Secondary phloem traits in mature stems of Betula ermanii in stressful environments of volcanic activity

This research summarizes the results of study of structural peculiarities of Betula ermanii growing around Baransky Volcano close to the thermal Golubye Ozera. We have performed statistical analysis of parameters of the secondary phloem of multiyear shoots and stems and found some features tied to extreme environmental conditions. We have found that structural reaction of the secondary phloem of multiyear shoots and stems of B. ermanii to the extreme conditions of post-volcanic activity of Baransky Volcano manifests itself as changes in the geometry of the conductive elements and dilatation of the radial parenchyma in the non-conductive phloem. We believe these changes to be adaptive in nature due to the need for increased conductivity in volcanic landscapes.

Structural deviations in secondary phloem of young shoots of Spiraea beauverdiana near magma volcanoes

We performed a comparative analysis of the internal structure of the secondary phloem of one, two and three-year-old stems of Spiraea beauverdiana growing in extreme conditions of solfataric fields of Golovnin Volcano caldera and Mendeleyev Volcano and in normal conditions. The combination of environmental factors in conditions of solfataric activity, such as high temperatures in the soil and in the near-surface air, as well as saturation with gases toxic to plants, rare elements accumulating in the nearby substrate, and lack of soil moisture, interfere with normal phellogen and cambium activity. Deviations from the normal structure involve changes in the following parameters of the internal structure of a year-old stem of S. beauverdiana. Secondary phloem parameters in the studied habitats are normal, except for the length of the segments of sieve tubes, the height of single-row rays, the length of parenchymal girder; these are shorter in S. beauverdiana stems from volcanos. At two and three years of age in volcanic conditions we see reduction in the width of the secondary phloem (both conductive and non-conductive) and the diameter of the segments of sieve tubes. In samples from Golovnin Volcano we see reduction in tangential diameter, while in the samples from Mendeleyev Volcano it’s the radial diameter. We also see reduction in the height of multiple-row rays. At that age we see changes in the structure of the radial parenchyma; namely, we find no double-row rays in samples from Golovnin Volcano caldera. One of the signs of impact of volcanic activity on the bark structure is development of non-specific anomalies in the internal structure of the S. beauverdiana bark, namely, in the outer bark, or in deeper levels, such as the secondary phloem. That causes sclerification and dilatation of parenchyma, and multiple layers in some tissues.

Cellular and Metabolite Changes in the Secondary Phloem of Chinese Fir (Cuninghamia lanceolata (Lamb.) Hook.) during Dormancy Release

Wood in the cold temperate zone is the product of the alternation of the growing season and the dormant period of trees, but our knowledge of the process of dormancy release in trees remains limited. Chinese fir (Cuninghamia lanceolata (Lamb.) Hook.) was used to investigate cellular and metabolite changes in the secondary phloem tissue during dormancy release. The sampling dates were 2 March, 28 March, and 13 April. The microsections of wood-forming tissue were prepared using the paraffin embedding technique to observe the formation of cambium cells; metabolites in secondary phloem cells were extracted using a methanol/chloroform organic solvent system. The results showed that the secondary phloem consists of phloem fibers, sieve cells and phloem parenchyma. The cells were regularly arranged in continuous tangential bands and were in the order of Phloem fiber-Sieve cell-Phloem parenchyma-Sieve cell-Phloem parenchyma-Sieve cell-Phloem parenchyma-Sieve cell-Sieve cell-Phloem parenchyma-. The Chinese fir cambium was in dormancy on 2 March and 28 March, while on 13 April, it was already in the active stage and two layers of xylem cells with several layers of phloem cells were newly formed. The width of the cambium zone increased from 18.7 ± 5.7 μm to 76.5 ± 3.0 μm and the average radial diameter of sieve cells expanded from 15.4 ± 7.5 μm to 21.5 ± 7.4 μm after dormancy release. The cambium zone width and the average radial diameter of sieve cells before and after dormancy release were significantly different (p < 0.01). The phloem parenchyma cells without resin were squeezed and deformed by the sieve cells, and the width of the phloem during the active period was 197.0 ± 8.5 μm, which was larger than that during the dormant period. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based metabolomics was employed to analyze the secondary phloem of Chinese fir on 28 March and 13 April. Thirty-nine differential metabolites during dormancy release were detected. The results showed that the composition of Chinese fir metabolites was different before and after dormancy release. The relative increase in pyruvic acid and ascorbic acid contents proved that the rate of energy metabolism in Chinese fir increased substantially after dormancy release. Changes in cell development and the composition of metabolites revealed that the dormancy release of Chinese fir was at early April and the formation period of phloem tissue is earlier than xylem tissue.

