Per Cycle Research Articles

Long-read datasets of Kayu Bawang (Azadirachta excelsa (Jack) Jacobs) from 3 different identified seed stands in Bengkulu (Sumatra), Indonesia and its phylogenetic relationships

Abstract* Azadirachta excelsa (Jack) Jacobs, Kayu bawang (Meliaceae) is economically valuable and widely used by the local community in Bengkulu (Sumatra) as carpentry and construction wood because of its good durability class. However, it still has ambiguous scientific multiple names, such as Azadirachta excelsa, Protium javanicum, and Dysoxylum mollissimum. Additional tools such as molecular approaches can be used to verify whether it is true or not that Kayu bawang is scientifically named as Azadirachta excelsa based on previous morphological identification. This study aimed to construct draft chloroplast genome and verify the scientific name based on molecular identification using a single rbcL gene marker. Genomic DNA was extracted from bark cambium originated from three different provenances in Bengkulu, Indonesia, namely TBT-A, TBT-K, and TBT-S. MinION from Oxford Nanopore Technologies was used to sequence the samples following manufacture protocols SQK-LSK109 yielding 481.6 Mb for TBT-A, 597.4 Mb for TBT-K, and 853.1 Mb for TBT-S, respectively. Generated data were assembled and constructed, namely 58,780 bp (14 tRNAs and 47 encoding genes) for TBT-A, 142,139 bp (4 rRNAs, 24 tRNAs, and 78 encoding genes) for TBT-K, and 84,906 bp (24 tRNAs and 53 encoding genes) for TBT-S. Based on the phylogenetic tree, Azadirachta excelsa from three identified tree stands were placed in the same group with other Azadirachta excelsa accessions.

Friedelin: Structure, Biosynthesis, Extraction, and Its Potential Health Impact

Pharmaceutical companies are investigating more source matrices for natural bioactive chemicals. Friedelin (friedelan-3-one) is a pentacyclic triterpene isolated from various plant species from different families as well as mosses and lichen. The fundamental compounds of these friedelane triterpenoids are abundantly found in cork tissues and leaf materials of diverse plant genera such as Celastraceae, Asteraceae, Fabaceae, and Myrtaceae. They possess many pharmacological effects, including anti-inflammatory, antioxidant, anticancer, and antimicrobial activities. Friedelin also has an anti-insect effect and the ability to alter the soil microbial ecology, making it vital to agriculture. Ultrasound, microwave, supercritical fluid, ionic liquid, and acid hydrolysis extract friedelin with reduced environmental impact. Recently, the high demand for friedelin has led to the development of CRISPR/Cas9 technology and gene overexpression plasmids to produce friedelin using genetically engineered yeast. Friedelin with low cytotoxicity to normal cells can be the best phytochemical for the drug of choice. The review summarizes the structural interpretation, biosynthesis, physicochemical properties, quantification, and various forms of pharmacological significance.

Cork cellular and chemical features underlying bark environmental protection in the miombo species Parinari curatellifolia

Parinari curatellifolia is an important evergreen tree from the Miombo woodland of south-central and eastern Africa. The bark is corky, suggesting an increased protection against the ecosystem high temperatures and drought conditions as well as against wild fires. The cork in the bark rhytidome of P. curatellifolia was analyzed here for the first time with a focus on chemical and cellular features. P. curatellifolia cork has the cellular characteristics of cork tissues, with typical honeycomb structure in the tangential section and a brick-wall layer in the transverse and radial sections, without intercellular voids. Chemically P. curatellifolia cork has 8.4 % extractives, 33.9 % suberin, 31.9 % lignin and 25.2 % polysaccharides of the cork. The hemicelluloses are mostly xylans, with a substantial proportion of arabinose and galactose. Suberin showed a proportion of long chain lipids to glycerol (LCLip:Gly, mass ratio) of 8.5, and the long chain monomeric composition included a similar proportion of α,ω-diacids and ω-hydroxy acids (35.4 % and 31.5 % of long chain monomers) with a substantial proportion of monoacids (19.4 % of long chain monomers). Lignin is a guaiacyl-syringyl lignin with S/G of 0.32 and H:G:S of 1:14.1:4.5. The rhytidome composition and the cellular and chemical features of its cork are in line with environment-targeted protective features namely as a transpiration and insulation barrier, and as an increased fire protection.

