A taxonomic backbone for the Plumbaginaceae (Caryophyllales).

A taxonomic backbone of the Plumbaginaceae is presented and the current state of knowledge on phylogenetic relationships and taxon limits is reviewed as a basis for the accepted taxon concepts. In total, 4,476 scientific names and designations are treated of which 30 are not in the family Plumbaginaceae. The Plumbaginaceae are subdivided in three tribes with 26 genera and 1,179 accepted species. Two subgenera, 17 sections, two subsections and 187 infraspecific taxa are accepted. At the species and infraspecific level 2,782 synonyms were assigned to accepted taxa, whereas 194 names were excluded from the core checklist (i.e., unplaced taxa, infrageneric subdivisions with still uncertain application, names of verified uncertain application, invalid horticultural names, excluded names from other families, other excluded designations, and unresolved names). The EDIT Platform for Cybertaxonomy was utilized as the tool to compile and manage the names and further taxonomic data under explicit taxon concepts. Secundum references are given in case taxon concepts were taken from the literature, whereas this study serves as reference for newly circumscribed taxa. The family's division into the tribes Aegialitideae, Limonieae, and Plumbagineae departs from earlier two-subfamily classifications, prompted by recent phylogenetic findings that challenge the subfamilial affinity of Aegialitis. The genus Acantholimon was extended to include Gladiolimon, as currently available phylogenetic and morphological data support this merger. In Limonium, all accepted species could be assigned to sections and subsections or the "Mediterranean lineage", respectively, making use of the phylogenetic distribution of their morphological characters and states. A new combination and/or status is proposed for Dyerophytumsocotranum, Limoniumthymoides, Limonium×fraternum, Limonium×rossmaessleri, and Limoniumsect.Jovibarba. Special attention is given to nomenclatural issues, particularly for Staticenomenambiguum to resolve the names under accepted names. The use of artificial groupings like "aggregates", "complexes" and "species groups" in alpha-taxonomic treatments is discussed. The taxonomic backbone will receive continued updates and through the Caryophyllales Taxonomic Expert Network, it contributes the treatment of the Plumbaginaceae for the World Flora Online.

Plant diversity of Hyrcanian relict forests: An annotated checklist, chorology and threat categories of endemic and near endemic vascular plant species.

In this paper a critical annotated checklist of 256 endemic and near endemic species belonging to 152 genera and 50 families of flowering plants known from Hyrcanian relict forests is presented. Distribution maps of taxa, elevational range, number of known records, chorotypes, life forms, IUCN threat categories and habitat types are also provided. The chorotypes are categorized into eight main patterns: 1) the Omni-Hyrcanian pattern (OH), 2) West Hyrcanian pattern (WH), 3) Manjil-Rudbar pattern (MR), 4) Central Hyrcanian pattern (CH), 5) Central and East Hyrcanian pattern (CEH), 6) East Hyrcanian pattern (EH), 7) Alborz-Hyrcanian pattern (AH), and 8) Euxino-Hyrcanian pattern (XH). The richness and distribution maps were generated based on 5408 records gained from herbarium specimens and literature records. The life form spectra show that the majority of taxa (54.7%) belong to hemicryptophytes, followed by the tuberous, bulbous and parasitic geophytes with 45 species (17.6%) and phanerophytes with 28 taxa (10.9%). The conservation status of species according to IUCN criteria indicates that 30 taxa are Critically Endangered, 52 taxa Endangered, 30 taxa Vulnerable, 25 taxa Near Threatened and 81 taxa are of Least Concern. Our present data were not sufficient to evaluate 38 taxa that are categorized here as Data Deficient. The new combination of Leutea translucens (=Peucedanum translucens) is validated with inclusion of Peucedanum hyrcanicum as its synonym. The disjunct occurrence of the Caucasian species Gentiana grossheimii is reported from the eastern parts of the Hyrcanian forests in Iran for the first time. We conclude that (i) the Hyrcanian forests and associated habitats in the northern slopes of the Alborz Mountains harbour tremendous floristic diversity of high conservation priority, and (ii) the Hyrcanian forest zone is an important and unique center of endemism within the Euro-Siberian region that should be considered a floristic province with a large number of relict species.

