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Cistus crispus (Cistaceae) is a species adapted to arid and semi-arid conditions, and it has ornamental and medicinal uses. In Italy, native populations of C. crispus are threatened by the collection due to the low number of individuals in the populations, anthropogenic pressure, and the changing environmental condition that enhance other more aggressive and hybridisable Cistus species. Here, we set up the variables for its micropropagation protocols to achieve a high number of plants per unit time. Various steps of the micropropagation protocol were modulated, including various sodium hypochlorite concentrations (CHCs) and time of sterilisation. The efficiency of the protocol maximised at 25 min sterilisation with 2.5% CHC and decreasing explant vitality at increasing time and CHC. Both shoot proliferation and root emissions were maximised at 1.78 μM N-6-benzyladenine (BA) in the growing medium, with up to 5.4 explants per cycle, with 5.8 roots per explant, and 84 healthy explants. Kinetin stimulated further the axillary root proliferation more than dimethylallylamino purine or BA. Lastly, the application of indole acetic acid increased root emissions during the acclimation stage more than the application of indole butyric acid, and this occurred irrespective of their concentrations, up to 2.0 μg · g−1. These results can foster the use of C. crispus as an ornamental species, for xeriscaping or for the extraction of its secondary compounds, which have various industrial uses. These results can also have an indirect implication for the conservation of the species by reducing the collection for ornamental purposes from its natural population.

St John’s Wort (Hypericum perforatum L.; Hypericaceae) is a perennial medicinal herb widespread and largely used in folk medicine inside the Mediterranean basin. Many bioactive compounds have been identified within its extracts. Under a pharmacological point of view, the most important of them belong to the chemical classes of naphthodianthrones, phloroglucinols and polyphenols. Many factors have been claimed responsible for the phytochemical variability in Hypericum perforatum, such as genotype, geographical origin, harvesting stage and age of the plants. Yet, when harvested plant material is addressed to the industry, the standardization of the active ingredients over cultivation years is a crucial issue. With the aim to detect the stability over years and genotypes of several bioactive Hypericum compounds, seven Hypericum biotypes retrieved from different Italian geographical areas were cultivated in 2015 and 2016, and their aerial flowering parts were analyzed. Naphthodianthrones (hypericin and its biosynthetic precursors), phloroglucinols (hyperforin and adhyperforin), and main polyphenols were determined by HPLC-DAD analysis. The results were statistically evaluated through ANOVA, and the stability over cultivation years of the tested genotypes was assessed. In rather all the examined metabolites, the ANOVA revealed a remarkable effect of both factors “year” (Y) and “provenance” (P), but the occurrence of significant “Y x P” interactions evidenced that the effect of climatic variability was often different according to the genotype. The evaluation of the stability level between years evidenced that only one biotype out of seven exhibited constantly higher-than-average amounts of rather all identified metabolites.

DNA barcoding is a well-known technique that enable species identification by using universal DNA sequences from a small fragment of the genome. In this work, the effectiveness of DNA barcoding approach was evaluated in order to identify different taxonomic groups among two families (Arecaceae and Fabaceae) from two flowering plant collections: some were economically important taxa from nursery production and Mediterranean plants with ornamental attitude for possible new introduction. Three chloroplast DNA barcode regions (matK, rbcL and trnH-psbA) proposed by the Consortium for the Barcode of Life (CBOL) were tested in 22 Arecaceae species and in eight Fabaceae species, including Ceratonia siliqua. The greatest success of discrimination was found in the Fabaceae in which all eight taxa were unambiguously identified, while in the Arecaceae, only seven out of 22 taxa were discriminated at the species level. The matK marker gave the lowest values of genetic divergence (GD) for the Arecaceae (1.5%) and the highest for Fabaceae (GD=6.4%); the rbcL marker was not particularly informative in the Arecaceae (GD=0.7%), as well as the TrnH-psbA (GD=2.9%). TrnH-psbA presented high variability values in the Fabaceae (GD=7.4%), while rbcL marker showed modest differences (GD=1.5%). Although additional markers or different primer combinations are needed for a better discrimination of the Arecaceae, our results confirmed the potential of the barcoding approach for quick identification of Mediterranean plant species. Data of taxa discriminated at the species level with the DNA barcoding methodology will be included in the database and can be used for traceability purpose to protect both the biodiversity and the economic interest of companies and end-users.

