Formation of phenolic compounds in the roots of <Emphasis Type="Italic">Hedysarum theinum</Emphasis> cultured in vitro

A steadily growing culture of genetically transformed roots of a valuable medicinal Altaic plant Hedysarum theinum Krasnob. was established using a Ri-plasmid (pRi) T-DNA of A4 wild strain of Agrobacterium rhizogenes. The composition of secondary substances accumulated in the in vitro roots and the roots of H. theinum intact seedlings was investigated. Isoflavonoids were found to represent by their main low-molecular metabolites. Preparative HPLC made it possible to isolate four substances from the methanolic extract of H. theinum cultured roots. Using ¹H- and ¹³C-NMR-spectrometry, these substances were identified as formononetin, ononin (formononetin glycoside), malonyl ononin, and texasin glucoside. The qualitative composition of secondary metabolites of the genetically transformed roots and the roots of H. theinum seedlings was essentially the same, except that malonyl ononin was not found in the latter. The technique of producing artificial seeds on the basis of H. theinum roots cultured in vitro was tested, and the possibility of their use as a rhizogenic inoculum was substantiated. The culture of H. theinum roots is considered as a potential source of ecologically pure raw material for medicinal preparations, and the artificial seeds with root inoculum are a promising vehicle for propagation and conservation of this valuable plant.     

Anatomical and micromorphological studies on <Emphasis Type="Italic">Teucrium</Emphasis> sect. <Emphasis Type="Italic">Isotriodon</Emphasis> (Lamiaceae) in Turkey with a taxonomic note

In this study, the anatomical features of the leaf and stem, besides the nutlet characteristics of some Teucrium sect. Isotriodon (Lamiaceae) taxa in Turkey, T. montbretii Betham subsp. montbretii, T. montbretii subsp. pamphylicum P. H. Davis, T. odontites Boiss. &; Bal., T. cavernarum P. H. Davis, T. antitauricum T. Ekim, along with an isolated population of T. montbretii (T. montbretii subsp.) were investigated. The anatomical studies revealed that the taxa share generally similar anatomical characters, such as thicker upper leaf cuticles and larger upper leaf epidermal cells compared to lower ones and diacytic to anomocytic stomata on the leaves. However, the portion of the mesophyll occupied by palisade parenchyma and the occurrence of mucilage cells in leaf epidermis shows difference among the taxa. Furthermore, the studied taxa have general stem characteristics of the Lamiaceae family, except for having poorly developed collenchyma at the corners. With the amphistomatic leaves and developed sclerenchymatic tissue in the leaf median vein, T. cavernarum is seperated from the other taxa. Trichome types on the vegetative organs and nutlet shape and sculpturing are generally the same or similar in the studied taxa, but trichomes on the nutlets are different among them. Based on nutlet characteristics and some morphological ones, it was revealed that the isolated population of T. montbretii represent a new subspecies, T. monbretii subsp. yildirimlii M.Dinç &; S.Do?u subsp. nov.     

The contribution of foliar micromorphology and anatomy to the circumscription of species within the <Emphasis Type="Italic">Chusquea ramosissima</Emphasis> informal group (Poaceae,Bambusoideae, Bambuseae)

Chusquea is a diverse but monophyletic genus of Neotropical woody bamboos from primarily montane forests that comprises four well-supported lineages: subg. Magnifoliae, subg. Platonia, subg. Rettbergia, and the Euchusquea clade (comprising subg. Swallenochloa and subg. Chusquea). However, the relationships among clades or taxa within the Euchusquea clade inferred from molecular data are mostly not congruent with those inferred from morphological evidence, consequently limiting our ability to understand species relationships. In this study we generated foliar micromorphological and anatomical data for the Chusquea ramosissima informal group (Chusquea ramosissima, C. tenella, and C. tenuiglumis), and for the putative new species from Bolivia in this group, in order to test the value of these types of data for defining species and to seek potential synapomorphies for this group. Our results demonstrate that epidermal features, mainly with regard to the stomatal apparatus, proved to be more valuable in distinguishing species than anatomical characters. The presence of horizontally elongated silica cells over the veins and adaxial arm cells with invaginations from the abaxial side was shared by all the studied species but is not unique to this group. The type of trichomes, shape of silica bodies, type of arm cells, and midrib structure may be useful to lesser degree. All four species exhibited intraspecific variation in development of the papillae on the long cells. Support for the recognition of the new species from Bolivia is provided by micromorphological characters. An identification key based on leaf blade features is provided for the four studied species.     

