Comparative studies on the structure and adhesion of setae in G. gecko and G. swinhonis

Scanning electron microscopy (SEM) and histological techniques were used to observe and study the setae structures of two gecko species (G. gecko and G. swinhonis) and the relationships between these structures and the adhesive forces. The SEM results showed that the setae of these two species were densely distributed in an orderly fashion, and branched with curved tips. The setae of G. gecko had cluster structures, each cluster containing 4-6 setae whose terminal branches curved towards the center of the toes at ~ 10o, the tips of the branches like spatulae and densely arrayed at an interval of less than 0.2―0.3 μm. On the contrary, the branch tips in the setae of G. swinhonis were curled, and the terminal parts of setae curved towards the center of the toes at various angles. Usually the setae of these gecko species branch twice at the top at intervals greater than that of G. gecko. The histological observation found that inside the setae of these two species there were plenty of unevenly distributed contents, such as epithelia, fat cells, pigmental cells and muscle tissue, but no gland cells existed. The results of functional experiments suggested that modifying the structure of gecko's setae could reduce its adhesive ability dramatically, demonstrating the positive correlation between the structure of the gecko's setae and its adhesive ability. The above results provide important information in designing bio-mimic setae and bio-gecko robots.     

A new species of <Emphasis Type="Italic">Elaphoglossum</Emphasis> sect. <Emphasis Type="Italic">Lepidoglossa</Emphasis> subsect. <Emphasis Type="Italic">Muscosa</Emphasis> (Dryopteridacae) with cristate spores

A new species from the Bolivian highlands is described as Elaphoglossum cristatum. It is very similar to E. engelii but is characterized by a (for subsect. Muscosa unique) cristate perispore structure with irregular deposits (versus papillate spores), more densely ciliate petiole scales (50–80 versus 10–30 cilia per scale), somewhat thicker blade texture, denser scale cover, and paler, more reddish rhizome scales.     

Fecundity and feeding of <Emphasis Type="Italic">Galerucella calmariensis</Emphasis> and <Emphasis Type="Italic">G. pusilla</Emphasis> on <Emphasis Type="Italic">Lythrum salicaria</Emphasis>

Fecundity and feeding of two introduced sibling biological control species, Galerucella calmariensis and G. pusilla (Coleoptera: Chrysomelidae) on purple loosestrife, Lythrum salicaria L. (Lythraceae) were compared at constant temperatures of 12.5, 15, 20, 25, and 27.5 °C. Larval feeding was also carried out at 30 °C, but at this temperature, larvae developed only to the L2 stage and none pupated. Thus, data for this temperature were not used in the analysis. There were significant species × temperature interactions in fecundity. Of the two species, Galerucella pusilla laid more eggs. Although egg production of both species was lowest at 12.5 °C and increased to 20 °C, at higher temperatures, the two species reacted differently. From 25 to 27.5 °C, egg production decreased for G. pusilla, but G. calmariensis fecundity peaked at 27.5 °C. Significant temperature × species × life-stage interactions were also observed in feeding. For each species, the amount of feeding varied with temperature and stage of development. Galerucella pusilla adults consumed more foliage at 15, 20, and 27.5 °C. However, at 12.5 °C G. calmariensis adults fed more than G. pusilla. G. pusilla larvae consumed an average of 25% less foliage than G. calmariensis. The lower larval consumption of G. pusilla suggests that when food is limited, G. pusilla larvae may have a higher survival rate because of its ability to complete larval development with less food and produce more progeny due to its greater fecundity. When food is not limited neither species would have a competitive advantage and both species could coexist temporally and spatially. However, since G. calmariensis larvae consumed more leaf material, the larval stage of this species would have a greater impact on purple loosestrife than G. pusilla.     