Leaves of Aloe arborescens Mill. are a relevant source of secondary metabolites of pharmaceutical relevance. Notwithstanding, specialized cultivations of A. arborescens are still rather limited, and a straightforward agronomical research addressed to the obtainment of high-quality material is lacking. With the purpose to fill this gap, from 2016 to 2018, a trial was arranged to evaluate the growth and development of A. arborescens, along with the production of four active metabolites (aloin A and B, aloenin A, and isoaloeresin D) with varying some growth conditions. Two growth substrates (“A”- a commercial substrate, and “B”- the same substrate + 20 % perlite), two durations of pre-transplant open-air storage (“stress”, 7 and 14 days), and 3 illumination levels obtained by means of shadow nets with different mesh dimensions (SL: full sunlight; T50: 50 % shading; T70: 70 % shading) were tested, combined in a factorial experimental layout with 3 repetitions. In general, light intensity was the most crucial experimental factor, whereas the effects of growth substrate and pre-transplant stress were scarce and limited in time. The addition of perlite to the growth substrate gave the best results in terms of leaf size and root growth, without any significant effect on the yield of active metabolites. The increasing shading level caused a parallel increase of several biometrical characters of plants (height, number of leaves per plant and mean diameter of the stem), whereas the number of suckers per plant was positively affected by the increase of illumination level. The illumination level was also responsible for significant variations in the content of all secondary metabolites, except for aloin A, that resulted statistically not different among the illumination treatments (from 0.80 to 0.98 % in dry matter). The content of aloenin A and aloin B was higher in the plants exposed in full sun, statistically well differentiated from those exposed to 70 % shadow (2.0 vs. 1.4 % d.m. aloenin A, and 1.12 vs 0.86 % d.m. aloin B, in full sun and 70 % shadow, respectively). Contrastingly, the highest levels of isoaloeresin D were reached in the two shaded treatments (4.98 % in 50 % shadow and 4.89 % in 70 % shadow), whereas the full sun treatment reached the lowest value. The higher number of leaves in plants exposed at reduced illumination, however, brought to increased total amounts per plant of aloin (A and B) and aloenin A with increasing shadow levels.

Many aspects concerning the role of arbuscular mycorrhizal (AM) fungi in plant nutrient uptake from organic sources remain unclear. Here, we investigated the contribution of AM symbiosis to N and P uptake by durum wheat after the addition of a high C:N biomass to a P-limited soil. Plants were grown in pots in the presence or absence of a multispecies AM inoculum, with (Org) or without (Ctr) the addition of 15N-labelled organic matter (OM). A further treatment, in which 15N was applied in mineral form (Ctr+N) in the same amount as that supplied in the Org treatment, was also included. Inoculation with AM had positive effects on plant growth in both control treatments (Ctr and Ctr+N), mainly linked to an increase in plant P uptake. The addition of OM, increasing the P available in the soil for the plants, resulted in a marked decrease in the contribution of AM symbiosis to plant growth and nutrient uptake, although the percentage of mycorrhization was higher in the Org treatment than in the controls. In addition, mycorrhization drastically reduced the recovery of 15N from the OM added to the soil whereas it slightly increased the N recovery from the mineral fertiliser. This suggests that plants and AM fungi probably exert a differential competition for different sources of N available in the soil. On the whole, our results provide a contribution to a better understanding of the conditions under which AM fungi can play an effective role in mitigating the negative effects of nutritional stresses in plants. Supplementary Information The online version contains supplementary material available at 10.1007/s00572-021-01031-8.

