Search Results (35)

The typification of five names in the genus Olea (Oleaceae), viz. O. europaea subsp. cerasiformis, O. europaea var. maderensis, O. cuspidata, O. laperrinei, and O. sylvestris is discussed. These taxa are currently classified within O. europaea at the infraspecific rank. The designation of the types is based on the consultation of original material conserved in several herbaria and the literature cited in the respective protologues. The name O. europaea subsp. cerasiformis is lectotypified from a specimen preserved at FI. The name O. europaea var. maderensis (also named O. europaea subsp. maderensis or O. maderensis, and currently treated as a synonym of O. europaea subsp. cerasiformis) is lectotypified from a specimen collected by Lowe in Madeira and preserved at BM. The name O. cuspidata (currently O. europaea subsp. cuspidata) is lectotypifed from a specimen collected in India and preserved at K. The name O. laperrinei (currently O. europaea subsp. laperrinei) is lectotypifed from a specimen preserved at MPU and collected in the Sahara Desert (Ahaggar Mountains, Algeria). Finally, the name O. sylvestris (currently O. europaea var. sylvestris), wild olive, also named oleaster or acebuche (Spanish language), a wild relative of the olive tree, is lectotypified on a Miller specimen preserved at BM. Full article

Populus euphratica Oliv. serves as a keystone species in desert riparian ecosystems. Owing to its pronounced tolerance to drought and salinity, as well as its robust reproductive capacity, it has become a pioneer species in desert oases. The xyloglucan endotransglucosylase (XET)/hydrolase (XTH) gene family plays a critical role in the remodeling of plant cell walls; however, its potential biological functions in poplar remain poorly understood. In this study, we identified the XTH gene family in P. euphratica and conducted a preliminary functional analysis. A total of 33 PeXTH genes were identified, which were unevenly distributed across the chromosomes, with the highest density observed on chromosome 6. Conserved domain analysis indicated that most members contain the typical GH16 domain associated with xyloglucan endotransglucosylase activity. Phylogenetic analysis classified them into four distinct subgroups, exhibiting evolutionary conservation with the model dicot plant of Arabidopsis thaliana. Notably, the promoter analysis revealed an abundance of ABA-responsive and stress-related cis-elements, suggesting their potential involvement in response to multiple stresses. Under drought stress, PeXTH7 (PeuTF07G00088.1) exhibited a distinct expression pattern, with transcript levels significantly increasing with persistent treatment. RT-qPCR results confirmed that PeXTH7 is highly expressed in both roots and leaves. Furthermore, subcellular localization assays demonstrated that the PeXTH7 protein localizes to the secretory pathway and the cell wall, implying a role in cell wall dynamic remodeling through the regulation of xyloglucan metabolism. The PeXTH7-overexpressing transgenic lines exhibited a significant increase in root length compared to the wild-type controls. As the first systematic analysis of the XTH gene family in P. euphratica, this study fills an important knowledge gap and provides new insights into the adaptive mechanisms of desert tree species. Full article

Pistacia terebinthus L. which has been traditionally used in diet and medicine, remains underexplored in Greece, particularly regarding its chemical composition and antioxidant activity. The current study aims to comparatively evaluate the chemical profile of cold-pressed terebinth fruit oils, obtained from wild trees growing in the Greek Island of Chios (North East Aegean Sea), harvested during three years (2019, 2020 and 2021). The oils’ lipid profile was dominated by oleic acid (C18:1 cis-9) (42–45%) followed by palmitic acid (C16:0) (24–30%) and linoleic acid (C18:2 cis-9,12) (19–22%). Their phenolic acid content, expressed as anacardic acids—known for their bioactive properties—was quantified via q-¹H-NMR and found to be markedly high (1.91–2.98 mmol/kg oil). Total phenolic content (TPC) of the fruit extract showed interesting high value (185.92 ± 2.61 mg GAE/g) accompanied by strong antioxidant activity (DPPH, exhibiting > 80% inhibition at a concentration of 100 µg/mL) which was positively correlated with TPC. Additionally, the fruits demonstrated a rich nutritional profile, particularly in crude fibers (38.9%) and essential minerals (K, Mg, and Zn), along with low sodium content, suggesting notable dietary benefits. The cold-pressed oil exhibited high lipid content and low specific extinction coefficients (K₂₃₂, K₂₇₀), indicating minimal oxidation and confirming the oil’s freshness. These findings highlight the potential of P. terebinthus fruit oil as a high-value functional raw material with nutritional and antioxidant properties. Comparable to olive oil in lipid quality, Greek turpentine fruit and oil could play a promising role towards further applications in the food, cosmetic and pharmaceutical sectors. Full article

