus affecting normal plant development. The salinization of soils is one of the major stresses in the Moroccan Sahara Desert that strongly penalizes the production. In this sense, it would be interesting to explore the native flora of the target regions, and using it remains the best option to provide sustainable agriculture. The present study is part of a collaborative project with the aim of exploring desert plant species. Different parameters were taken for each species, including soil salinity and density. Two zones showed the highest levels of salinity, Daoura and Akhfennir, both in the Tarfaya province with 19.38 and 24.33 mS/cm, respectively. Although, several species were highly tolerant to salinity and were present at moderate to high densities. Among them, one can cite Aeluropus littoralis (Gouan) Parl., Halocnemum strobilaceum (Pall.) M. Bieb. and Suaeda ifniensis Caball. ex Maire.

Blue panicum ( Panicum antidotale Retz.) has been extensively studied in Southern Morocco for its ability to maintain productivity under high salinity levels. However, important knowledge gaps remain regarding crop management practices, particularly intercropping, planting density, and fertility management. Accordingly, this study evaluated, the combined effects of planting density (8 and 16 plants m ^− 2 ) and organic amendments (control, compost at 10 and 20 t ha ^− 1 , and manure at 20 and 40 t ha ^− 1 ) on the growth, physiology, mineral composition, and stress responses of blue panicum ( Panicum antidotale Retz.), under increasing saline conditions. Soil and irrigation water salinity were low (0.7 and 4.5), moderate (1.3 and 8.6), and high (7.8 and 2.8 dS m ^− 1 ), respectively. Results showed that, across sites, the highest annual biomass production was recorded under the highest density, reaching 202.5 t ha ^− 1 (fresh biomass) and 41.2 t ha ^− 1 (dry biomass). The low salinity site of Oulad Ghanem was the most productive, whereas organic amendments resulted in limited yield gains. A similar pattern was observed for stomatal conductance and chlorophyll index, which reached their highest values under low saline conditions with 393 mmol m⁻² s⁻¹ and 35, respectively. Antioxidant responses further differentiated site functioning: SOD and CAT activities increased under high salinity (72 and 9.0 U g ^− 1 FW, respectively), whereas POD peaked under moderate conditions (0.37 U g ^− 1 FW). Overall, this study demonstrates the ability of blue panicum to maintain productivity under increasing saline conditions, with organic amendments helping mitigate the adverse effect of salinity.