Cannabis is an annual plant with a long history of use as food, feed, fiber, oil, medicine, and narcotics. Despite realizing its true value, it has not yet found its true place. Cannabis has had a long history with many ups and downs, and now it is our turn to promote it. Cannabis contains approximately 600 identified and many yet unidentified potentially useful compounds. Cannabinoids, phenolic compounds, terpenoids, and alkaloids are some of the secondary metabolites present in cannabis. However, among a plethora of unique chemical compounds found in this plant, the most important ones are phytocannabinoids (PCs). Over hundreds of 21-22-carbon compounds exclusively produce in cannabis glandular hairs through either polyketide and or deoxyxylulose phosphate/methylerythritol phosphate (DOXP/MEP) pathways. Trans-Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) are those that first come to mind while talking about cannabis. Nevertheless, despite the low concentration, cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabinodiol (CBND), and cannabinidiol (CBDL) may have potentially some medical effects. PCs and endocannabinoids (ECs) mediate their effects mainly through CB1 and CB2 receptors. Despite all concerns regarding cannabis, nobody can ignore the use of cannabinoids as promising tonic, analgesic, antipyretic, antiemetic, anti-inflammatory, anti-epileptic, anticancer agents, which are effective for pain relief, depression, anxiety, sleep disorders, nausea and vomiting, multiple sclerosis, cardiovascular disorders, and appetite stimulation. The scientific community and public society have now increasingly accepted cannabis specifically hemp as much more than a recreational drug. There are growing demands for cannabinoids, mainly CBD, with many diverse therapeutic and nutritional properties in veterinary or human medicine. The main objective of this review article is to historically summarize findings concerning cannabinoids, mainly THC and CBD, towards putting these valuable compounds into food, feed and health baskets and current and future trends in the consumption of products derived from cannabis.

The present study aimed at identifying and mapping key genes expressed in root tissues involved in drought and salinity tolerance/resistance conserved among different fruit tree species. Twenty-six RNA-Seq samples were analyzed from six published studies in five plant species (Olea europaea, Vitis riparia Michx, Prunus mahaleb, Prunus persica, Phoenix dactylifera). This meta-analysis used a bioinformatic pipeline identifying 750 genes that were commonly modulated in three salinity studies and 683 genes that were commonly regulated among three drought studies, implying their conserved role in resistance/tolerance/response to these environmental stresses. A comparison was done on the genes that were in common among both salinity and drought resulted in 82 genes, of which 39 were commonly regulated with the same trend of expression (23 were upregulated and 16 were downregulated). Gene set enrichment and pathway analysis pointed out that pathways encoding regulation of defense response, drug transmembrane transport, and metal ion binding are general key molecular responses to these two abiotic stress responses. Furthermore, hormonal molecular crosstalk plays an essential role in the fine-tuning of plant responses to drought and salinity. Drought and salinity induced a different molecular &ldquo, hormonal fingerprint&rdquo, Dehydration stress specifically enhanced multiple genes responsive to abscisic acid, gibberellin, brassinosteroids, and the ethylene-activated signaling pathway. Salt stress mostly repressed genes encoding for key enzymes in signaling proteins in auxin-, gibberellin-(gibberellin 2 oxidase 8), and abscisic acid-related pathways (aldehyde oxidase 4, abscisic acid-responsive element-binding protein 3). Abiotic stress-related genes were mapped into the chromosome to identify molecular markers usable for the improvement of these complex quantitative traits. This meta-analysis identified genes that serve as potential targets to develop cultivars with enhanced drought and salinity resistance and/or tolerance across different fruit tree crops in a biotechnological sustainable way.