Phenolic compounds are important targets in olive breeding due to their health benefits and impact on fruit and oil quality. Fruit phenolic profiling enables efficient screening of large germplasm collections without oil extraction, but environmental variability, especially year-to-year differences, affects their expression. The aim of this study was to assess the genotypic influence on fruit phenolic composition, based on a three-year evaluation of 10 wild olive genotypes and 75 cultivars from an olive core collection. Each genotype was sampled in at least two seasons, with 1 to 3 trees analyzed annually. Variance analysis revealed significant genetic variation among cultivars and notable genotype-by-year interactions for certain phenolics. Broad-sense heritability was generally high for most compounds, although some, such as ligstroside and ligstroside aglycone, showed greater environmental sensitivity. Best linear unbiased predictions (BLUPs) were highly correlated with average relative phenotypic values. Clustering analyses identified strong associations among key phenolic compounds and highlighted distinct metabolic profiles separating wild and cultivated genotypes, reflecting differences in phenolic accumulation patterns. These findings demonstrate the genetic and environmental influences on olive fruit phenolics and provide reliable estimates to support future marker-assisted selection studies aimed at developing useful tools in olive breeding programs. Full article

This study aims to identify the optimal conditions—host, plant material, seasonality, and agricultural practices—for isolating and developing a collection of culturable endophytic microorganisms to support sustainable Olea europaea L. cultivation. Samples were collected from three Sicilian olive cultivars (‘Nocellara del Belice’, ‘Nocellara Etnea’, and ‘Nocellara Messinese’) and six wild olive accessions across different phenological phases and under organic and conventional agronomic management. Endophytes were isolated from leaves and twigs using a culture-dependent approach, and their taxonomic diversity and plant-growth-promoting (PGP) traits were analyzed. A total of 133 endophytic isolates were identified, spanning bacterial (Proteobacteria, Firmicutes, and Actinobacteria) and fungal (Ascomycota and Basidiomycota) phyla. Wild olive trees contributed more than cultivated varieties to enriching the diversity and composition of culturable endophyte collection as well as twigs instead of leaves. Winter sampling allowed to implement the taxonomic genera of olive endophyte collection. Both farming systems favored an increase in the composition of microbial collection, though organic farming systems supported greater microbial richness. Functional analysis highlighted key PGP traits in a selection of bacterial isolates, including indole-3-acetic acid and siderophore production, nitrogen fixation, and antifungal activity. Bacillus spp. dominated enzymatic activities, such as amylase, protease, and lipase production, as well as antifungal activity against the olive fungal pathogen Neofusicoccum vitifusiforme. This research highlights the significant diversity and functional potential of Mediterranean olive endophytes. Our findings emphasize the role of native microbial communities as bio-inoculants, promoting plant growth, nutrient uptake, and disease resistance. These insights lay the groundwork for developing targeted olive-microbial consortia for biocontrol and stress tolerance applications. Full article

Agricultural practices significantly influence agroecosystem biodiversity, driving a growing focus on the development of environmentally sustainable management strategies. Olive (Olea europaea L.) is one of the most widely cultivated tree crops in the Mediterranean basin and other regions with a Mediterranean climate. In this study, we employed a split-plot design with whole plots arranged as a randomized complete block design (RCBD) to evaluate the effects of minimum tillage and the application of wood distillate to olive canopies on wild vascular plant and soil-dwelling springtail communities in a conventionally managed olive grove in central Italy. Biotic communities were sampled twice, in November and April. Tillage caused a marginally significant decrease in springtail species richness in April and significantly influenced the composition of both plant and springtail communities in April. All the plant species showed a decrease in abundance under tillage, whereas the abundance of springtail species responded to tillage in a species-specific way. Wood distillate had no effect on any community attribute in either season. Springtail total abundance was not affected by any treatment in either season. Our findings confirm that tillage practices affect the diversity of plant and springtail communities. Moreover, we had evidence that spring tillage may have more negative impacts on the studied communities with respect to autumn tillage. Moreover, we suggest that the application of low-concentration wood distillate to olive canopies can be considered, in the short-term, a sustainable agricultural practice that does not negatively affect agroecosystem biodiversity. Full article