Polymorphism of canonical and noncanonical <Emphasis Type="Italic">gypsy</Emphasis> sequences in different species of <Emphasis Type="Italic">Drosophila </Emphasis><Emphasis Type="Italic">melanogaster</Emphasis> subgroup: possible evolutionary relations

Mobile genetic elements constitute a substantial part of eukaryotic genome and play an important role in its organization and functioning. Co-evolution of retrotransposons and their hosts resulted in the establishment of control systems employing mechanisms of RNA interference that seem to be impossible to evade. However, “active” copies of endogenous retrovirus gypsy escape cellular control in some cases, while its evolutionary elder “inactive” variants do not. To clarify the evolutionary relationship between “active” and “inactive” gypsy we combined two approaches: the analysis of gypsy sequences, isolated from G32 Drosophila melanogaster strain and from different Drosophila species of the melanogaster subgroup, as well as the study of databases, available on the Internet. No signs of “intermediate” (between “active” and “inactive”) gypsy form were found in GenBank, and four full-size G32 gypsy copies demonstrated a convergence that presumably involves gene conversion. No “active” gypsy were revealed among PCR generated gypsy ORF3 sequences from the various Drosophila species indicating that “active” gypsy appeared in some population of D. melanogaster and then started to spread out. Analysis of sequences flanking gypsy variants in G32 revealed their predominantly heterochromatic location. Discrepancy between the structure of actual gypsy sites in G32 and corresponding sequences in database might indicate significant inter-strain heterochromatin diversity. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of <Emphasis Type="Italic">Gentiana dinarica</Emphasis> Beck.

Gentiana dinarica Beck, rare and endangered species of Balkan Dinaric alps, was in vitro propagated (micropropagated) from axillary buds of plants collected at Mt. Tara, Serbia. G. dinarica preferred MS to WPM medium, with optimal shoot multiplication on MS medium with 3% sucrose, 1.0 mg l⁻¹ BA and 0.1 mg l⁻¹ NAA. Rooting was not clearly separated from shoot multiplication since BA did not completely inhibit root initiation. Spontaneous rooting on plant growth regulator-free medium occurred in some 30% of shoot explants. Rooting was stimulated mostly by decreased mineral salt nutrition and a medium with 0.5 MS salts, 2% sucrose and 0.5–1.0 mg l⁻¹ IBA was considered to be optimal for rooting. Rooted plantlets were successfully acclimated and further cultured in peat-based substrate.     

Phylogenetic,Inter, and Intraspecific Sequence Analysis of <Emphasis Type="Italic">spo0A</Emphasis> Gene of the Genus <Emphasis Type="Italic">Geobacillus</Emphasis>

In this work, the variability of spo0A gene in the genus Geobacillus and applicability of this gene for the taxonomy within this genus were evaluated. The protein Spo0A is the master regulator of the endospore-forming process in the all endospore-forming bacteria. Geobacillus genus-specific primers GEOSPO were designed based on the sequences of Geobacillus spo0A gene available through the public databases. Inter and intraspecific variability of Geobacillus spo0A gene was determined after sequencing of the GEOSPO-PCR products. Geobacillus spo0A sequence analysis showed that three species—Geobacillus thermodenitrificans, G. stearothermophilus, and G. jurassicus—could be easily identified. Similarity between the sequences of these species and the other species were in the range of 83.3%–92.0%. In contrast, intraspecific similarity of G. thermodenitrificans and G. stearothermophilus was high—above 99.0%. Similarity of spo0A sequences of G. subterraneus–G. uzenensis species cluster also matched this interval. Intercluster similarity between G. lituanicus–G. thermoleovorans–G. kaustophilus–G. vulcani and G. thermocatenulatus–G. gargensis–G. caldoxylosilyticus–G. toebii–G. thermoglucosidasius species clusters, as well as interspecific similarity within these two clusters was in the range of the intraspecific similarity determined for G. thermodenitrificans and G. stearothermophilus. It was also determined that spo0A cannot be used as the phylogenetic marker for the genus Geobacillus.     