Functional structure of plant communities along salinity gradients in Iranian salt marshes.

Salt marshes are unique habitats between sea or saline lakes and land that need to be conserved from the effects of global change. Understanding the variation in functional structure of plant community along environmental gradients is critical to predict the response of plant communities to ongoing environmental changes. We evaluated the changes in the functional structure of halophytic communities along soil gradients including salinity, in Iranian salt marshes; Lake Urmia, Lake Meyghan, Musa estuary, and Nayband Bay (Iran). We established 48 plots from 16 sites in four salt marshes and sampled 10 leaves per species to measure leaf functional traits. Five soil samples were sampled from each plot and 30 variables were analyzed. We examined the changes in the functional structure of plant communities (i.e., functional diversity [FD] and community weighted mean [CWM]) along local soil gradients using linear mixed effect models. Our results showed that FD and CWM of leaf thickness tended to increase with salinity, while those indices related to leaf shape decreased following soil potassium content. Our results suggest that the variations in functional structure of plant communities along local soil gradients reveal the effect of different ecological processes (e.g., niche differentiation related to the habitat heterogeneity) that drive the assembly of halophytic plant communities in SW Asian salt marshes.

A Review of C4 Plants in Southwest Asia: An Ecological, Geographical and Taxonomical Analysis of a Region With High Diversity of C4 Eudicots.

Southwest Asia is climatically and topographically a highly diverse region in the xeric belt of the Old World. Its diversity of arid habitats and climatic conditions acted as an important area for the evolution and diversification of up to 20 (of 38 known) independent Eudicot C4 origins. Some of these lineages present unique evolutionary strategies like single-cell functioning C4 and C3-C4 switching mechanisms. The high diversity of C4 taxa in Southwest (SW) Asia is also related to the presence of seven phytogeographic zones including the Irano-Turanian region as a center of diversification of many Caryophyllales lineages and the Somali-Masai region (Southern Oman and Yemen) as a center of diversification for C4 Monocots. Nevertheless, the C4 flora of SW Asia has not received detailed attention. This paper presents a comprehensive review of all known C4 species in the area based on a literature survey, own floristic observations, as well as taxonomic, phylogenetic and herbarium data, and δ13C-isotope ratio analysis. The resulting checklist includes a total number of 923 (861 native, of which 141 endemic, and 62 introduced) C4 species, composed of 350 Eudicots and 509 Monocots, most of which are therophytic and hemicryptophytic xerophytes with pluriregional and Irano-Turanian distribution. Two hundred thirty-nine new δ13C-isotope ratios of C4 and C3 plants, as well as some taxonomic changes are presented. An analysis of the distribution of the three main C4 plant families (Chenopodiaceae, Poaceae, and Cyperaceae) in the region in relation to climatic variables indicates that the increase of C4 species follows more or less a latitudinal gradient similar to global patterns, while separate taxonomic groups seem to depend on specific factors as continentality (Chenopodiaceae), average annual temperature (Cyperaceae), and the presence of summer precipitation (Poaceae). An increase of C4 Eudicots in W-E direction even in similar longitudinal belts is explained by a combination of edaphic and climatic conditions. The provided data should encourage a deeper interest in the evolution of C4 lineages in SW Asia and their adaptation to ecological and climatical conditions and awaken interest in the importance of local C4 crops, the conservation of threatened C4 taxa, and awareness of human impacts on the rapid environmental changes in the region.

The elemental composition of halophytes correlates with key morphological adaptations and taxonomic groups.