The alteration of heavy (&ldquo, ON/bearing&rdquo, ) and light (&ldquo, OFF/non-bearing&rdquo, ) yield in pistachio (Pistacia vera L.) has been reported to result from the abscission of inflorescence buds on high yielding trees during the summer, but the regulatory mechanisms involved in this bud abscission remain unclear. The analysis provides insights into the transcript changes between inflorescence buds on bearing and non-bearing shoots, that we indicated as &ldquo, ON&rdquo, and &ldquo, OFF&rdquo, and shed light on the molecular mechanisms causing premature inflorescence bud abscission in the pistachio cultivar &ldquo, Bianca&rdquo, which can be related to the alternate bearing behavior. In this study, a transcriptome analysis was performed in inflorescence buds of &ldquo, shoots. A total of 14,330 differentially expressed genes (DEGs), most of which are involved in sugar metabolism, plant hormone pathways, secondary metabolism and oxidative stress pathway, were identified. Our results shed light on the molecular mechanisms underlying inflorescence bud abscission in pistachio and we proposed a hypothetical model behind the molecular mechanism causing this abscission in &ldquo, shoots. Results highlighted how changes in genes expressed in nutrient pathways (carbohydrates and mineral elements) in pistachio &ldquo, vs. &ldquo, inflorescence buds triggers a cascade of events involving trehalose-6-phosphate and target of rapamycin (TOR) signaling, SnRK1 complex, hormones, polyamines and ROS which end, through programmed cell death and autophagy phenomena, with the abscission of inflorescence buds. This is the first study reporting gene expression profiling of the fate of &ldquo, inflorescence buds associated with the alternate bearing in the pistachio.

In order to gain insight into the complex molecular networks driving legume adaptation caused by climate change, it is necessary to deeply characterize the existing germplasm in response to the environmental constraint predicted to worsen in the near future: drought. In this study, we propose to perform a three-year deep agronomic characterization of local genotypes of selected legumes in abiotic stressing conditions through controlled and field experiments conducted in several countries of the Mediterranean basin (Italy, Spain, Algeria, Tunisia, Turkey, Lebanon, and Croatia). These phenotypic analyses will be integrated with a multi-omic approach aiming at identifying the key players involved in the modulation of the analyzed traits that includes the analysis of the plant methylome, transcriptome, and proteome. Following this approach, we propose to deliver epigenomic markers linked with rapid adaptation mechanisms in response to drought. Besides, new genetic variability by breeding could be created in stressing conditions and produce the basis for the obtainment of more productive cultivars in worsening environments. The epigenetic marks identified in “omic” activities will be validated in molecular marker-assisted selection in F2−F4 populations. Finally, specific rhizobia strains for the best evaluated genotypes will be identified in order to enhance symbiotic nitrogen fixation in drought stress conditions with selected cultivars.

The relationship of two geographically and ecologically separated populations of Turraea socotrana Styles and F. White (Meliaceae), a vulnerable and scattered shrub from the island of Socotra (Yemen), was explored using preliminary molecular data. The nuclear ribosomal ITS region was used to screen the level of genetic divergence of T. socotrana from ecologically distant localities in comparison to a few other species of Turraea and closely related genera. The individuals from the inland (Diksam) differed from the western coastal ones (Ma’alah) by vegetative characters and by the rbcL gene. This may be due to the fact that the population from Ma’alah grows on lithosoil slopes directly exposed to moist winds coming from the sea, whereas the population of Diksam occurs on arid cliffs overlooking the inland of the island. The ITS sequences grouped the studied populations from Socotra together and separated them from other species of Turraea that are morphologically similar andoccurring in East Africa. Considering the differences recorded in the rbcL gene, we suggest that the populations of T. socotrana investigated here on only a few specimens from two different areas on the island, deserve more research. Our preliminary study potentially indicates that there may be independent evolutionary significant units in this species, however, more research including a wider sampling and comparison to other taxa is needed.

An integrated approach to the study of taxa of the genus Hypericum occurring in Sicily is proposed. The results of morphological, biochemical, and molecular analyses are combined to better assess the relationships between the species investigated and test the suitability of DNA barcoding technique in the discrimination of these taxa. For the name Hypericum aegypticum subsp. webbii (Spach) N. Robson a lectotype is designated. For Hypericum triquetrifolium Turra a lectotype and a supporting epitype are designated. The presence of Hypericum perforatum L. subsp. perforatum is excluded from Sicily and the previous reports have to be referred to H. perforatum subsp. veronense (Schrank) Ces. Hypericum perfoliatum L. and H. pubescens Boiss. are close morphologically and chemically, as well as based on the results from rcbL marker, although belonging to different sections. Biochemical analyses confirmed the relevant amounts in bioactive metabolites of the studied taxa. Hypericum perfoliatum L. is proposed as a valid alternative to H. perforatum L. for cultivation with phytotherapic purposes.

