Apical and basal auxin sources pattern shoot branching in a moss

Shoot branching mechanisms where branches arise in association with leaves – referred to as lateral or axillary branching – evolved by convergence in the sporophyte of vascular plants and the gametophyte of bryophytes, and accompanied independent events of plant architectural diversification. Previously, we showed that three hormonal cues, including auxin, have been recruited independently to co-ordinate branch patterning in flowering plant leafy shoots and moss gametophores (Coudert, Palubicki et al., 2015). Moreover, auxin-mediated apical dominance, which relies on local auxin production, has been proposed as a unifying molecular regulatory mechanism of branch development across land plants. Whilst our previous work in the moss Physcomitrium patens has gathered indirect evidence supporting the notion that auxin synthesized in gametophore apices regulates branch formation at a distance, direct genetic evidence for a role of auxin biosynthesis in gametophore branching control is still lacking. Here, we show that gametophore apex decapitation promotes branch emergence through massive and rapid transcriptional reprogramming of auxin-responsive genes and altering auxin biosynthesis gene activity. Specifically, we identify a subset of P. patens TRYPTOPHAN AMINO-TRANSFERASE (TAR) and YUCCA FLAVIN MONOOXYGENASE-LIKE (YUC) auxin biosynthesis genes expressed in apical and basal regions of the gametophore, and show that they are essential for branch initiation and outgrowth control. Our results demonstrate that local auxin biosynthesis coordinates branch patterning in moss and thus constitutes a shared and ancient feature of shoot architecture control in land plants.

Chiastocaulon raetzelii (Marchantiophyta, Plagiochilaceae), a new species from New Caledonia

The new liverwort species Chiastocaulon raetzelii is described from New Caledonia. Chiastocaulon raetzelii is characterized by very fragile, caducous leaves, stems therefore often becoming completely denuded of leaves; only bract leaves of the androecia are permanent and often the only ones remaining on the stem. Plants are minute with leafy shoots to 1 mm wide. Leaves on leafy shoots are arranged in opposing pairs, they are obovate-truncate to spathulate, with 3–7 teeth per leaf, teeth are filiform, consisting of long rectangular cells, and occupy about 1/3 to 1/4 of the entire leaf length. The species is compared to C. oppositum and C. geminifolium, which are the most similar morphologically.

REGENERATION CAPACITY OF NARROW-LOCALIZED ENDEMIC SPECIES Dianthus hypanicus Andrz. in vitro

Development of effective technology of rare and endangered plant species mass reproduction in vitro is one of the urgent nowadays tasks. Diantus hypanicus Andrz. of the Caryophyllaceae Juss. family belongs to this group of plants. It is an endemic, narrow-localized species listed in the Red Book of Ukraine, the European Red List and the Annex to the Berne Convention. Prospects for the conservation of this species are associated with the study of its viability and require the development of effective reproduction methods. Aim. The purpose of the experiment was to determine the effect of different growth regulators concentrations on the D. hypanicus explants regenerative capacity during in vitro propagation. Methods. For the experiment the seed were used collected from plants of natural habitats and sown on a hormone-free nutrient medium according to the recipe of Murashige and Skoog. For 12–15 days, 4–6 cm long seedlings were obtained which were transferred to nutrient media modified with the content of growth-regulating substances: BAP 0.5–2.0 mg / l, IBA 0.01 mg / l and IAA 0.1 mg / l. Results. Initiation of adventitious buds with subsequent shoot formation was observed for 12–16 days. Each variant plants differed in number, growth activity and intensity, morphometric parameters. After 35–40 days from the explant introduction, conglomerates with well-developed leafy shoots were formed. It was found that, when modifying nutrient media with growth regulators BAP, IBA, IAA of different concentrations, D. hypanicus explants were actively undergoing regeneration processes of different intensity. Conclusions. It was proved that high ability to regenerate was the characteristic of explants cultured on a nutrient medium modified by the addition of BAP – 0.5 mg / l and IAA – 0.1 mg / l, where, on average, 18 ± 0.24 shoots of 2.42 ± 0.17 cm long were formed with a net reproduction of 19.06 ± 0.14. Shoots with 3.0–5.0 pairs of leaves that reached 3.5–6.0 cm were selected and transferred to nutrient media for rooting. Less developed shoots were planted on nutrient media for further reproduction. The next stage of the study is aimed at modifying nutrient media to achieve explants rhizogenesis and obtain a large number of plants necessary for the preservation of this endemic narrow-localized species in culture with subsequent repatriation to natural places of growth.