Emerald ash borer (EAB, Agrilus planipennis Fairmaire) is an Asian woodborer that is a destructive pest of ash (Fraxinus spp.) trees throughout North America and in parts of Asia and Europe. It has killed hundreds of millions of ash trees worldwide in the past two decades and has shown some ability to infest novel hosts, most notably white fringetree (Chionanthus virginicus L.). Here, I review the evidence that this beetle can succeed on cultivated olive (Olea europaea L), a close relative of white fringetree. Studies and observations thus far indicate that, while young trees are largely resistant to EAB larval development, adults will oviposit on olive trees, can feed on their foliage and produce viable eggs, and that larger, older and possibly stressed trees have the potential to support larval development to the adult stage in the field. Emerald ash borer will soon interact with cultivated olive trees in the wild in parts of the U.S. and in Europe, and the realized risk to olives by this beetle will be revealed. Full article

Biofilms represent complex three-dimensional microbial communities that can harbor strains highly resistant to antimicrobial agents. These structures, which form on both biotic and abiotic surfaces, are associated with food spoilage and increased complications in hospitalized patients. Consequently, there is significant interest in developing novel biofilm and infection control strategies, particularly those focusing on natural molecules with dual antimicrobial and antibiofilm properties. In this study, olive tree twigs from three varieties of Olea europea chemlal (CH), Azeradj (AZ), and wild-type Olea europaea sylvestris (W) were collected from the Kabylia region in Algeria. The samples underwent systematic extraction and were evaluated for their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, antimicrobial properties via disk diffusion assay, minimum inhibitory concentration (MIC), and antibiofilm capabilities. Results demonstrated that olive tree twig extracts exhibited substantial antioxidant activity and significant antibacterial and antibiofilm potential. The antioxidant activity, measured through DPPH radical scavenging, showed IC50 values ranging from 38.12 ± 1.52 µg/mL to 148.7 ± 1.23 µg/mL. When tested against six pathogenic bacterial strains, including both ATCC reference strains and milk isolates, the MIC values ranged from 1.18 mg/mL to 4.71 mg/mL. Notably, sub-inhibitory concentrations significantly reduced biofilm formation across most tested strains, with inhibition rates varying from 21% to 90.43%. The effectiveness of biofilm inhibition was dependent on the bacterial strain, olive tree variety, and extract concentration used. Statistical analysis confirmed the significance of these results (p < 0.05). Given the demonstrated antioxidant, antibacterial, and antibiofilm properties of these olive tree twig extracts, they show promise for further development as surface disinfectants and potential applications in food safety and infection control. Additional research is warranted to fully characterize their mechanisms of action and optimize their practical applications. Full article

While olive trees are primarily wind-pollinated, biodiversity-friendly management of the groves can contribute to the conservation of pollinating insects in olive agroecosystems. Previous research demonstrated that semi-natural habitats, such as herbaceous linear elements and woody areas, support the community of pollinators in agroecosystems. Less is known about the contribution of low-input olive groves with a permanent ground cover on terraced landscapes. This study investigated the relationship between pollinator communities and semi-natural habitats, including spontaneous vegetation, in a traditional terraced Mediterranean olive grove agroecosystem. The research employed pan traps to monitor wild bees and observation walks to assess the butterfly community across three different habitat types in spring, summer, and autumn during two growing seasons. Floral resources in the habitats were assessed during each sampling time. Analysis showed that herbaceous habitats support a higher abundance of wild bees than woody areas, while olive groves do not differ significantly from either habitat type, despite exhibiting the highest floral abundance. This suggests that habitat structure, rather than floral availability alone, plays a role in maintaining the wild bee community. For butterflies, results demonstrate that the overall abundance does not differ between habitats, while the species composition does. The study emphasizes the importance of preserving diverse habitats, and in particular low-input olive groves, within agricultural landscapes to support a wide range of pollinator species. Full article

(1) Background: Human–wildlife conflict can lead to adverse consequences for both parties, particularly in areas with a high concentration of wild ungulates. Ungulates cause frequent, severe plant damage by stripping the bark or browsing on the youngest plants. In the latter case, they damage vegetative sprouts and leaves, which can cause a delay in growth or the plant’s death. Tuscany is notable for its significant population of wild boar, which cause substantial damage to vineyards and cereal crops, costing farmers millions annually. In Tuscany, given the highly cultivated landscape of olive trees, damage has also been recorded in these plants. Balancing human and wildlife needs is crucial for minimizing damage and ensuring coexistence. (2) Methods: This study tested innovative electronic playback devices using long-range radio technology (LoRa) to deter wild ungulates and prevent crop damage. These devices use sounds and lights to induce wild animals to be afraid and thus run away from the cultivated plot to be protected. The experiment was conducted on a farm in Chianti, Tuscany, involving four plots of land planted with olive trees: in two test areas, four playback devices and four camera traps were installed, and in the two control areas, only camera traps were installed. Playback devices aimed to deter wild ungulates and camera traps aimed to test their effectiveness. Data from the camera traps were analyzed statistically and behaviorally. (3) Results: Playback devices significantly reduced wild animal activity in the equipped areas. Statistical analysis revealed that the use of acoustic–luminous deterrent devices (PDs) significantly reduced wildlife visits to the olive groves. (4) Conclusion: The study’s findings, supported by heatmaps and frequency analyses, provide insights into wildlife activity patterns and guide the development of targeted, effective wildlife management strategies. Full article