Description of Intra-Annual Changes in Cambial Activity and Differentiation of Secondary Conductive Tissues of Aesculus hippocastanum Trees Affected by the Leaf Miner Cameraria ohridella

Aesculus hippocastanum trees are commonly infested by the leaf miner Cameraria ohridella, whose larval activity causes the destruction of the leaf parenchyma and induces defoliation. Pest attacks result in, e.g., production of smaller fruits and tree re-flowering in autumn. Concerning pest influence on stem structure only scarce information of narrower annual growth rings of wood has been published. Therefore, we determined the effect of the presence of the leaf miner infestation on intra-annual cambial activity and on differentiation of conductive tissues. These data were compared with phenological phases and pest activity. Pest feeding resulted in changes in onset, cessation and duration of cambial divisions, and differentiation of secondary xylem. The duration of cambial activity was about a month shorter in heavily infested trees and was connected with premature tree defoliation. Affected trees were characterised by a reduction in cambial divisions and earlier cessation of wood differentiation resulting in narrower wood rings. Furthermore, the infested trees exhibited altered wood structure, with more vessels of smaller diameters, however these changes did not affect its theoretical hydraulic conductivity. Interestingly, pest attack did not influence secondary phloem differentiation. The probable influence of long-term infestation on tree growth and condition was discussed.

Pharmacognostical evaluation and anti-convulsant property of Annona reticulata Linn. (Annonaceae) root

Background The present investigation was aimed at establishing the pharmacognostical parameters and preliminary phytochemical screening of Annona reticulata Linn. (Annonaceae) root. Pharmacognostical studies and phytochemical evaluation of A. reticulata root were carried out by following standard procedures to provide information that help to identify the species. The species of Annonaceae family are documented to possess anticonvulsant property, while A. reticulata and its root are reported to be used as a folklore medicine to treat epilepsy. In this study, anti-convulsant activity of the root extract was further investigated in mouse model with seizures induced by pentylenetetrazole (PTZ; 60 mg/kg, i.p.). Diazepam (5 mg/kg) was used as a standard anti-convulsant drug. Prior to induction of seizures, ethanol extract (100, 200, and 400 mg/kg, p.o.,) and 0.1% sodium CMC were administered. Later, the onset, duration of convulsions along with recovery was recorded. Results A. reticulata can be recognized by its crown shape, leaves with lengthy petioles, fleshy petals and heart-shaped fruits. Roots are cylindrical with rootlets and have aromatic odour. Presence of oil globules and rhomboidal calcium oxalate crystals in cortex, sclerenchyma cells in cortex and secondary phloem, starch grains in cortex, secondary phloem and secondary xylem, and uni- to tri-seriate medullary rays are the key diagnostic characters of root. Preliminary phytochemical screening of extracts revealed the presence of phenolic compounds, tannins, alkaloids, carbohydrates, flavonoids, glycosides, saponins, proteins, fixed oil and fats. The total alkaloid content in the root was 0.524% w/w, while total flavonoid and total phenolic content in ethanol extract were 16.65 mg QE/g and 59.54 mg GAE/g, respectively. Based on the values obtained from anti-convulsant activity, it is evident that the ethanol extract offered significant protection against PTZ-induced convulsion in mice. Conclusion The current pharmacognostical study aids not only in identification of crude drug material but also in establishing the standardization parameters. Further, the findings of this study indicated that the ethanolic extract of Annona reticulata Linn root displayed significant anti-convulsant property and this property could be attributed to imperative bioactives like flavonoids, phenolic compounds, alkaloids, in addition to other secondary metabolites.

Pharmacognostical and Phytochemical Evaluation of Aconitum heterophyllum Root

The present work aims to study the pharmacognostical and phytochemical characteristics of the roots of Aconitum heterophyllum. The study deals with the macroscopy, microscopy, powder analysis, physicochemical standardization, and preliminary phytochemical screening of Aconitum heterophyllum roots. Anatomical studies of the tuberous roots of Aconitum heterophyllum showed distinct endodermis, a wide zone of secondary phloem, and a ring of 4 to 9 vascular strands. The powder analysis revealed the presence of suberized cells of metaderm, reticulate xylem vessels, and starch grains. Physicochemical standardization such as moisture content, ash values, and extractive values of Aconitum heterophylluym was determined. For the identification of various chemical constituents, preliminary phytochemical screening was also studied.