Successive applications of gibberellic acid to reduce flowering of 'Montenegrina' mandarin in alternate bearing

The objective of this work was to evaluate the number of successive applications of gibberellic acid (GA3), during the autumn-winter period, for its effect on the reduction of flowering, in the subsequent spring after periods of low fruit load (off-year), in 'Montenegrina' mandarin trees (Citrus deliciosa). Sequential applications at 40 mg L-1 GA3 were tested from one to four times, at 21-day intervals, beginning in the end of May. The experiment was carried out in a randomized complete block design, with four treatments and a control, four replicates, and one plant per experimental unit. Flowering, sprouting, types of shoots, fruit set, and fruit diameter were evaluated. The fruit set increases exponentially with the reduction of flowering intensity. The use of GA3 in two, three, or four sequential applications, from May to June, May to July, and from May to August, at 21-day intervals, reduces the intensity of flowering and sprouting of alternate bearing plants in the subsequent spring, increasing mixed shoots and reducing floral shoots. The use of four sequential applications of 40 mg L-1 GA3 promotes a great increase in the frequency of single flower terminal leafy shoots and favors the increase of fruit fixation and size.

COMPARISON OF VAPOR-PHASE ACETIC ACID AND VINEGAR EFFECTIVENESS IN MAINTAINING QUALITY OF SWEET BASIL (OCIMUM BASILICUM LINN.)

Leafy shoots of sweet basil (Ocimum basilicum Linn.) were exposed to the vapor of either dilute acetic acid (AA) or of upland rice vinegar (URV) – both solutions were diluted to contain 4% of acetic acid – for 10 min and stored at 12°C. The sweet basil exposure to AA had a 16% increase in shelf life and those exposures to URV 35% increase compare to the control. There were no significant differences in fresh weight loss during storage between the AA and URV but both had significantly lower fresh weight losses than the control. The chlorophyll content of both AA and URV were significantly higher than the control. The radical scavenging was significantly higher in the URV than in the AA and the control. The electrolyte leakage was both significantly lower in the URV than in the AA and the control. The occurrence of lipid peroxidation was similar in both the AA and URV, and both were significantly lower than in the control. These results indicate URV has potential as an effective way of raising quality and extending postharvest storage of sweet basil shoots.

POST-HARVEST PHYSIOLOGY AND AGING OF CUT FLOWERS

The review paper discusses the problems of postharvest physiology associated with maintaining the quality of floriculture products. Petals are an excellent model system for studying the aging process and programmed death of plant cells. The authors outline achievements of molecular biology and epigenetics in studying the regulation mechanisms of aging and cell death, and state their role in the loss of the decorative qualities of flowers. The study of water metabolism, the activity of antioxidant systems, and the stability of cell membranes has shown that their changes begin in the early stages of flower development and precede visible signs of the loss of decorative qualities.Common features and differences in the aging dynamics of leaves and petals are noted. Maintaining the water status of leafy shoots is an important factor in maintaining the quality of flower products. Using the inhibitory method (STS, 1-MCP) the authors have shown that ethylene is a trigger of the aging process only in a limited range of plants. Many modern hybrids of garden cloves that are typically considered ethylene sensitive are not sensitive to ethylene. In alstroemeria, lilies,and freesia, ethylene is involved only in the final stage of flower aging and petal fall. The threshold value of the activity of hydrolytic enzymes that ensure the mobilization of proteins and lipids can be a leading factor in starting the aging mechanisms. Ethylene only increases the efficiency of using nutrients to form seeds and fruits. Research based on physiological, biochemical, and genetic approaches should provide a clearer picture of aging and its regulation. Studyig the role of ROS and antioxidant systems can be quite promising for assessing the common and different signaling pathways in different parts of a plant. 5-sulfosalicylic acid, which increases the activity of antioxidant systems, can gain its rightful place in a series of products to slow down the aging of cut flowers, especially in ethylene-insensitive species.

IN-PLANTA TRANSFORMATION METHOD MEDIATED WITH Agrobacterium tumefaciens FOR T-DNA TRANSFER IN TABLE GRAPE (Vitis vinifera L.)

The aim of the research is to investigate a simple method of in planta transformation method for T-DNA transfer in table grape. The T-DNA harbored the S0SPS1 gene under the control of promoter of the 35S CaMV from the Cauliflower Mosaic Virus and contained the NPTII gene, a kanamycin-resistant gene as a selectable marker for transformant selection. Six-month plants originated from cuttings were used as target plants. We explored two methods of in planta transformation, namely ”dipping” and “sweeping”. For both methods, the leaves of the target plants were removed and those of shoots without leaves were used as the target of transformation. In the “dipping method”, those shoots were dipped with the agrobacterial suspension for 60 seconds. However, for the “sweeping method”, the scars (the spots where leaves were removed) were swept with agrobacterial suspension using a cotton bud. Those treated non-leafy-shoots (from both methods) then were grown to be leafy shoots. Those leafy shoots then were cut and transplanted into the soil and grown to be a whole plant. The leaves of those plants then were taken as samples for DNA extraction and PCR using primers of NPTII gene (Forward: 5’-GTCATCTCACCTTCCTCCTGCC-3’; Reverse: 5’ GTCGCTTGGTCGGTCATTTCG-3’) with expected amplified band of 550 bp. We found that only the “sweeping method” plants amplified the 550 bp bands, while those of the “dipping method” did not. We suggest that the T-DNA was successfully integrated into the genome of plants treated with the “sweeping method” but not with the “dipping method”. Leaf sugar content (oBrix) of PCR-positive vines was higher than those of the wild-type vines, ensuring the integration of the T-DNA into the plant genome.