<Emphasis Type="Italic">Hirsutella proturicola</Emphasis> sp. nov. isolated from a proturan, <Emphasis Type="Italic">Baculentulus</Emphasis> densus (Protura,Hexapoda)

A new species of Hirsutella, H. proturicola, isolated from a subterranean proturan (Baculentulus densus; Protura, Hexapoda), is described and illustrated. Hirsutella proturicola is characterized by producing monoblastic phialides of 24–51.5 × 2.5–5 μm with a slightly roughened neck, fusiform and curved conidia of 9–18 × 2.5–4 μm that have a truncate base and a papillate projection often capped with sheath-like mucilage, and pluricellular, globose to subglobose chlamydospores of 21–48 × 21–41.5 μm. This species is morphologically and phylogenetically close to H. rostrata, an acaropathogenic species, but can be distinguished from the size of the phialides and the size and shape of the conidia.     

<Emphasis Type="Italic">In vitro</Emphasis> regeneration of <Emphasis Type="Italic">Salvia nemorosa</Emphasis> L. from shoot tips and leaf explants

Summary Shoot tips and leaves excised from in vitro shoot cultures of Salvia nemorosa were evaluated for their organogenic capacity under in vitro conditions. The best shoot proliferation from shoot tips was obtained on Murashige and Skoog (MS) medium supplemented with 8.9 μM 6-benzylaminopurine (BA) and 2.9 μM indole-3-acetic acid (IAA). Leaf lamina and petiole explants formed shoots through organogenesis via callus stage and/or directly from explant tissue. The highest values for shoot regeneration were obtained with 0.9 μM BA and 2.9 μM IAA for lamina explants. No shoot organogenesis was obtained on leaf explants cultured on MS medium supplemented with α-naphthaleneacetic acid (NAA). The regenerated shoots rooted the best on MS medium containing 0.6 μM IAA or 0.5 μM NAA. In vitro-propagated plants were transferred to soil with a survival rate of 85% after 3 mo.     

Setal variability of <Emphasis Type="Italic">Hydrozetes lemnae</Emphasis> and <Emphasis Type="Italic">H. thienemanni</Emphasis> (Acari: Oribatida: Hydrozetidae)

Setal variability and the other morphological characters of juvenile stages and adult of Hydrozetes lemnae (Coggi, 1897) and H. thienemanni Strenzke, 1943 were investigated. In the juveniles of both species the length and shape of some setae vary, especially in the gastronotic region, more so in H. lemnae, which is parthenogenetic and reproduces by thelytoky, than in H. thienemanni, which is dioecious. The former species usually has more thick setae in the anterior and medial regions of the gastronotum, especially in the larva, compared to the latter. In the juveniles of H. lemnae the prodorsal setae le and in are longer, and in the nymphs the gastronotal setae of the l-series are usually longer than in H. thienemanni. These species differ distinctly by the number of long setae in the posterior part of the nymphs; in H. lemnae three pairs of long setae occur, while in H. thienemanni only two pairs; the respective juvenile stages of H. lemnae are also smaller than those of H. thienemanni. In the adults the number of c-series setae varies, as seta c ₁ is lost, and in some individuals also seta c ₃, and only seta c ₂ remains.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation from young and mature explants of thyme (<Emphasis Type="Italic">Thymus vulgaris</Emphasis> and <Emphasis Type="Italic">T. longicaulis</Emphasis>) resulting in genetically stable shoots