Halophytes are crucial in the light of increasing soil salinization, yet our understanding of their chemical composition and its relationship to key morphological traits such as succulence or salt excretion is limited. This study targets this issue by exploring the relationship between the elemental composition of 108 plant species from saline environments in Iran and their eco-morphological traits and taxonomy. Leaves and/or photosynthetic shoots of individual species and soils were sampled and analyzed for 20 elements in plant samples and 5 major elements plus % gypsum content, pH, and EC in soil samples. Eu-halophytes and leaf- and stem-succulent and salt-recreting plants showed high concentrations of Na, S, and Mg and low concentrations of Ca and K. In contrast, pseudo-halophytes, facultative-halophytes and eury-hygro-halophytes, which often lack succulent shoots, showed low Na, S, and Mg and high Ca and K concentrations in their leaves. Clear patterns were identified among taxonomic families, with Chenopodiaceae and Plumbaginaceae having high Na and Mg and low Ca and K concentrations, Caryophyllaceae having high K, Poaceae having low Na, and Asteraceae, Boraginaceae, and Brassicaceae showing high foliar Ca concentrations. We conclude that the elemental composition of halophytes and pseudo-halophytes is related to salt-tolerance categories, eco-morphological types and respective taxonomic groups.

Salt tolerance mechanisms in three Irano-Turanian Brassicaceae halophytes relatives of Arabidopsis thaliana.

Salt tolerance mechanisms were studied in three Irano-Turanian halophytic species from the Brassicaceae (Lepidium latifolium, L. perfoliatum and Schrenkiella parvula) and compared with the glycophyte Arabidopsis thaliana. According to seed germination under salt stress, L. perfoliatum was the most tolerant species, while L. latifolium and S. parvula were rather susceptible. Contrastingly, based on biomass production L. perfoliatum was more salt sensitive than the other two species. In S. parvula biomass was increased up to 2.8-fold by 100 mM NaCl; no significant growth reduction was observed even when exposed to 400 mM NaCl. Stable activities of antioxidative defense enzymes, nil or negligible accumulation of superoxide anion and hydrogen peroxide, as well as stable membrane integrity in the three halophytes revealed that no oxidative stress occurred in these tolerant species under salt stress. Proline levels increased in response to salt treatment. However, it contributed only by 0.3‒2.0% to the total osmolyte concentration in the three halophytes (at 400 mM NaCl) and even less (0.04%) in the glycophyte, A. thaliana (at 100 mM NaCl). Soluble sugars in all three halophytes and free amino acids pool in S. parvula decreased under salt treatment in contrast to the glycophyte, A. thaliana. The contribution of organic osmolytes to the total osmolyte pool increased by salt treatment in the roots, while decreased in halophyte and glycophyte, A. thaliana leaves. Interestingly, this reduction was compensated by a higher relative contribution of K in the leaves of the halophytes, but of Na in A. thaliana. Taken together, biomass data and biochemical indicators show that S. parvula is more salt tolerant than the two Lepidium species. Our data indicate that L. latifolium, as a perennial halophyte with a large biomass, is highly suitable for both restoration of saline habitats and saline agriculture.

Ethnobotanical and ethnomedicinal studies in Baluchi tribes: A case study in Mt. Taftan, southeastern Iran.

ETHNOBOTANICAL RELEVANCE: From ancient times, the applied use of herbs has been common among indigenous people throughout the world. The present survey is a regional ethnobotanical study of Baluchi tribes living in the Mt. Taftan area, Sistan and Baluchistan Province, southeastern Iran. The aim of this study was to document all traditional knowledge and analyze the medicinal plants used in area and also to identify significant plant species for future pharmacological study. MATERIALS AND METHODS: Local knowledge was obtained through semi structured and open interviews, in which 51 informants were interviewed. Data were analyzed with Informant Agreement Relative (IAR) and Frequency of Citation (FC) indices. RESULTS: A total number of 106 taxa of medicinal plants were collected from ten villages from the surrounding plains and highlands of Mt. Taftan, out of 446 plant taxa collected or reported as native in the area. Most plants belong to the Irano-Turanian phytogeographical region in which Asteraceae (15%), Lamiaceae (11%), Fabaceae (8%), Rosaceae (7%), Apiaceae (7%) and Brassicaceae (5%) are those predominantly used. The regression analysis shows that families Apiaceae, Lamiaceae, Solanaceae and Rosaceae are more highly used as medicinal than species rich families such as Asteraceae and Fabaceae, which are the richest families in the Iranian flora. The highest FC was recorded for Artemisia spp. (41) and Berberis integerrima (40). The highest IAR Index was obtained for stings (0.86), followed by disorders in the circulatory system (0.7), dental problems (0.70) and injuries (0.69). Comparing our data with major ethnobotanical references in Iran revealed that medicinal applications of 34 taxa have not been cited, including Hyoscyamus malekianus, a local endemic plant using for ailments of toothache and worms. The toxicity of the endemic Semenovia suffruticosa is also reported. CONCLUSION: As a result of this study we conclude that Taftan area harbours many plant species for which indigenous knowledge provides a background of medicinal importance. The high percentage of medicinal plants proportional to the native flora is 23.8%, compared to the world percentage of 17.1%, is an indication of the rich knowledge and relationship of isolated Baluchi tribes living in Mt. Taftan to the local flora growing in their surroundings. This rich knowledge should be highly regarded as a cultural and ethnobotanical heritage. Furthermore, ethnobotanical results show some weak interrelation between Baluchi tribes living in Iran and Pakistan, probably because of a different flora and/or unfavourable environmental conditions and perhaps local conflicts which might have reduced active cultural exchange.