Anatomy,pollen, and chromosomes of <Emphasis Type="Italic">Adenoa</Emphasis> (Turneraceae), a monotypic genus endemic to Cuba

The monotypic genus Adenoa is endemic to Cuba. Its name alludes to the presence of minute glands on the petal margin, identified in the present study as lachrymiform colleters. Here we describe the morphological, anatomical, palynological, and chromosome features that characterize Adenoa cubensis. The indumentum of Adenoa consists only of stellate trichomes. Unlike many species of the new world genera Piriqueta and Turnera, Adenoa lacks glandular hairs and extrafloral nectaries. Adenoa, Piriqueta, and Turnera share the presence of standard, sessile, and lachrymiform colleters. The leaves of Adenoa have xeromorphic features, which include entire, revolute blade margins, an adaxial hypodermis, and stomata restricted to the abaxial surface. The chromosome number is 2n?=?14, which is probably the ancestral number of the family. Adenoa chromosomes are similar in size to those of Turnera, and are larger than those of Piriqueta. Using the available data, we discuss relationships among the new world genera of Turneraceae.     

Iron supplementation promotes in vitro shoot induction and multiplication of <Emphasis Type="Italic">Baptisia australis</Emphasis>

C₄ plants can efficiently accumulate CO₂ in leaves and thus reduce wasteful oxygen fixation by the RuBisCO enzyme. Three C₄ enzymes, namely carbonic anhydrase (CA), phosphoenol pyruvate (PEPC) and pyruvate orthophosphate dikinase (PPDK), were over expressed in Oryza sativa L. ssp. indica var. Khitish under the control of green tissue specific promoters PD_54o, PEPC and PPDK, respectively. Integration of these genes was confirmed by Southern hybridization. The relative expression of PEPC, CA and PPDK were, respectively, 6.75, 6.57 and 3.6-fold higher in transgenic plants compared to wild type plants (control). Photosynthetic efficiency of the transgenic plants increased significantly along with a 12?% increase in grain yield compared to wild type plants. Compared to control plants, transgenic plants also showed phenotypic changes such as increased leaf blade size, root biomass, and plant height and anatomical changes such as greater leaf vein number, bundle sheath cells, and bulliform cells. Our findings indicate that the combined over expression of these three enzymes is an efficient strategy for incorporating beneficial physiological and anatomical features that will enable subsequent yield enhancement in C₃ rice plants.     

Fossil wood of <Emphasis Type="Italic">Betula erkovetskiensis</Emphasis> sp. nov. (Betulaceae) from the Miocene of the Erkovetskii Brown Coal Field,Amur Region,Russia

A new species, Betula erkovetskiensis Blokhina et O.V. Bondarenko (Betulaceae), from the deposits of the Sazanka Formation (upper Middle?Upper Miocene) of the Erkovetskii Brown Coal Field (Amur Region, Russia) is described based on anatomical features of fossil wood. The new species shows some wood anatomical characters of the extant birch subgenus Betula, B. davurica, B. nigra (section Dahuricae), and B. papyrifera (section Betula). Fossil wood of Betula is found in the Amur Region for the first time.     