An efficient in vitro propagation protocol, applicable both to young and mature explants of two Thymus spp., results in genetically stable plantlets. In vitro-grown shoot tips of Thymus vulgaris L. were exposed to cytokinins (6-benzyladenine, kinetin, and thidiazuron) alone or in combination with auxins, gibberellic acid (GA₃) and/or silver nitrate in order to optimize in vitro shoot proliferation. Optimum shoot proliferation (97% regeneration rate, with 8.6 shoots produced per explant) was obtained when semi-solid Murashige and Skoog (MS) medium was supplemented with 1 mg L⁻¹ kinetin and 0.3 mg L⁻¹ GA₃. Rooting of the shoots was easily obtained on semi-solid MS medium that was either hormone-free or supplemented with auxins. However, the best root apparatus (92.5% rooting rate, with 19 adventitious roots per shoot) developed on MS medium supplemented with 0.05 mg L⁻¹ 2,4-dichlorophenoxyacetic acid. Genetic stability was confirmed in the in vitro-germinated mother plant as well as the shoots that underwent two, four, six, eight, or ten cycles of in vitro subculturing by random amplified polymorphic DNA (RAPD) analysis. When applied to the micropropagation of mature shoot tips of T. longicaulis C. Presl subsp. longicaulis var. subisophyllus (Borbás) Jalas, the optimized in vitro propagation protocol resulted in a 97.5% shoot regeneration rate, with five shoots formed per explant, and 100% rooting. Rooted plantlets of both species were transferred to 250-mL plastic pots and successfully acclimatized by gradually reducing the relative humidity.     

Molecular analysis of the genus <Emphasis Type="Italic">Anoxybacillus</Emphasis> based on sequence similarity of the genes <Emphasis Type="Italic">recN</Emphasis>, <Emphasis Type="Italic">flaA</Emphasis>, and <Emphasis Type="Italic">ftsY</Emphasis>

Genome predictions based on selected genes would be a very welcome approach for taxonomic studies. We analyzed three genes, recN, flaA, and ftsY, for determining if these genes are useful tools for systematic analyses in the genus Anoxybacillus. The genes encoding a DNA repair and genetic recombination protein (recN), the flagellin protein (flaA), and GTPase signal docking protein (ftsY) were sequenced for ten Anoxybacillus species. The sequence comparisons revealed that recN sequence similarities range between 61% and 99% in the genus Anoxybacillus. Comparisons to other bacterial recN genes indicated that levels of similarity did not differ from the levels within genus Anoxybacillus. These data showed that recN is not a useful marker for the genus Anoxybacillus. A 550–600-bp region of the flagellin gene was amplified for all Anoxybacillus strains except for Anoxybacillus contaminans. The sequence similarity of flaA gene varies between 61% and 76%. Comparisons to other bacterial flagellin genes obtained from GenBank (Bacillus, Pectinatus, Proteus, and Vibrio) indicated that the levels of similarity were lower (3–42%). Based on these data, we concluded that the variability in this single gene makes it a particularly useful marker. Another housekeeping gene ftsY suggested to reflect the G+C (mol/mol) content of whole genome was analyzed for Anoxybacillus strains. A mean difference of 1.4% was observed between the G+C content of the gene ftsY and the G+C content of the whole genome. These results showed that the gene ftsY can be used to represent whole G+C content of the Anoxybacillus species.     

Revised treatment of <Emphasis Type="Italic">Memecylon</Emphasis> sect. <Emphasis Type="Italic">Afzeliana</Emphasis> (<Emphasis Type="Italic">Melastomataceae: Olisbeoideae</Emphasis>), including three new species from Cameroon

Summary  Seven new names at species rank are proposed in Memecylon sect. Afzeliana Jacq.-Fél., a group of forest shrubs and small trees confined to Guineo-Congolian Africa. The group is centred in Cameroon, where 17 of the 20 species occur. A new flower type, the “star-flower” in Memecylon is revealed, and its taxonomic and ecological importance discussed. Three new, locally endemic species from the South West Province of Cameroon are described, mapped and illustrated: M. kupeanum R. D. Stone, Ghogue & Cheek, M. bakossiense R. D. Stone, Ghogue & Cheek, and M. rheophyticum R. D. Stone, Ghogue & Cheek. Two new names, M. accedens R. D. Stone, Ghogue & Cheek and M. hyleastrum R. D. Stone & Ghogue and one new combination, M. mamfeanum (Jacq.-Fél.) R. D. Stone, Ghogue & Cheek are provided at species level for three taxa originally proposed as varieties of M. afzelii G. Don. The taxon M. arcuatomarginatum var. simulans Jacq.-Fél. is also elevated to species status, as M. simulans (Jacq.-Fél.) R. D. Stone & Ghogue. Conservation assessments are provided for all the newly named taxa. A key is provided to the species of Memecylon sect. Afzeliana.     