Wood and bark anatomy of South African Picrodendraceae with systematic and ecological implications

Wood and bark structure of Androstachys johnsonii and Hyaenanche globosa (Picrodendraceae) is described. Two species share simple perforation plates, minute to small intervessel pits, and nonseptate fibres; these traits also reported in other Picrodendraceae. Androstachys is distinctive in having scanty paratracheal axial parenchyma and uniseriate rays with vessel-ray pits restricted to marginal cells. Bordered pits on fibre walls is an ancestral condition for the African Picrodendraceae. High vessel frequency and vessel grouping in Androstachys can be adaptive for semi-arid climate with wet summer. Both genera share the subepidermal phellogen initiation and the presence of thick-walled fibers and sclereids in secondary phloem. In Hyaenanche, the bark is dilated by stretching and divisions of parenchyma cells with formation of pseudocortex. Androstachys shows no ray dilatation, but sclerification of its parenchyma can make substantial contribution in bark expansion. Abundant trichomes on epidermis of young shoots of Androstachys are presumably involved in the water uptake from mists.

A Toxic Story: Phylogeny and Classification of Strychnos L. (Loganiaceae)

Strychnos is a pantropical genus of Loganiaceae (Gentianales), with approximately 200 species, that lacks a detailed worldwide phylogenetic understanding until now. We investigated the global phylogeny of the majority of Strychnos species, and evaluated morphologicaland key character patterns to discuss congruence between phylogenetic clades and sectional classification systems. We included 147 ITS sequences across 12 genera, with 127 samples (103 species) of Strychnos and 20 outgroup accessions (19 species) in a Bayesian analysis. Tribes Antonieae, Loganieae, and Spigelieae were supported as monophyletic, but Strychneae was resolved as polyphyletic due to the positioning of Gardneria placed outside of the Strychnos + Neuburgia clade. Strychnos was supported as strongly monophyletic with 12 strongly supported clades, but the relationships among many of these clades were not well resolved. Most of the 12 sections in the current infrageneric classification system of Strychnos were resolved as non-monophyletic, indicating the need for a revision of the sectional divisions. Characters common in species placed within the relatively more nested clades include a non-climbing habit, invasion of non-rainforest habitats, absence of tendrils,absence of secondary phloem, and elongated corolla tubes, suggesting that these characters are relatively derived conditions in the genus. Inflorescence position, fruit size, and fruit wall thickness are extremely variable and were distributed among various clades in our phylogeny. Stamen, pistil, seed and seed coat, and phytochemical characters have figured prominently in the taxonomy of the genus, but are as yet incompletely described, thus preventing significant inference about their evolution. Most of the 12 well-supported clades within Strychnos are restricted to specific continents, sometimes with limited dispersion between neighboring continents, suggesting a history of repeated cross-oceanic dispersal or vicariance patterns. The Neotropical clades nested within the African clades have the shortest branches and themost unresolved topologies, probably indicating relatively recent radiation in the Neotropics.

Morphoanatomy of three Indigofera species (Leguminosae-Papilionoideae) in Java, Indonesia

Fugarasti H, Muzzazinah, Ramli M. 2020. Morphoanatomy of three Indigofera species (Leguminosae-Papilionoideae) in Java Indonesia. Biodiversitas 21: 5531-5538. This study aimed to explore the morphological and detailed anatomical features of the stems, leaves, and roots from three Indonesian Indigofera species. Morphological-anatomical studies of three Indonesian Indigofera species were carried out using embedded microscopic preparations. The anatomical characters of the specimens were observed using a compound optical microscope with magnification 40x, 100x, and 400x. The observation showed the anatomical cross-section of I. tinctoria stem was rectangular, I. suffruticosa was hexagonal, and I. arrecta was rounded. The tissue structures of Indigofera species, from the outside layer, were the epidermis, thin cortex, secondary phloem (narrow or wide), thick secondary xylem, and conspicuous pith in the middle. Whilst, the corner of I. suffruticosa stem contained thick collenchyma. The vascular bundles were the open collateral. The leaves of Indigofera species are made up of the upper epidermis, mesophyll (palisade parenchyma, spongy parenchyma), and the lower epidermis. The vascular bundles were located in the middle, with five or six segments of the xylem elements and small groups of phloem elements, all in the parallel lines. The primary stele type of the roots is actinostele, cambium activity pushed him aside. The vascular bundle of the roots consisted of a dense and tight secondary xylem composed of thick-walled circular vessels (mostly tightly arranged). Data about the morphoanatomy structure of three Indonesian Indigofera species could complement the novelty of the morpho-anatomy information records obtained by previous researchers.