Ethylene controls cambium stem cell activity via promoting local auxin biosynthesis.

The vascular cambium is the main secondary meristem in plants that produces secondary phloem (outside) and xylem (inside) on opposing sides of the cambium. The phytohormone ethylene has been implicated in vascular cambium activity, but the regulatory network underlying ethylene-mediated cambial activity remains to be elucidated. Here, we found that PETAL MOVEMENT-RELATED PROTEIN1 (RhPMP1), an ethylene-inducible HOMEODOMAIN-LEUCINE ZIPPER I transcription factor in woody plant rose (Rosa hybrida), regulates local auxin biosynthesis and auxin transport to maintain cambial activity. Knockdown of RhPMP1 resulted in smaller midveins and reduced auxin content, while RhPMP1 overexpression resulted in larger midveins and increased auxin levels compared with the wild-type plants. Furthermore, we revealed that Indole-3-pyruvate monooxygenase YUCCA 10 (RhYUC10) and Auxin transporter-like protein 2 (RhAUX2), encoding an auxin biosynthetic enzyme and an auxin influx carrier, respectively, are direct downstream targets of RhPMP1. In summary, our results suggest that ethylene promotes an auxin maximum in the cambium adjacent to the xylem to maintain cambial activity.

Development of the Vascular Cambium of Taxodium ascendens and Its Seasonal Activities in Subtropical China

The vascular cambium is an extensive and permanent secondary meristem with wood cells products of periclinal divisions commonly contributed to two directions and arranged in radial files of trees. Cambium activity is the origin of timber production. Taxodium ascendens Brongn is an exotic species in China, and its apical meristem and cambial activity are still elusive, resulting in a lack of understanding about its wood formation and improvement. We thus addressed this knowledge gap by studying Cambium activity. For studying, twigs from five 30-year-old healthy trees were collected between February-2017 and March-2018. Anatomy deciphered its apical meristem with a Cryptomeria–Abies type. The procambium appeared after leaf primordium and initially presented five lobes as observed transversely from a one-year-old shoot. The procambium under the apical differentiated into protophloem first and then protoxylem toward the inside. It means that protoxylem differentiated later than protophloem did. After dormancy, the vascular cambium began to be active, starting in early April 2017, which was later than shoot differentiation. On 25 July 2017, the cambial zone had 9–10 immature xylem cell layers. Both initiation and cessation of the xylem preceded that of the phloem. Until 10 October 2017, few immature elements were found, indicating the translation of cells from activity to dormancy. On 15 November 2017, the cambium contained 3–4 cells in radial rows, which demonstrated the dormancy of the cambium until next spring. Furthermore, immature xylem elements increased as cell layers in the cambium zone and cell fission increased. The growth pattern of T. ascendens revealed that cambial activity is highly seasonal and dependent on changes in abiotic conditions. Thus, the wood formation in the species will be significantly altered in a changing climatic pattern. These enhance our understanding of tree growth science, wood formation, wood structure, wood properties variation and wood improvement in tree breeding.

Исследование анатомического строения надземных органов катальпы прекрасной 1-го года вегетации

Woody-shrub vegetation has a key role in greening the urban environment. The excellent decorative qualities of the catalpa are important when choosing a woody plant for introduction in the conditions of the Karaganda region. Seedlings for a particular region must be grown locally to improve their adaptive properties. For a more complete study of the biological features of the species, an anatomical study of young catalpa plants was carried out. It was found that the leaf of the catalpa of the dorsal-ventral type, the stomata of the diacytic type, the cells of the epidermis with winding walls, trichomes and essential-oil glands are located on it; the petiole of the leaf is rounded in shape, with well-developed mechanical tissues around conductive bundles. On the internal structure of the stem and root, the beginning of the formation of cork tissue and the transition to a non-bundle type of structure of the conductive system is observed. In general, the structure of the catalpa is excellent evidence of the mesoxerophyte structure of the plant, which shows its demands on humidification conditions. Leaves are light type, that is, plants when planning green construction must be placed in areas with sufficient lighting. The results obtained will be supplemented by the study of anatomical indicators of plants of subsequent years of development