Specific leaf area variations drive acclimation of <Emphasis Type="Italic">Cistus salvifolius</Emphasis> in different light environments

Cistus salvifolius L. is the most widely spread Cistus species around the Mediterranean basin. It colonizes a wide range of habitats growing from sea level to 1,800 m a.s.l., on silicolous and calcicolous soils, in sun areas as well as in the understory of wooded areas. Nevertheless, this species has been mainly investigated in term of its responsiveness to drought. Our aim was to understand which leaf traits allow C. salvifolius to cope with low-light environments. We questioned if biochemical and physiological leaf trait variations in response to a reduced photosynthetic photon flux density were related to leaf morphological plasticity, expressed by variations of specific leaf area (SLA) and its anatomical components (leaf tissue density and thickness). C. salvifolius shrubs growing along the Latium coast (41°43'N,12°18'E, 14 m a.s.l., Italy) in the open and in the understory of a Pinus pinea forest, were selected and the relationships between anatomical, gas exchange, chlorophyll (Chl) fluorescence, and biochemical parameters with SLA and PPFD variations were tested. The obtained results suggested long-term acclimation of the selected shrubs to contrasting light environments. In high-light conditions, leaf nitrogen and Chl contents per leaf area unit, leaf thickness, and Chl a/b ratio increased, thus maximizing net photosynthesis, while in shade photosynthesis, it was downregulated by a significant reduction in the electron transport rate. Nevertheless, the increased pigment-protein complexes and the decreased Chl a/b in shade drove to an increased light-harvesting capacity (i.e. higher actual quantum efficiency of PSII). Moreover, the measured vitality index highlighted the photosynthetic acclimation of C. salvifolius to contrasting light environments. Overall, our results demonstrated the morphological, anatomical, and physiological acclimation of C. salvifolius to a reduced light environment.     

A new <Emphasis Type="Italic">Heteropterys</Emphasis> (Malpighiaceae) from semideciduous forest,with notes on wood anatomy

This paper describes and illustrates Heteropterys serrata, a new species endemic to semideciduous forests associated with inselbergs in the state of Espírito Santo, Brazil. Morphological and wood anatomical traits of the new species are compared to those of other species of the Heteropterys Metallophyllis informal group. Based on wood anatomy, H. serrata and H. nitida (the most morphologically similar species) have different axial parenchyma, which is scarce paratracheal in H. nitida (and some other species of the Metallophyllis informal group) and aliform confluent in H. serrata. The most notable morphological and anatomical characters that distinguish the new species are the young hexagonal stems, the unusual widely serrate leaf margins and the aliform confluent axial parenchyma in the wood.     

Mutations in <Emphasis Type="Italic">CsPID</Emphasis> encoding a Ser/Thr protein kinase are responsible for round leaf shape in cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.)

Key message

Two round-leaf mutants, rl-1 and rl-2, were identified from EMS-induced mutagenesis. High throughput sequencing and map-based cloning suggested CsPID encoding a Ser/Thr protein kinase as the most possible candidate for rl-1. Rl-2 was allelic to Rl-1.

Abstract

Leaf shape is an important plant architecture trait that is affected by plant hormones, especially auxin. In Arabidopsis, PINOID (PID), a regulator for the auxin polar transporter PIN (PIN-FORMED) affects leaf shape formation, but this function of PID in crop plants has not been well studied. From an EMS mutagenesis population, we identified two round-leaf (rl) mutants, C356 and C949. Segregation analysis suggested that both mutations were controlled by single recessive genes, rl-1 and rl-2, respectively. With map-based cloning, we show that CsPID as the candidate gene of rl-1; a non-synonymous SNP in the second exon of CsPID resulted in an amino acid substitution and the round leaf phenotype. As compared in the wild type plant, CsPID had significantly lower expression in the root, leaf and female flowers in C356, which may result in the less developed roots, round leaves and abnormal female flowers, respectively in the rl-1 mutant. Among the three copies of PID genes, CsPID, CsPID2 and CSPID2L (CsPID2-like) in the cucumber genome, CsPID was the only one with significantly differential expression in adult leaves between WT and C356 suggesting CsPID plays a main role in leaf shape formation. The rl-2 mutation in C949 was also cloned, which was due to another SNP in a nearby location of rl-1 in the same CsPID gene. The two round leaf mutants and the work presented herein provide a good foundation for understanding the molecular mechanisms of CsPID in cucumber leaf development.