Strong Expression and Conserved Regulation of <Emphasis Type="Italic">ACT2</Emphasis> in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> and <Emphasis Type="Italic">Physcomitrella patens</Emphasis>

Arabidopsis ACT2 represents an ancient class of vegetative plant actins and is strongly and constitutively expressed in almost all Arabidopsis sporophyte vegetative tissues. Using the beta glucuronidase report system, the studies showed that ACT2 5′ regulatory region was significantly more active than CaMV 35S promoter in Arabidopsis seedlings and gametophyte vegetative tissues of Physcomitrella patens. Its activity was also observed in rice and maize seedlings. Thus, the ACT2 5′ regulatory region could potentially serve as a strong regulator to express a transgene in divergent plant species. ACT2 5′ regulatory region contained 15 conserved sequence elements, an ancient intron in its 5′ un-translated region (5′ UTR), and a purine-rich stretch followed by a pyrimidine-rich stretch (PuPy). Mutagenesis and deletion analysis illustrated that some of the conserved sequence elements and the region containing PuPy sequences played regulatory roles in Arabidopsis. Interestingly, mutation of the conserved elements did not lead a dramatic change in the activity of ACT2 5′ regulatory region. The ancient intron in ACT2 5′ UTR was required for its strong expression in both Arabidopsis and P. patens, but did not fully function as a canonical intron. Thus, it was likely that some of the conserved sequence elements and gene structures had been preserved in ACT2 5′ regulatory region over the course of land plant evolution partly due to their functional importance. The studies provided additional evidences that identification of evolutionarily conserved features in non-coding region might be used as an efficient strategy to predict gene regulatory elements.     

Review of naupliar development among Miraciidae (Copepoda,Harpacticoida) with a naupliar description of <Emphasis Type="Italic">Paramphiascella</Emphasis><Emphasis Type="Italic">choi</Emphasis> sp. nov. from Thailand

Both genders of Paramphiascella choi sp. nov. were collected from the green alga Enteromorpha clathrata in Rayong province, Thailand. P. choi shares with other species of the genus: cylindrical body shape, rostrum not bifid, eight-segmented antennules, three-segmented exopodal antenna, and female P5 exopod with five setae. The new species distinguished from other conspecific species by: three-segmented exopodal antenna, inner edge of basis of male P1 and P2 bear a bare ovate-knob each. Enp-1 very elongate, Enp-2 of male P2 transformed into a large, strong, slightly curved and tapering attenuation with two central chitinous ridges, and bearing one medially directed knob close to enp-1. At the base of this knob arise three plumose setae of unequal length. These characters are suggested to be autapomorphies of the new species. Six naupliar stages are obtained and described a key for the identification of stages is provided. Nauplius I has one pair of caudal setae; three-segmented antennules; antenna consists of a coxa, basis, endopod and exopod; mandible has a coxa, basis, endopod and exopod; hindbody bears two caudal setae. Nauplius II develops one aesthetasc on the antennule; antenna has added an arthrite arising from the coxa; mandible has a row of tiny spinulose setae. Nauplius III has added two pairs of caudal setae. Nauplius IV bears bilobed bud of the maxillule armed with two setae and four pairs of caudal setae. Nauplius V bears a multilobed bud of the maxillule with three setae and five pairs of caudal setae. At Nauplius VI, the buds of swimming legs 1 and 2 are added.     