PECULIARITIES OF WILLOW (Salix alba) BARK MINERAL COMPOSITION

Willow bark is highly valuable in medicine, different branches of industry and ecology. In this respect antioxidants and minerals distribution between bark tissues seems to be highly valuable. Using ICP-MS mineral composition of willow bark cambium, phloem and periderm was determined for the first time. Predominance of P, K and Ca was recorded for cambium characterized by intensive metabolism. On the contrary, periderm demonstrated the highest concentrations of all heavy metals, except Ni, Al and As, and the highest coefficients of variation compared to phloem and cambium, especially for Al (107.5%), Pb (112.2%), V (133.3%), and Sn (90.9%). Though trace elements also prevail in periderm, low coefficient of variation between tissues indicates the importance of Fe, Mn, B, Zn, Cu and Mo in plants growth. Among tissues studied cambium recorded the highest antioxidant activity with relatively similar values of polyphenol content compared to periderm and phloem data. The results prove high prospects of willow bark cambium utilization as a valuable source of antioxidants and trace elements and of periderm as a natural adsorbent. KEYWORDS: willow bark, periderm, phloem, cambium, antioxidants, minerals.

Cork Development: What Lies Within.

The cork layer present in all dicotyledonous plant species with radial growth is the result of the phellogen activity, a secondary meristem that produces phellem (cork) to the outside and phelloderm inwards. These three different tissues form the periderm, an efficient protective tissue working as a barrier against external factors such as environmental aggressions and pathogen attacks. The protective function offered by cork cells is mainly due to the abundance of suberin in their cell walls. Chemically, suberin is a complex aliphatic network of long chain fatty acids and alcohols with glycerol together with aromatic units. In most woody species growing in temperate climates, the first periderm is replaced by a new functional periderm upon a few years after being formed. One exception to this bark development can be found in cork oak (Quercus suber) which display a single periderm that grows continuously. Quercus suber stands by its thick cork layer development with continuous seasonal growth. Cork raw material has been exploited by man for centuries, especially in Portugal and Spain. Nowadays, its applications have widened vastly, from the most known product, stoppers, to purses or insulating materials used in so many industries, such as construction and car production. Research on how cork develops, and the effect environmental factors on cork oak trees is extremely important to maintain production of good-quality cork, and, by maintaining cork oak stands wealthy, we are preserving a very important ecosystem both by its biodiversity and its vital social and economic role in areas already showing a population declination.

Floral symmetry: the geometry of plant reproduction.

The flower is an astonishing innovation that arose during plant evolution allowing flowering plants — also known as angiosperms — to dominate life on earth in a relatively short period of geological time. Flowers are formed from secondary meristems by co-ordinated differentiation of flower organs, such as sepals, petals, stamens, and carpels. The position, number and morphology of these flower organs impose a geometrical pattern — or symmetry type — within the flower which is a trait tightly connected to successful reproduction.During evolution, flower symmetry switched from the ancestral poly-symmetric (radial symmetry) to the mono-symmetric (bilateral symmetry) type multiple times, including numerous reversals, with these events linked to co-evolution with pollinators and reproductive strategies.In this review, we introduce the diversity of flower symmetry, trace its evolution in angiosperms, and highlight the conserved genetic basis underpinning symmetry control in flowers. Finally, we discuss the importance of building upon the concept of flower symmetry by looking at the mechanisms orchestrating symmetry within individual flower organs and summarise the current scenario on symmetry patterning of the female reproductive organ, the gynoecium, the ultimate flower structure presiding over fertilisation and seed production.

Potato Periderm Development and Tuber Skin Quality.

The periderm is a corky tissue that replaces the epidermis when the latter is damaged, and is critical for preventing pathogen invasion and water loss. The periderm is formed through the meristematic activity of phellogen cells (cork cambium). The potato skin (phellem cells) composes the outer layers of the tuber periderm and is a model for studying cork development. Early in tuber development and following tuber expansion, the phellogen becomes active and produces the skin. New skin layers are continuously added by division of the phellogen cells until tuber maturation. Some physiological disorders of the potato tuber are related to abnormal development of the skin, including skinning injuries and russeting of smooth-skinned potatoes. Thus, characterizing the potato periderm contributes to modeling cork development in plants and helps to resolve critical agricultural problems. Here, we summarize the data available on potato periderm formation, highlighting tissue characteristics rather than the suberization processes.