     

Fossil Wood of <Emphasis Type="Italic">Ulmus priamurica</Emphasis> sp. nov. (Ulmaceae) from the Miocene of the Erkovetskii Brown Coal Field,Amur Region,Russia

A new species, Ulmus priamurica sp. nov. (Ulmaceae), from the deposits of the Sazanka Formation (upper Middle–Upper Miocene) of the Erkovetskii Brown Coal Field (Amur Region, Russia) is described based on anatomical features of fossil wood. The new species shows some wood anatomical characters of the extant elms U. japonica and U. americana. Fossil wood of Ulmus was found in the Amur Region for the first time.     

Salt stress reveals differential physiological,biochemical and molecular responses in <Emphasis Type="Italic">T. monococcum</Emphasis> and <Emphasis Type="Italic">T. durum</Emphasis> wheat genotypes

Salt stress responses implicate a complex mechanism and differ from plant species to another. In this study, we analyzed the physiological, biochemical and molecular responses to salt stress of the diploid wheat (T. monococcum) and compared to the tetraploid wheat (T. durum). Our results showed that the diploid wheat cultivar (cv. Turkey) is relatively tolerant to different salt stress conditions than the tetraploid wheat cultivar (cv. Om Rabia3). This tolerance was manifested by significant germination, plant growth and uptake of water generating cell turgor and development. Moreover, total chlorophyll content was higher in the diploid wheat than that in the tetraploid wheat. The Na⁺ content in leaf blade of the cv. Om Rabia3 was significantly higher than that of the cv. Turkey, suggesting that the diploid cultivar accumulates less toxic sodium in the photosynthetic tissues. This mechanism could be explained by the recirculation of the toxic ions Na⁺ into the xylem sap by SOS1 protein, which coordinates with HKT-like proteins to reduce the accumulation of Na⁺ ions in leaf blade. Interestingly, the expression of the three genes SOS1, HKT and NHX was enhanced under salinity especially in leaf blade of the cv. Turkey. Moreover, this wheat cultivar induced the antioxidative enzymes CAT and SOD activity more efficiently than the other cultivar.     

Fossil wood of <Emphasis Type="Italic">Pinus priamurensis</Emphasis> sp. nov. (Pinaceae) from the Miocene deposits of the Erkovetskii Brown Coal Field,Amur Region

New species of the pine fossil wood, Pinus priamurensis sp. nov. (Pinaceae) from the Sazanka Formation (upper Middle Miocene–Upper Miocene) of the Erkovetskii Brown Coal Field (Amur Region) is described. The new species shares some wood anatomical features with modern species of the subsection Pinus (section Pinus, subgenus Pinus). This is the first record of fossil wood of Pinus in the Amur Region.     

Allelopathic Potential of <Emphasis Type="Italic">Koelreuteria bipinnata</Emphasis> var. <Emphasis Type="Italic">integrifoliola</Emphasis> on Germination of Three Turf Grasses

Allelopathy is very important for the scientific disposition of garden plants. To understand the allelopathic potential of Koelreuteria bipinnata Franch. var. integrifoliola, the germination of Agrostis tenuis Sibth., Festuca arundinacea Schreb. and Lolium perenne L. were determined under laboratory conditions. The results showed that root, stem and leaf aqueous extracts of K. bipinnata var. integrifoliola had allelopathic effects on all three turf grasses, and the allelopathic activity varied according to extract concentrations, test species, and extract sources. Lower extract concentrations did not affect or promoted the germination and initial seedling growth of turf grasses, but the highest concentrations almost had inhibitory effect. The order of allelopathic potentials of the three organs on germination of these receptors was root < stem < leaf. And at the highest concentration of leaf extract, the most strongly inhibition was found in A. tenuis, followed by F. arundinaces and then L. perenne. In addition, according to gas chromatography–mass spectrometry (GC–MS) analysis, the allelopathic potential compounds and their abundance in root, stem and leaf were obviously different. Therefore, the allelopathic compounds may responsible for allelopathy of K. bipinnata var. integrifoliola. These findings suggested that more attention should be paid to the leaf of K. bipinnata var. integrifoliola for the relative higher allelopathic effects.     