Application of <Emphasis Type="Italic">gyrB</Emphasis> and <Emphasis Type="Italic">parE</Emphasis> sequence similarity analyses for differentiation of species within the genus <Emphasis Type="Italic">Geobacillus</Emphasis>

The primary structures of the genes encoding the β-subunits of a type II topoisomerase (gyrase, gyrB) and a type IV topoisomerase (parE) were determined for 15 strains of thermophilic bacteria of the genus Geobacillus. The obtained sequences were used for analysis of the phylogenetic similarity between members of this genus. Comparison of the phylogenetic trees of geobacilli constructed on the basis of the 16S rRNA, gyrB, and parE gene sequences demonstrated that the level of genetic distance between the sequences of the genes encoding the β-subunits of type II topoisomerases significantly exceeded the values obtained by comparative analysis of the 16S rRNA gene sequences of Geobacillus strains. It was shown that, unlike the 16S rRNA gene analysis, comparative analysis of the gyrB and parE gene sequences provided a more precise determination of the phylogenetic position of bacteria at the species level. The data obtained suggest the possibility of using the genes encoding the β-subunits of type II topoisomerases as phylogenetic markers for determination of the species structure of geobacilli.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation and cryostorage of <Emphasis Type="Italic">Syzygium francissi (Myrtaceae)</Emphasis> by the encapsulation-dehydration method

Summary An efficient procedure for the in vitro propagation and cryogenic conservation of Syzygium francissi was developed. The maximum number of shoots per explant was obtained on a Murashige and Skoog (MS) medium supplemented with 4.5 μM benzyladenine and 0.5 μM indole-3-butyric acid (IBA). The in vitro-propagated shoots produced roots when transferred to MS medium containing IBA, indold-3-acetic acid, or naphthaleneacetic acid at various concentrations. Rooted microshoots were transferred to a coco-peat, perlite, and vermiculite (1∶1∶1) mixture, and hardened off under greenhouse conditions. Ninety-five percent of rooted shoots successfully acclimatized in the greenhouse. Shoot tips excised from in vitro-grown plants were successfully cryostoraged at −196°C by the encapsulation-dehydration method. A preculture of formed beads on MS medium containing 0.75 M sucrose for 1 d, followed by 6 h dehydration (20% moisture content) led to the highest survival rate after cryostorage for 1h. This method is a promising technique for in vitro propagation and cryopreservation of shoot tips from in vitro-grown plantlets of S. francissi germplasm.     

Pollination biology of <Emphasis Type="Italic">Disanthus cercidifolius</Emphasis> var. <Emphasis Type="Italic">longipes</Emphasis>, an endemic and endangered plant in China

Disanthus cercidifolius Maxim. var. longipes H.T. Chang usually has two inflorescences growing in opposite directions in the axillae, but occasionally three inflorescences grow paratactically. The typical flowering process could be divided into 4 periods: “Pre-dehiscence”, “Initial dehiscence”, “Full dehiscence” and “Withering”. Both the natural population and the planted population had a flowering peak of 15–35 days after the first flower bloomed. There were significant differences between the time courses of flowering of the two populations. Out-crossing is the main breeding system in this species. And autogamy decreases the risk of reproductive failure of this species. The main insect pollinators of D. cercidifolius var. longipes are Episyrphus balteatus de Geer, Scaptodrosophila coracina Kikkawa and Peng, Polistes olivaceus de Geer, Apis cerana Fabricius, Nezara viridula L. and Coccinella septempunctata L., and so on. Among the insects, S. coracina and E. balteatus are the most important and efficient pollinators, but others are inefficient pollinators. Though wind pollination is not efficient, it guarantees reproduction when insect pollinators are not available. “Mass flowering” is an adaptive behavior and reproductive strategy of this species, and “few fruiting” could be caused by the lack of pollinators.     

Viscoelastic features of adhesive setae of the tokay gecko (<Emphasis Type="Italic">Gekko gecko</Emphasis> L.)