Epigenetics at the crossroads of secondary growth regulation.

The development of plant tissues and organs during post-embryonic growth occurs through the activity of both primary and secondary meristems. While primary meristems (root and shoot apical meristems) promote axial plant growth, secondary meristems (vascular and cork cambium or phellogen) promote radial thickening and plant axes strengthening. The vascular cambium forms the secondary xylem and phloem, whereas the cork cambium gives rise to the periderm that envelops stems and roots. Periderm takes on an increasingly important role in plant survival under climate change scenarios, but it is also a forest product with unique features, constituting the basis of a sustainable and profitable cork industry. There is established evidence that epigenetic mechanisms involving histone post-translational modifications, DNA methylation, and small RNAs play important roles in the activity of primary meristem cells, their maintenance, and differentiation of progeny cells. Here, we review the current knowledge on the epigenetic regulation of secondary meristems, particularly focusing on the phellogen activity. We also discuss the possible involvement of DNA methylation in the regulation of periderm contrasting phenotypes, given the potential impact of translating this knowledge into innovative breeding programs.

Phytochemical Investigation and Evaluation of Antimicrobial Activity of Aegle Marmelos Linn Thorns

Aegle marmelos, is a Traditional medicinal plant commonly known as ‘Bael’, with Ethnomedicinal application and has a great mythological significance for Hindus Traditional system of medicines like Ayurveda, Siddha and Unani have been highlighted the use of A. marmelos parts (bark, leaves, fruits, flowers etc.) for the treatments of various diseases. Present study aims at Phytochemical and biological evaluation of thorn extract of Aegle marmelos Linn. Standardization of powder is done by determination of ash value, extractive value and moisture content of Aegle marmleos. Pharmacognostic study was carried out in which macroscopic and microscopic characteristics were studied. For characterization plant parts used are Thorns of Aegle marmelos. The extraction was done by successive method in different solvents ranging from Non polar to polar solvents.The percentage yield of thorn is found to be in the range 0.4 %, 2.4933 %, 1.6 %, 0.2 %, 1.57 and 5.13% respectively. Phytochemical screening. conclude that the given plant material shows the presence of alkaloid, glycoside, flavonoids, tannin, phenolic, carbohydrates, proteins and amino acids. Transverse section of Aegle marmleos L. plant Thorn shows the presence of cork cambium, cortex, stone cells, starch grains, parenchymatous cells and Trichomes. The antimicrobial activity was checked using different test organisms.

The Analysis Effect of Selected Factors on the Shear Strength of Woodbark at Different Wood Species

The bark as a product of the dividing of wood and cork cambium consists of a set of protective layers of cells, which protect the living tissue (cambium) from the external environment and separate the bark from the wood. The structure of bark as a component of a living tree is completely different from wood. This article describes the testing of the adhesion of wood/bark in the longitudinal and tangential anatomical direction during the dormant and growing season on three choice wood species (oak, beech, and spruce). The results show a remarkable influence of the wood species and anatomical direction, as well as period of vegetation (dormant or growing season). All wood species had higher values of shear strength in the longitudinal direction compared to the tangential direction. The highest average values in the longitudinal direction were measured in the dormant period for sessile oak (0.49 MPa) and beech (0.48 MPa). The lowest value of shear strength in the longitudinal direction was measured for spruce (0.36 MPa). During the growing season, the highest average shear strength values were also measured in the longitudinal direction at beech (0.46 MPa) and oak (0.39 MPa). The lowest value of shear strength in the longitudinal direction was measured similarly for spruce (0.26 MPa).

A Cork Cell Wall Approach to Swelling and Boiling with ESEM Technology

The bark of cork oak (Quercus suber L.) is mostly used for cork stopper production; when bark undergoes a series of industrial procedures, boiling usually leads to changes in the characteristics of its tissue. Trees are traditionally grown under natural conditions; however, irrigation is now being used in plantations. This permanent water availability affects cork oak development, while its effects on industrial procedures are unknown. This study provides the first insight into the behaviour of the cell walls of cork during the process of swelling and boiling when trees have been grown under irrigation, that is, subject to a specific water regime. Cork tissue is analysed using environmental and scanning electron microscopy under three regimes: raw conditions, following immersion in water, and after boiling. Additionally, the radial expansion of samples is determined. The results show greater cell wall expansion in cork from the irrigated site than in cork from the traditional rainfed plot when hydrated for 24 h. After boiling, the cell walls of the cork from the rainfed site are thinner than in the raw stage, which is in contrast to the irrigated cork. This study suggests that irrigation during cork oak growth produces a higher capacity for adsorption, increasing cell wall thickness from the raw stage to the boiling stage.