Anatomy and photosystem II activity of <Emphasis Type="Italic">in vitro</Emphasis> grown <Emphasis Type="Italic">Aechmea blanchetiana</Emphasis> as affected by 1-naphthaleneacetic acid

Auxins are one of the main regulators of in vitro plant growth and development. However, the mechanisms, by which auxins, such as 1-naphthaleneacetic acid (NAA), affect in vitro root and leaf anatomy and photosystem function, remain unclear. Accordingly, the aim of the present study was to analyze the effect of different NAA concentrations on the anatomy and photosynthetic performance of in vitro-propagated Aechmea blanchetiana and to determine whether such a treatment affects micropropagated plants after acclimatization. In vitro-established A. blanchetiana plants were transferred to culture media that contained 0, 2, 4, or 6 μM NAA, and after 50 d, they were transplanted into plastic seedling trays with a commercial substrate and cultivated for 60 d in a greenhouse. The plants were evaluated after a 50-d in vitro NAA exposure (growth traits, chlorophyll α fluorescence, and root and leaf anatomy) and after 60 d of acclimatization in the greenhouse (root and leaf growth). Changes induced by NAA in root anatomy might improve uptake of minerals and sugars from the medium, thereby increasing the in vitro growth. In the leaves, the lowest chlorenchyma thickness and sclerenchyma area were observed in plants grown without NAA, and NAA exposure also improved photosystem II activity. The highest ex vitro growth rate was observed for plants that were propagated with 4 μM NAA. Therefore, the use of NAA during in vitro propagation can improve the anatomical and physiological quality of A. blanchetiana plants, as well as to improve ex vitro transfer.     

Histological and cytological studies of plant infection by <Emphasis Type="Italic">Erysiphe euonymi</Emphasis>-<Emphasis Type="Italic">japonici</Emphasis>

Powdery mildew caused by Erysiphe euonymi-japonici (Eej) is an increasingly serious fungal disease on Euonymus japonicus that is an important ornamental plant. However, little is currently known about infection and pathogenesis of Eej on E. japonicus. Here, we report plant infection by Eej at the histological and cytological levels. Eej caused severe disease symptoms with white and snow-like colonies on leaf surfaces of E. japonicus. Microscopic observations were conducted continuously to define infection process of Eej on E. japonicus. Eej conidia germinated to produce appressorial germ tubes on leaf surfaces and formed irregular haustoria in plant epidermal cells at 6 h post-inoculation (hpi) and 12 hpi, respectively. After uptaking nutrients from host cells by haustoria, Eej formed numerous hyphae and extensive colonization on leaf surfaces at 96 hpi and finally produced abundant conidiophores and new conidia on leaf surfaces at 168 hpi. In addition, there was consistently a single nucleus in different Eej infection structures and haustorial development could be divided into three major stages, including formation of penetration peg, formation of haustorial neck and initial haustorium, and maturation of haustorium. These results provide useful information for further determination of Eej pathogenesis and finally controlling the disease.     

A betaine aldehyde dehydrogenase gene from <Emphasis Type="Italic">Ammopiptanthus nanus</Emphasis> enhances tolerance of <Emphasis Type="Italic">Arabidopsis</Emphasis> to high salt and drought stresses

YUCCA is an important enzyme which catalyzes a key rate-limiting step in the tryptophan-dependent pathway for auxin biosynthesis and implicated in several processes during plant growth and development. Genome wide analyses of YUCCA genes have been performed in Arabidopsis, rice, tomato, and Populus, but have never been characterized in soybean, one of the most important oil crops in the world. In this study, 22 GmYUCCA genes (GmYUCCA1-22) were identified and named based on soybean whole-genome sequence. Phylogenetic analysis of YUCCA proteins from Glycine max, Arabidopsis, Oryza sativa, tomato, and Populus euphratica revealed that GmYUCCA proteins could be divided into four subfamilies. Quantitative real-time RT-PCR (qRT-PCR) analysis showed that GmYUCCA genes have diverse expression patterns in different tissues and under various stress treatments. Compared to the wild type (WT), the transgenic GmYUCCA5 Arabidopsis plants displayed downward curling of the leaf blade margin, evident apical dominance, higher plant height, and shorter length of siliques. Our results provide a comprehensive analysis of the soybean YUCCA gene family and lay a solid foundation for further experiments in order to functionally characterize these gene members during soybean growth and development.