Structural and physiological analyses in Salsoleae (Chenopodiaceae) indicate multiple transitions among C3, intermediate, and C4 photosynthesis.

In subfamily Salsoloideae (family Chenopodiaceae) most species are C4 plants having terete leaves with Salsoloid Kranz anatomy characterized by a continuous dual chlorenchyma layer of Kranz cells (KCs) and mesophyll (M) cells, surrounding water storage and vascular tissue. From section Coccosalsola sensu Botschantzev, leaf structural and photosynthetic features were analysed on selected species of Salsola which are not performing C4 based on leaf carbon isotope composition. The results infer the following progression in distinct functional and structural forms from C3 to intermediate to C4 photosynthesis with increased leaf succulence without changes in vein density: From species performing C3 photosynthesis with Sympegmoid anatomy with two equivalent layers of elongated M cells, with few organelles in a discontinuous layer of bundle sheath (BS) cells (S. genistoides, S. masenderanica, S. webbii) > development of proto-Kranz BS cells having mitochondria in a centripetal position and increased chloroplast number (S. montana) > functional C3-C4 intermediates having intermediate CO2 compensation points with refixation of photorespired CO2, development of Kranz-like anatomy with reduction in the outer M cell layer to hypodermal-like cells, and increased specialization (but not size) of a Kranz-like inner layer of cells with increased cell wall thickness, organelle number, and selective expression of mitochondrial glycine decarboxylase (Kranz-like Sympegmoid, S. arbusculiformis; and Kranz-like Salsoloid, S. divaricata) > selective expression of enzymes between the two cell types for performing C4 with Salsoloid-type anatomy. Phylogenetic analysis of tribe Salsoleae shows the occurrence of C3 and intermediates in several clades, and lineages of interest for studying different forms of anatomy.

The molecular phylogeny of Matthiola R. Br. (Brassicaceae) inferred from ITS sequences, with special emphasis on the Macaronesian endemics.

Matthiola (Brassicaceae) is a genus that is widespread in the Mediterranean and Irano-Turanian regions and includes two species that are endemic to the archipelagos of Madeira and the Canaries in Macaronesia, which is an insular oceanic hotspot of biodiversity harboring many radiating endemic plant lineages. Sequence analyses of the nuclear ITS-1 and ITS-2 regions in a comprehensive geographical sample of Matthiola, encompassing all the endemic Macaronesian populations known to date, suggest independent Mediterranean and NW African origins of the taxa in Madeira and the Canaries, respectively. These molecular data reveal a complex evolutionary landscape that converges with morphological analyses in the recognition of two new Madeiran species. The data also suggest that the Canarian infra-specific endemic taxa described thus far have high (but non-diagnostic) levels of morphological and genetic diversity, and should be included in the single endemic Matthiola bolleana. In agreement with earlier investigations that revealed a high genetic differentiation between the populations of Matthiola in Fuerteventura and Lanzarote, our phylogeny supports independent founder events from the same mainland congener to either island. The consistently derived position of the Moroccan populations within a mostly Canarian clade suggests a further back-colonization of the continent. Notably, the ITS sequence resolution offered by Matthiola is higher than that found in many of the radiating Canarian endemic lineages for which molecular phylogenetic studies abound. Hence, our research discovers largely unexplored pathways to understand plant diversification in this oceanic insular hotspot through the investigation of non-speciose endemics.