Deformations of particular setae of adhesive toe pad of the tokay gecko were investigated by atomic-force microscopy. The effective elastic modulus of the investigated setae varying within 0.34–19 GPa, a pronounced hysteresis was observed during reversible bending of setae. The hysteresis-related energy losses may be as high as 98% of the total bending work. The pronounced viscous features of the setae contradict the hypothesis of dynamic self-cleaning of the gecko adhesive cover, according to which the setae are considered as absolutely elastic cantilever beams.     

Mesenterial filaments of the black coral <Emphasis Type="Italic">Cirrhipathes</Emphasis> cfr. <Emphasis Type="Italic">anguina</Emphasis> provide a home to developing nauplii

Inspection of two female colonies of the monopodial black coral Cirrhipathes cfr. anguina from the coral reef of the Marine Park of Bunaken (Indonesia) revealed the occurrence of crustacean developing eggs within the mesenterial filaments of the polyps. Egg diameter, which in the smallest gametes was about 50–60 μm, increased in tandem with embryo development, reaching the value of 170 μm, at the nauplius stage. The attribution to the crustacean taxon was derived from morphological investigations carried out in light and electron microscopy (TEM, SEM) on the eggs and on the embryos removed from them. The final stage of nauplius was characterised by three pairs of appendages: uniramouse antennulae, biramouse antennae and manidibulae. In addition, naupliar eye and caudal setae were also evident. These nauplii were ascribed to the larval stage of an unidentified species. Coral/copepod association could represent a reproductive strategy, put into action by some marine copepods. Incubation within an appropriate host prevents predation by planktotrophic organisms, thus reducing population depletion.     

Anatomical changes induced by increasing NaCl salinity in three fodder shrubs, <Emphasis Type="Italic">Nitraria retusa</Emphasis>, <Emphasis Type="Italic">Atriplex halimus</Emphasis> and <Emphasis Type="Italic">Medicago arborea</Emphasis>

Nitraria retusa and Atriplex halimus (xero-halophytes) plants were grown in the range 0–800 mM NaCl while Medicago arborea (glycophyte) in 0–300 mM NaCl. Plants were harvested after 120 days of salt-treatment. The present study was designed to study the effect of salinity on root, stem and leaf anatomy, water relationship, and plant growth in greenhouse conditions. Salinity induced anatomical changes in the roots, stems and leaves. The cuticle and epidermis of N. retusa and A. halimus stems were unaffected by salinity. However, root anatomical parameters (root cross section area, cortex thickness and stele to root area ratio), and stem anatomical parameters (stem cross section area and cortex area) were promoted at 100–200 mM NaCl. Indicating that low to moderate salinity had a stimulating effect on root and stem growth of these xero-halophytic species. At higher salinities, root and stem structures were altered significantly, and their percentages of reduction were higher in A. halimus than in N. retusa whereas, in M. arborea, they were strongly altered as salinity rose. NaCl (100–300 mM) reduced leaf water content by 21.2–56.2% and specific leaf area by 51–88.1%, while increased leaf anatomical parameters in M. arborea (e.g. increased thickness of upper and lower epidermis, palisade and spongy mesophyll, entire lamina, and increased palisade to spongy mesophyll ratio). Similar results were evidenced in A. halimus leaves with salinity exceeding 100 mM NaCl. Leaves of N. retusa were thinner in salt-stressed plants while epidermis thickness and water content was unaffected by salinity. The size of xylem vessel was unchanged under salinity in the leaf’s main vein of the three species while we have increased number in M. arborea leaf main vein in the range of 200–300 mM NaCl. A longer distance between leaf vascular bundle, a reduced size and increased number of xylem vessel especially in stem than in root vascular system was evidenced in M. arborea treated plants and only at (400–800 mM) in the xero-halophytic species. The effects of NaCl toxicity on leaf, stem and root ultrastructure are discussed in relation to the degree of salt resistance of these three species. Our results suggest that both N. retusa and A. halimus show high tolerance to salinity while M. arborea was considered as a salt tolerant species.