Populus euphratica Oliv. typically has four kinds of heteromorphic leaves: linear (Li), lanceolate (La), ovate (Ov) and broad ovate (Bo). Heteromorphic leaves help P. euphratica adapt to extreme desert environments and further contribute to protection against land desertification in Northwest China. In the authors’ previous research, growth-regulating factors (GRFs) were speculated to be related to the development of P. euphratica heteromorphic leaves via multi-omics integrated analysis. However, the genomic features and biological role of the P. euphratica GRF gene family in heteromorphic leaves are still unclear. In this study, 19 PeGRF genes were genome-widely identified and characterized in P. euphratica, and their physicochemical properties, gene structure and phylogenetic evolution were analyzed. An analysis of the research showed that PeGRFs were unevenly distributed on 11 chromosomes and that PeGRF proteins contained conserved motif 1 (WRC) and motif 2 (QLQ). Moreover, 19, 15, 19 and 22 GRFs were identified in Populus deltoides Marshall, Populus pruinosa Schrenk, Salix sinopurpurea C. Wang et C. Y. Yang and Salix suchowensis W. C. Cheng, respectively. A collinearity analysis showed that the PeGRF family evolved slowly within Populus species. A phylogenetic tree of the GRF family was also constructed, and GRFs were divided into four subfamilies. A large number of cis-acting elements were related to plant growth and development, plant hormone response and stress response on the promoter of PeGRFs. The expression pattern of PeGRFs showed significant up-regulation in broad leaves (Ov and Bo) compared with narrow leaves (Li and La). In combination with the predicted gene regulatory network, PeGRF9 (PeuTF06G01147.1) may have an important contribution to the leaf shape development of P. euphratica. The heterologous expression of PeGRF9 in wild-type plants (Col-0) of Arabidopsis thaliana (L.) Heynh was also studied, showing a significant increase in the leaf area of overexpressing plants compared with the wild type. Nineteen PeGRF gene members were identified and characterized in P. euphratica, and a comparison of the genomic analysis of Populus GRF members revealed their evolutionary features. The further overexpression of PeGRF9 in A. thaliana revealed its biological role in the heteromorphic leaves of P. euphratica. This study not only provides new insights into the evolution and function of PeGRFs in P. euphratica heteromorphic leaves but also helps in an understanding of the adaptive evolution of P. euphratica in drought desert environments. Full article

Wild olive tree, or oleaster (var. sylvestris), native to the Mediterranean region, is considered a traditional source of healthy food. Wild olive fruit (WOF) exhibits several biological properties associated with its chemical composition. Although Greece has important olive genetic resources, including oleaster populations, limited information is available on the chemical characterization of WOF. Therefore, the present investigation was undertaken to study the nutritional, bioactive (phenolics, tocopherols, and pigments), volatile profile, and antioxidant properties of WOF collected from Greece. Moreover, eco-friendly processes, including ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and accelerated solvent extraction (ASE), were applied to obtain oleuropein-rich extracts from WOF. Evaluation of phenolic composition in WOF extracts was carried out by LC-DAD-ESI-MS, while antioxidant activity was evaluated by applying DPPH, ABTS, and FRAP methods. Our outcomes show that Greek WOF is rich in oleic acid (71.55%), total phenolics (64.89 mg GAE/g dw), tocopherols (107.05 mg/kg dw), and carotenoids (85.90 mg/kg dw). Oleuropein (72.03 mg/g dw) was the main phenolic compound in the WOF extracts. Also, the WOF was characterized by an increased level of volatile compounds, mainly terpenoids (46.73%). UAE was more efficient than MAE and ASE for recovering oleuropein-rich extracts with high antioxidant activity. These results emphasized the high potential of WOF as an alternative bioactive ingredient for use in the food industry. Full article