Does Bienertia cycloptera with the single-cell system of C(4) photosynthesis exhibit a seasonal pattern of delta (13)C values in nature similar to co-existing C (4) Chenopodiaceae having the dual-cell (Kranz) system?

Family Chenopodiaceae is an intriguing lineage, having the largest number of C(4) species among dicots, including a number of anatomical variants of Kranz anatomy and three single-cell C(4) functioning species. In some previous studies, during the culture of Bienertia cycloptera Bunge ex Boiss., carbon isotope values (delta(13)C values) of leaves deviated from C(4) to C(3)-C(4) intermediate type, raising questions as to its mode of photosynthesis during growth in natural environments. This species usually co-occurs with several Kranz type C(4) annuals. The development of B. cycloptera morphologically and delta(13)C values derived from plant samples (cotyledons, leaves, bracts, shoots) were analyzed over a complete growing season in a salt flat in north central Iran, along with eight Kranz type C(4) species and one C(3) species. For a number of species, plants were greenhouse-grown from seeds collected from the site, in order to examine leaf anatomy and C(4) biochemical subtype. Among the nine C(4) species, the cotyledons of B. cycloptera, and of the Suaeda spp. have the same respective forms of C(4) anatomy occurring in leaves, while cotyledons of members of tribe Caroxyloneae lack Kranz anatomy, which is reflected in the delta(13)C values found in plants grown in the natural habitat. The nine C(4) species had average seasonal delta(13)C values of -13.9 per thousand (with a range between species from -11.3 to -15.9 per thousand). The measurements of delta(13)C values over a complete growing season show that B. cycloptera performs C(4) photosynthesis during its life cycle in nature, similar to Kranz type species, with a seasonal average delta(13)C value of -15.2 per thousand.

Occurrence and forms of Kranz anatomy in photosynthetic organs and characterization of NAD-ME subtype C4 photosynthesis in Blepharis ciliaris (L.) B. L. Burtt (Acanthaceae).

Blepharis (Acanthaceae) is an Afroasiatic genus comprising 129 species which occur in arid and semi-arid habitats. This is the only genus in the family which is reported to have some C(4) species. Blepharis ciliaris (L.) B. L. Burtt. is a semi-desert species with distribution in Iran, Oman, and Pakistan. Its form of photosynthesis was investigated by studying different organs. C(4)-type carbon isotope composition, the presence of atriplicoid type Kranz anatomy, and compartmentation of starch all indicate performance of C(4) photosynthesis in cotyledons, leaves, and the lamina part of bracts. A continuous layer of distinctive bundle sheath cells (Kranz cells) encircle the vascular bundles in cotyledons and the lateral vascular bundles in leaves. In older leaves, there is extensive development of ground tissue in the midrib and the Kranz tissue becomes interrupted on the abaxial side, and then becomes completely absent in the mature leaf base. Cotyledons have 5-6 layers, and leaves 2-3 layers, of spongy chlorenchyma beneath the veins near the adaxial side of the leaf, indicating bifacial organization of chlorenchyma. As the plant matures, bracts and spines develop and contribute to carbon assimilation through an unusual arrangement of Kranz anatomy which depends on morphology and exposure to light. Stems do not contribute to carbon assimilation, as they lack chlorenchyma tissue and Kranz anatomy. Analysis of C(4) acid decarboxylases by western blot indicates B. ciliaris is an NAD-malic enzyme type C(4) species, which is consistent with the Kranz cells having chloroplasts with well-developed grana and abundant mitochondria.

Structural, biochemical, and physiological characterization of photosynthesis in two C4 subspecies of Tecticornia indica and the C3 species Tecticornia pergranulata (Chenopodiaceae).