Translational profile of developing phellem cells in Arabidopsis thaliana roots.

The phellem is a specialized boundary tissue providing the first line of defense against abiotic and biotic stresses in organs undergoing secondary growth. Phellem cells undergo several differentiation steps, which include cell wall suberization, cell expansion, and programmed cell death. Yet, the molecular players acting particularly in phellem cell differentiation remain poorly described, particularly in the widely used model plant Arabidopsis thaliana. Using specific marker lines we followed the onset and progression of phellem differentiation in A. thaliana roots and further targeted the translatome of newly developed phellem cells using translating ribosome affinity purification followed by mRNA sequencing (TRAP-SEQ). We showed that phellem suberization is initiated early after phellogen (cork cambium) division. The specific translational landscape was organized in three main domains related to energy production, synthesis and transport of cell wall components, and response to stimulus. Novel players in phellem differentiation related to suberin monomer transport and assembly as well as novel transcription regulators were identified. This strategy provided an unprecedented resolution of the translatome of developing phellem cells, giving a detailed and specific view on the molecular mechanisms acting on cell differentiation in periderm tissues of the model plant Arabidopsis.

The Making of Plant Armor: The Periderm.

The periderm acts as armor protecting the plant's inner tissues from biotic and abiotic stress. It forms during the radial thickening of plant organs such as stems and roots and replaces the function of primary protective tissues such as the epidermis and the endodermis. A wound periderm also forms to heal and protect injured tissues. The periderm comprises a meristematic tissue called the phellogen, or cork cambium, and its derivatives: the lignosuberized phellem and the phelloderm. Research on the periderm has mainly focused on the chemical composition of the phellem due to its relevance as a raw material for industrial processes. Today, there is increasing interest in the regulatory network underlying periderm development as a novel breeding trait to improve plant resilience and to sequester CO2. Here, we discuss our current understanding of periderm formation, focusing on aspects of periderm evolution, mechanisms of periderm ontogenesis, regulatory networks underlying phellogen initiation and cork differentiation, and future challenges of periderm research.

Study of the strength limit of the bark of a plum tree trunk under the action of normal compression

Purpose. Reduction of damage to trunks of tree bark due to substantiation of the parameters of the harvesting technique using the method of determining the strength limit of tree bark in field conditions during research and the device for its implementation. Methods. Standardized and improved methods of determining the strength limit of tree bark under normal load were used, as well as the basic provisions for conducting laboratory and field experiments. Results. During field research, the developed method of determining the strength limit of tree bark was applied. It was established that highly elastic deformation of the bark does not affect the functional properties of phloem, phelloderm and cambium, i.e. after removing the load, the bark is completely restored, and irreversible plastic deformation leads to the death of bark fibers. The transition to the region of plastic deformation is marked by a sharp increase in the rate of deformation at a constant rate of load application, i.e. the strength limit of the crust is overcome and the flow fluidity phase. To implement the improved method, the developed device was used to determine the strength limit of the crust under normal compression, which made it possible to substantiate the parameters of the overlays of working organs and modes of operation of shakers of fruit-harvesting means and machines during development. Conclusions. The proposed method and device made it possible to determine the bark strength limit during normal compression in the field without damaging the tree bark. It was established that for plum orchard trees with diameters of 50–200 mm, it is 0.68–1.74 MPa and depends on the thickness of the cork tissue, which increases with the age of the tree. The method of implementing the method and the device is universal, therefore it is advisable to use it during field tests to determine the limit of bark strength for other fruit and nut trees. Keywords: method, instrument, tree bark, normal pressure, strength limit.

Spatiotemporal development of suberized barriers in cork oak taproots.