The genetic diversity of the ancient autochthonous olive trees on the Maltese islands and the relationship with the wild forms growing in marginal areas of the island (57 samples), as well as with the most widespread cultivars in the Mediterranean region (150 references), were investigated by genetic analysis with 10 SSR markers. The analysis revealed a high genetic diversity of Maltese germplasm, totaling 84 alleles and a Shannon information index (I) of 1.08. All samples from the upper and the lower part of the crown of the Bidni trees belonged to the same genotype, suggesting that there was no secondary top-grafting of the branches. The Bidni trees showed close relationships with the local wild germplasm, suggesting that the oleaster population played a role in the selection of the Bidni variety. Genetic similarities were also found between Maltese cultivars and several Italian varieties including accessions putatively resistant to the bacterium Xylella fastidiosa, which has recently emerged in the Apulia region (Italy) and has caused severe epidemics on olive trees over the last decade. Full article

Glaucoma is characterized by cupping of the optic disc, apoptotic degeneration of retinal ganglion cells (RGCs) and their axons, and thinning of the retinal nerve fiber layer, with patchy loss of vision. Elevated intraocular pressure (IOP) is a major risk factor for hypertensive glaucoma and the only modifiable one. There is a need to find novel compounds that counteract other risk factors contributing to RGC degeneration. The oil derived from the wild olive tree (Olea europaea var. sylvestris), also called Acebuche (ACE), shows powerful anti-inflammatory, antioxidant and retinoprotective effects. We evaluated whether ACE oil could counteract glaucoma-related detrimental effects. To this aim, we fed mice either a regular or an ACE oil-enriched diet and then induced IOP elevation through intraocular injection of methylcellulose. An ACE oil-enriched diet suppressed glaucoma-dependent retinal glia reactivity and inflammation. The redox status of the glaucomatous retinas was restored to a control-like situation, and ischemia was alleviated by an ACE oil-enriched diet. Notably, retinal apoptosis was suppressed in the glaucomatous animals fed ACE oil. Furthermore, as shown by electroretinogram analyses, RGC electrophysiological functions were almost completely preserved by the ACE oil-enriched diet. These ameliorative effects were IOP-independent and might depend on ACE oil’s peculiar composition. Although additional studies are needed, nutritional supplementation with ACE oil might represent an adjuvant in the management of glaucoma. Full article

Eucommia ulmoides Oliver is a unique tertiary relict tree species in China belonging to the Eucommia family and genus. It is a traditional and precious Chinese medicinal herb with anti-tumor, antibacterial, antioxidant, anti-inflammatory, and bidirectional blood pressure regulation effects. Eucommia ulmoides mainly grows in temperate regions of China, but due to its sensitivity to low-temperatures, it is difficult to introduce into new regions. To study the role of Eucommia ulmoides lipocalin in plants. This investigation was conducted utilizing gene cloning, bioinformatics analysis, quantitative real-time polymerase chain reaction (qRT-PCR), subcellular localization, and stable genetic transformation to transfer EuTIL1 into Nicotiana tabacum Xanthi. The wild-type transgenic vector and EuTIL1 tobacco were cold-treated, and the corresponding protective enzyme activity and cold-induced gene expression levels were measured to analyze the functions of the genes. In this study, the full-length of the temperature-induced lipocalin gene (EuTIL1) cDNA was cloned from the leaves of Eucommia ulmoides using the rapid amplification of cDNA ends (RACE) method. The sequence analysis showed that the full-length cDNA of EuTIL1 was 917 bp and encodes a protein of 188 aa residues, which is a member of the Lipocalin-2 family. Subcellular localization analysis revealed that EuTIL1 was found in the plasma membrane. The transgenic tobacco lines expressing EuTIL1 under the control of the CaMV 35S promoter had increased tolerance to cold compared to wild-type (WT) plants. The average water loss rate of EuTIL1 transgenic plants was 12.4%, the average conductivity at 24 h was 55.11%, and the malondialdehyde content at 24 h was significantly lower than that of wild-type plants. The maximum soluble sugar (SS) content, superoxide dismutase (SOD) activity, peroxidase (POD) activity, and catalase activity of EuTIL1 plants after low-temperature treatment were 22.03 mg/g, 726.87 U/g, 1283.94 U/g, and 356.84 U/g, respectively, which are significantly higher than those of the wild-type. Meanwhile, in the EuTIL1 transgenic tobacco plants, the expression of the NtDREB1, NtDREB2, NtDREB4, and NtCOR15a elevated under the low-temperature treatment condition. In conclusion, our study demonstrates that EuTIL1 is a gene involved in the cold-stress response and has the potential to enhance cold tolerance in plants, providing a potential molecular basis for the study of Eucommia ulmoides introduction and serving as a candidate gene for evaluating cold-tolerant plants. Full article