Among dicotyledon families, Chenopodiaceae has the most C(4) species and the greatest diversity in structural forms of C(4). In subfamily Salicornioideae, C(4) photosynthesis has, so far, only been found in the genus Halosarcia which is now included in the broadly circumscribed Tecticornia. Comparative anatomical, cytochemical, and physiological studies on these taxa, which have near-aphyllous photosynthetic shoots, show that T. pergranulata is C(3), and that two subspecies of T. indica (bidens and indica) are C(4) (Kranz-tecticornoid type). In T. pergranulata, the stems have two layers of chlorenchyma cells surrounding the centrally located water storage tissue. The two subspecies of T. indica have Kranz anatomy in reduced leaves and in the fleshy stem cortex. They are NAD-malic enzyme-type C(4) species, with mesophyll chloroplasts having reduced grana, characteristic of this subtype. The Kranz-tecticornoid-type anatomy is unique among C(4) types in the family in having groups of chlorenchymatous cells separated by a network of large colourless cells (which may provide mechanical support or optimize the distribution of radiation in the tissue), and in having peripheral vascular bundles with the phloem side facing the bundle sheath cells. Also, the bundle sheath cells have chloroplasts in a centrifugal position, which is atypical for C(4) dicots. Fluorescence analyses in fresh sections indicate that all non-lignified cell walls have ferulic acid, a cell wall cross-linker. Structural-functional relationships of C(4) photosynthesis in T. indica are discussed. Recent molecular studies show that the C(4) taxa in Tecticornia form a monophyletic group, with incorporation of the Australian endemic genera of Salicornioideae, including Halosarcia, Pachycornia, Sclerostegia, and Tegicornia, into Tecticornia.

Flowers of Bienertia cycloptera and Suaeda aralocaspica (Chenopodiaceae) complete the life cycle performing single-cell C4 photosynthesis.

Leaves and cotyledons of the terrestrial C4 plants, Bienertia cycloptera Bunge ex Boiss. and Suaeda aralocaspica (Bunge) Freitag & Schütze (Chenopodiaceae), accomplish C4 photosynthesis within individual chlorenchyma cells: each species having a unique means of intracellular spatial partitioning of biochemistry and organelles. In this study the chlorenchyma tissue in flowers and stems of these species was investigated. Flowers have an outer whorl of green tepals with a layer of chlorenchyma cells, which are located on the abaxial side, exposed to the atmosphere. Anatomical, immunocytochemical, western blots and starch analyses show that the chlorenchyma cells in tepals are specialised for performance of single-cell C4 photosynthesis like that in leaves. In the tepals of B. cycloptera, chlorenchyma cells have a distinctive central cytoplasmic compartment, with chloroplasts which contain Rubisco, separated by cytoplasmic channels from a peripheral chloroplast-containing compartment, with phosphoenolpyruvate carboxylase (PEPC) distributed throughout the cytoplasm. In the tepals of S. aralocaspica, chlorenchyma cells have chloroplasts polarised towards opposite ends of the cells. Rubisco is found in chloroplasts towards the proximal end of the cell and PEPC is found throughout the cytoplasm. Also, green stems of B. cycloptera have a single layer of the specialised C4 type chlorenchyma cells beneath the epidermis, and in stems of S. aralocaspica, chlorenchyma cells are scattered throughout the cortical tissue with chloroplasts around their periphery, typical of C3 type chlorenchyma. During reproductive development, green flowers become very conspicuous, and their photosynthesis is suggested to be important in completion of the life cycle of these single-cell C4 functioning species.

Species having C4 single-cell-type photosynthesis in the Chenopodiaceae family evolved a photosynthetic phosphoenolpyruvate carboxylase like that of Kranz-type C4 species.