The longevity and high activity of the cork cambium (or phellogen) from Quercus suber L. (cork oak) are the cornerstones for the sustainable exploitation of a unique raw material. Cork oak is a symbolic model to study cork development and cell wall suberization, yet most genetic and molecular studies on these topics have targeted other model plants. In this study, we explored the potential of taproots as a model system to study phellem development and suberization in cork oak, thereby avoiding the time constraints imposed when studying whole plants. In roots, suberin deposition is found in mature endodermis cells during primary development and in phellem cells during secondary development. By investigating the spatiotemporal characteristics of both endodermis and phellem suberization in young seedling taproots, we demonstrated that secondary growth and phellogen activity are initiated very early in cork oak taproots (approx. 8days after sowing). We further compared the transcriptomic profile of root segments undergoing primary (PD) and secondary development (SD) and identified multiple candidate genes with predicted roles in cell wall modifications, mainly lignification and suberization, in addition to several regulatory genes, particularly transcription factor- and hormone-related genes. Our results indicate that the molecular regulation of suberization and secondary development in cork oak roots is relatively conserved with other species. The provided morphological characterization creates new opportunities to allow a faster assessment of phellogen activity (as compared with studies using stem tissues) and to tackle fundamental questions regarding its regulation.

Use of factors of photoperiod duration and growth regulators to increase the yield of mixoploid plants in C0 generation in meadow clover (Trifolium pratense L.)

It has been established that the studied mode of cultivation of meadow clover under controlled environmental conditions, with continuous illumination with an intensity of 18-20 thousand lux and a constant temperature of + 25 °C, causes significant morphological changes in meadow clover. Compared with the optimal (control), the proposed growing regime halves the development time of plants and by the same amount reduces the severity of morphological traits, while simultaneously causing apical dominance in 54% of plants. Spraying plants with phytohormone in the form of naphthylacetic acid in all studied concentrations reduced the growing season by 4-8 days and increased pollen fertility by 8-10%. The optimal concentration of naphthylacetic acid (NLA) was revealed to suppress the growth of secondary meristems in meadow clover under the conditions of an experimental plant growing regime. The most significant effect on the manifestation of apical dominance was shown by the use of naphthylacetic acid at a concentration of 0.001%. The combined use of the proposed growing regime and treatment with naphthylacetic acid at a concentration of 0.001% increased the yield of plants with apical dominance from 54.5% to 76%. The developed method has shown high efficiency for the creation of tetraploid forms of meadow clover. When growing clover C0 generation and selection of mixoploid plants, the yield of mixoploids increased 5.4 times, the survival rate of seedlings increased by 21%, the time to obtain one generation and the selection of mixoploids decreased by 58%.

Cork influenced by a specific water regime—macro and microstructure characterization: the first approach

Cork is the most valuable non-wood product of the cork oak (Quercus suber L.). However, the cork oak sector may be at risk due to climatic and economic pressures on cork oak forests, affecting both the quantity and technological quality of products. At some sites, irrigation may present a solution for stimulating cork growth and thereby increasing production. This study presents an initial approach to characterizing cork grown in a forest stand associated with a specific water regime, by comparing cork growth on two plots—irrigated and a traditional rainfed—over an initial five-year period. Samples of cork tissue were analysed and several parameters were set: cell area, diameter, cell-wall thickness, number of cells, porosity, growth, and density. Irrigation plot samples showed on average: 25.83 ± 3.74 mm thickness, 5.17 ± 1.49 mm cork-ring width, 0.149 ± 0.041 g.cm−3 density, 13 ± 3.4% porosity coefficient in the tangential plane, 407.58 ± 268.22 µm2 cell area in the tangential plane and 887.80 ± 449.14 µm2 in the transverse plane, a total number of cells of 1232 ± 147 per mm2, and 1.03 ± 0.30 µm cell-wall thickness; whereas traditional rainfed plot samples presented: 21.33 ± 5.48 mm thickness, 3.08 ± 1.44 mm cork-ring width, 0.167 ± 0.068 g.cm−3 density, 10 ± 3.5% porosity coefficient in the tangential plane, 304.31 ± 205.83 µm2 cell area in the tangential plane and 752.45 ± 398.94 µm2 in the transverse plane, a total number of cells of 1481 ± 153 per mm2, and 1.204 ± 0.327 µm cell-wall thickness. As regards irrigation, two parameters, ring width and porosity coefficient, proved to be statistically significant, in contrast to density.