Xylella fastidiosa subsp. pauca (Xfp) is a gram-negative pathogenic bacteria responsible for serious diseases (Purcell, 2013) that inflicts considerable economic loss (Li et al., 2007; Luvisi et al., 2017). The pathogen has been linked to olive quick decline syndrome (OQDS). This devastating olive disease was first observed in Salento (Apulia, southeastern Italy) in 2009. Infected trees respond to Xfp infection with scattered desiccation of twigs and small branches in the upper crown, which extend to the rest of the canopy, showing the characteristic blight effect. The disease causes tree death within a few years from the onset of symptoms (Martelli, 2016). The primary agronomic procedure for counteracting the infection is by heavy pruning to stimulate new growth (Martelli et al., 2016).However, this does not prevent the withering and desiccation of upper vegetation in the infected tree. Lignin deposition increases the tolerance of some hosts to Xylella fastidiosa. Elevated concentration of quinic acid, a lignin precursor, less concentration of hydroxytyrosolglucoside and the up-regulation of cinnamoyl-CoA reductase and polyphenol oxidase were observed in the most tolerant olive cultivar, Leccino (Sabella et al., 2018). In this opinion article, we explore the use of a portable instrument to detect OQDS, based on the host responses at the transcript level. This approach was proposed previously to detect Huanglongbing, a severe disease affecting Citrus worldwide (Dandekar et al., 2010;Martinelli et al., 2014b). These innovative mthods of plant disease detection had been reviewed recently (Martinelli et al., 2014a).

Pancratium maritimum L. (Amaryllidaceae) is a geophyte occurring in the Mediterranean region, from the Black Sea to part of the Atlantic coast. This plant is receiving much attention from the international scientific community due to its value as a bioindicator, the potential industrial value of its chemical compounds, and its use as a commercial ornamental plant. Plant morphometry and sequences of three plastid DNA regions (rbcL, matK, trnH-psbA) were used to assess the phenotypic and genetic variability of this taxon and its closest congeneric species (in particular Pancratium linosae, from the volcanic island of Linosa) in the Central Mediterranean (Sicily, Tunisia and surrounding islands). Pancratium maritimum and P. linosae cannot be distinguished based on morphological and genetic data and should belong to the same taxon. Our results also highlight a diversified gene pool in P. maritimum that is worth preserving. The lectotypes of the names Halmira stellaris, Pancratium angustifolium and Pancratium foetidum are here designated.

Dwarf fan palm (Chamaerops humilis L.) is an important Mediterranean species well known for many uses such as gardening, environmental restoration, and technological uses. Dwarf fan palm is usually propagated from seed, which takes up to 100 days to germinate. The germination pattern of dwarf palm seeds was studied during a 100-days length period in relation to different pre-sowing treatments (hot water, sulphuric acid, or mechanical scarification) in comparison to untreated control. A covariance analysis was performed to test the effect of time within seed-treatment treatment. All germination patterns were significantly fitted by a S-shaped (sigmoidal) distribution function with the general equation y=β+α/(1+exp(-(x-μ)/s)). Treatment with sulphuric acid significantly increased the final germination in comparison to untreated control. No differences were observed in % germination among the other seed treatments. Seed treatments increased by three- to seven-fold the maximum germination rate and reduced by 26% the mean germination time in comparison to untreated control. The reduction in mean germination time, and the increase in percentage germination and germination rate may have economical implication in the production of dwarf palm and its involvement in environmental restoration strategies, with no need to use dangerous or expensive acid pre-treatment in order to increase the propagation success.