Juglans × intermedia Carr. – an interesting finding in the Židlochovice Forest Enterprise

A grown-up specimen of Juglans ×intermedia Carr. walnut was accidentally found in the stand of black walnut (Juglans nigra L.) in the Židlochovice Forest Enterprise in the forest district Velký Dvůr, Stand No. 224 D10. The tree was photographed, leafy shoots and fruits were sampled for later analyses. The paper brings a description of growth habit, rough bark, morphology of leaves, current year shoots and fruits. Discussed are dissimilarities from the parental species (J. nigra and J. regia L.).

BIOACTIVE COMPONENTS OF ETHEREAL EXTRACT OF WOOD GREENING SEA BUCKTHORN HIPPOPHAE RHAMNOIDES L.

The composition of lipophilic components of sea buckthorn leafy shoots, a large tonnage waste in the production of sea buckthorn oil and during renewing the cultural plantings of sea buckthorn, was studied. Tert-butyl methyl ether (TBME) was used as an extraction solvent for raw materials having all the advantages of diethyl ether, but devoid of its disadvantages. It does not form peroxides and does not create increased gas content due to the higher boiling point. The chemical composition of the TBME extract of sea buckthorn leafy shoots was studied by gas chromatography–mass-spectrometry and high-performance liquid chromatography. Seventy-four neutral and thirty-eight acidic components, including polyprenols, dolichols, triterpene alcohols and acids, sterols, were identified. TBME as an extragent provides more high yields of bioactive triterpenoic acids and diols including uvaol, eritrodiol and betulin in comparison with n-hexane. These compounds can increase some useful properties of obtained extract.

Leafy shoots and pollen cones of conifers from the Middle Jurassic deposits of the Irkutsk Coal Basin

Among the numerous remains of the Jurassic conifers in the Irkutsk Coal Basin, several types of leafy shoots are distinguished. One type is characterized by the leaves with numerous veins. These remains were described as Podozamites irkutensis N. Nosova et Kiritch. (Nosova et al., 2017). The leaves of other types have a midvein. These leafy shoots are attributed to several taxa: Marskea sp. nov. (in press), Elatocladus falcatus (Heer) Prynada, E. heeriana N. Nosova et Kiritch., sp. nov., Elatocladus sp. and Pagiophyllum sp. Elatocladus falcatus (Heer) Prynada, 1962 (=Elatides falcata Heer, 1976) was described from the deposits of the lower subformation of the Prisayan Formation (the Aalenian) of the Ust’-Baley locality. An epidermal structure of the Elatocladus falcatus leaves is unknown. Here we designate the lectotype for E. falcatus. We have studied the leaf epidermal structure of the leafy shoots from the upper subformation of the Prisayan Formation (the Aalenian-Bajocian) in the localities Topka and Vladimirovka. Based on the morphological and epidermal features, we describe a new species Elatocladus heeriana. The shoots of E. heeriana have with helically arranged leaves. The leaves are sessile and dorsoventrally flattened, linear, lanceolate to falcate, with the tip curving toward the apex of the stem, with the broad and decurrent base and acute apex. The leaves are hypostomatic. They are characterized by straight to undulating anticlinal cell walls of the abaxial epidermis near the leaf edge and base. Stomata are arranged in two narrow bands, orientated transversely to irregularly. Subsidiary cells of the stomatal complexes are without papillae. Rare fragments of the Pagiophyllum sp. shoots were found in the deposits of the upper subformation of the Prisayan Formation (the Aalenian–Bajocian) in the localities Olkha and Vladimirovka. Their leaves are falcate, with a median keel on the abaxial side. The bad preservation of the cuticle did not allow us to study the epidermal pattern in details. Stomata are arranged in the bands, orientated irregularly. Subsidiary cells of the stomatal complexes are without papillae. One pollen cone (microstrobilus), attached presumably to the E. heeriana shoot, and several detached pollen cones of Schidolepium gracile Heer (1880) were found. The pollen cones are elongated, with numerous imbricate, helically arranged and dorsoventrally flattened microsporophylls. Sterile part of the microsporophyll expands to the distal lamina with acute apex. Some microsporophylls near the cone base are oval with rounded apex. The numerous microsporangia are visible in the apical part of the mature pollen cone, but a distal lamina of the microsporophylls often is indistinct here. Microsporangia (5–7 per microsporophyll) are elongated, fusiform. Pollen grains are spherical, nonsaccate, with the rugulate-perforate surface, apertures are invisible. The emended diagnosis is provided for the type species S. gracile, as well as the lectotype is designated.