Spatial and temporal regulation of phosphoenolpyruvate carboxylase (PEPC) is critical to the function of C(4) photosynthesis. The photosynthetic isoform of PEPC in the cytosol of mesophyll cells in Kranz-type C(4) photosynthesis has distinctive kinetic and regulatory properties. Some species in the Chenopodiaceae family perform C(4) photosynthesis without Kranz anatomy by spatial separation of initial fixation of atmospheric CO(2) via PEPC from C(4) acid decarboxylation and CO(2) donation to Rubisco within individual chlorenchyma cells. We studied molecular and functional features of PEPC in two single-cell functioning C(4) species (Bienertia sinuspersici, Suaeda aralocaspica) as compared to Kranz type (Haloxylon persicum, Salsola richteri, Suaeda eltonica) and C(3) (Suaeda linifolia) chenopods. It was found that PEPC from both types of C(4) chenopods displays higher specific activity than that of the C(3) species and shows kinetic and regulatory characteristics similar to those of C(4) species in other families in that they are subject to light/dark regulation by phosphorylation and display differential malate sensitivity. Also, the deduced amino acid sequence from leaf cDNA indicates that the single-cell functioning C(4) species possesses a Kranz-type C(4) isoform with a Ser in the amino terminal. A phylogeny of PEPC shows that isoforms in the two single-cell functioning C(4) species are in a clade with the C(3) and Kranz C(4) Suaeda spp. with high sequence homology. Overall, this study indicates that B. sinuspersici and S. aralocaspica have a C(4)-type PEPC similar to that in Kranz C(4) plants, which likely is required for effective function of C(4) photosynthesis.

Differentiation of cellular and biochemical features of the single-cell C4 syndrome during leaf development in Bienertia cycloptera (Chenopodiaceae).

The terrestrial plant Bienertia cycloptera has been shown to accomplish C(4) photosynthesis within individual chlorenchyma cells by spatially separating the phases of carbon assimilation into distinct peripheral and central compartments. In this study, anatomical, physiological, and biochemical techniques were used to determine how this unique compartmentation develops. Western blots show ribulose-1,5-bisphosphate carboxylase (Rubisco) (chloroplastic) is present in the youngest leaves and increases during development, while levels of C(4) enzymes-pyruvate,Pi dikinase (chloroplastic), phosphoenolpyruvate carboxylase (PEPC) (cytosol), and NAD-malic enzyme (mitochondrial)-increase later in development. Immunolocalization confirmed this for Rubisco and PEPC. The youngest chlorenchyma cells have a central nucleus surrounded by monomorphic granal chloroplasts containing Rubisco. Later stages show progressive development of a central cytoplasmic compartment enriched with chloroplasts and mitochondria and of a peripheral cytoplasm with chloroplasts. A complex reticulum of connections between the compartments also developed and was characterized. δ(13)C isotope analyses show mature leaves have distinct C(4)-type isotope composition, while the composition in younger leaves is "C(4)-like." Based on the results, this form of single-cell C(4) photosynthesis develops from a common pool of organelles through partitioning to separate compartments, and the development of biochemically and ultrastructurally dimorphic chloroplasts.

Essential oils from two endemic species of Apiaceae from Iran.

The composition of essential oils of Leutea glaucopruinosa (Rech.f.) Akhani & Salimian comb. nov., and Zeravschania (Boiss. & Hausskn.) Salimian & Akhani comb. nov. were analysed by GC-MS. 49 compounds are identified in the former and 33 compounds in the latter, comprising a total of 76 compounds in both species. Both species were originally described under Peucedanum, which are transferred in this paper into Leutea and Zeravschania, respectively. The chemical compounds of the essential oils show that there are only seven common compounds between two species. The major compounds of L. glaucopruinosa are mostly monoterpene hydrocarbons and oxygenated monoterpenes, in which alpha-pinene (31.5%), sabinene (9.7%), beta-pinene (9.2%), exo-fenchyl acetate (4.5%) are dominant. In Z. pastinacifolia sesquiterpene hydrocarbons and phenylpropanoids dominate with beta-bisabolene (37.3%), 3,1-butyl-1,2-dimethoxy benzene (14.9%), 10,11-dimethylbicyclo[6.3.0]undec-(8)-en-9-one (12.9%), 4-t-butyl-1,2-dimethoxy benzene (6.8%), (E)-asarone (5.1%) and elemicine (4.1%) as major compounds.