Pistachio (Pistacia vera L.) production suffers a high level of alternate bearing. The mechanism underlying this negative phenomenon is different from other species, such as apple and olive. Pistachio produces a high number of inflorescence buds every year that in heavy cropping trees (“ON”) mostly fall during the kernel development phase, which occurs in July-August. Primary metabolites (i.e., carbohydrates) play a key role in the signaling related to inflorescence bud abscission. In this work, RNA-Seq was used as a tool to investigate transcriptome of inflorescence buds and fruits, sampled from branches with low (“OFF”) and high (“ON”) crop load. Reference based RNA-Seq analysis using Arabidopsis thaliana genome was performed to discover differentially regulated genes in “ON” vs. “OFF” branches. In fruits developed on “ON” branches, photosynthesis, terpenoid and alpha-amylase-related genes were induced while tetrapyrrole was repressed; in inflorescence buds, photosynthesis was repressed while two genes involved in terpenoids pathways were still induced in comparison to the buds bore on “OFF” branches. A comparison with citrus transcriptomic data was performed. The data collected in the present study will be further utilized by the completion of pistachio genome and transcriptome de novo assembly.

Red Palm Weevil (RPW, Rhynchophorus ferrugineus Olivier) threatens most palm species worldwide. Until now, no studies have analyzed the gene regulatory networks of Phoenix canariensis (Chabaud) in response to RPW attacks. The aim of this study was to fill this knowledge gap. Providing this basic knowledge is very important to improve its management.Results: A deep transcriptome analysis was performed on fully expanded leaves of healthy non-infested trees and attacked trees at two symptom stages (middle and late infestation). A total of 54 genes were significantly regulated during middle stage. Pathway enrichment analysis showed that phenylpropanoid-related pathways were induced at this stage. More than 3300 genes were affected during late stage of attacks. Higher transcript abundances were observed for lipid fatty acid metabolism (fatty acid and glycerolipids), tryptophan metabolism, phenylpropanoid metabolism. Key RPW-modulated genes involved in innate response mediated by hormone crosstalk were observed belonging to auxin, jasmonate and salicylic acid (SA) pathways. Among transcription factors, some WRKYs were clearly induced. qRT-PCR validation confirmed the upregulation of key genes chosen as validation of transcriptomic analysis.Conclusion: A subset of these genes may be further analyzed in future studies to confirm their specificity to be induced by RPW infestations., The present research work was financially supported by Propalma project funded by the “Ministero delle Politiche Agricole, Alimentari e Forestali.”

The systematic relationships between the five different subspecies actually recognized within Dianthus rupicola (subsp. aeolicus , subsp. bocchorianus , subsp. hermaensis, subsp. lopadusanus and subsp. rupicola ), were assessed by means of morphometric and molecular analysis. Our results highlighted the molecular differences between the five subspecies of D. rupicola and a morphological differentiation of four groups being D. rupicola subsp. aeolicus and D. rupicola subsp. rupicola partly overlapping. At the present state of knowledge, a subspecific status seems the most appropriate for all the recognized subspecies of D. rupicola . The names D. aeolicus , D. bisignanii var. virescens , D. hermaeensis , D. rupicola are here lectotypified respectively on specimens preserved at PAL, NAP, P, and BOLO, while D. bisignanii s.str. is lectotypified on a Tenore’s image and a epitype (at K) is designated. Concerning the name D. rupicola subsp. bocchorianus the holotype is traced.

Dwarf fan palm (Chamaerops humilis) plays an important ecological role in the thermo Mediterranean vegetation stage, both in woodlands, xerophitic shrub communities and degraded ecosystems. Dwarf fan palm is typically propagated from seeds. Whereas other palm species show reduced germination after few months of seed storage, no information is available on the effects of storage time on seed germinability . We examined the germination pattern of dwarf palm seeds aged after a storage of four, six or eight months in comparison to fresh seed (control). A covariance analysis was performed to test the effect of time within seed-storage treatment. The germination patterns were significantly fitted by a S-shaped (sigmoidal) distribution function with the general equation y=β+α/(1+exp(-(x-μ)/s)). Short-time storage significantly increased both final seed germination and maximum germination rate, and reduced mean germination time in comparison to unstored control. If considering that we did not make any seed treatment before sowing, these results may be due to an increased oxygen diffusion and water permeability through the seed hard coat during time.