Xylem Vessels Research Articles

Evaluating wettability of vessels in poplar by Micro-CT imaging

Abstract The wettability of wood affects some natural phenomena and applications in industry, such as the ascent of sap in the plant stem, wood drying, and impregnation processes for wood modification. Wettability is generally evaluated by measuring the contact angle using techniques such as the sessile drop method and the Wilhelmy method. However, these methods are not applicable to phenomena at the micro-scale such as liquid transport in hardwood vessels. In this study, micro-CT was used to measure the contact angle of liquid in a single wood vessel directly at the submicron scale. The wettability of a wood vessel was analyzed using contact angles of distilled water and diiodomethane. Conventional contact angles of the wood surface were measured using a fixed drop technique. The average contact angle in a vessel determined by the direct CT observation was significantly smaller than that on the wood surface measured by the sessile drop technique. This discrepancy is attributable to the higher total surface energy of the vessel compared to the free energy of a flat surface. The difference in surface energy is due to different chemical composition distributions in various cell wall layers, roughness and surface topography between the wood surface and vessels, and moisture state.

E. Globulus Vessel and Fibre Chemical Analysis

Hardwood species have a complex cellular structure consisting of fibres, vessel elements and parenchyma cells with different chemical compositions. However, the presence of vessels with significant dimensions in their structure is a recurrent problem in the operation of industrial UWF paper printing. Since the 1980s, vessel picking and ink refusal are problems that paper professionals have tried to solve, but solutions for these have not yet been fully found. If vessels are concentrated in a stream, they can be pre-treated (e.g., by mechanical refining) and reincorporated into the pulp. Other strategies aim at vessel enzymatic and/or chemical passivation and sheet surface chemical treatment, altering the vessel adhesion to the fibre network. This requires vessel concentration at laboratorial level for proper chemical studies, such as FE-SEM, μ-XPS, TOF-SIMS and μFTIR. The main objective of our experimental study was to examine bleached kraft pulp E. globulus vessel and fibre composition. For this we performed EDX and μ-FTIR analysis on both fibre and vessel elements, and obtained the carbohydrate composition, the total acids content, the hexenuronic acids content and the zeta potential.
 Keywords: E. globulus, vessel, EDX, μ-FTIR, sugar content, zeta potential

Trading water for carbon in the future: Effects of elevated CO2 and warming on leaf hydraulic traits in a semiarid grassland.

The effects of climate change on plants and ecosystems are mediated by plant hydraulic traits, including interspecific and intraspecific variability of trait phenotypes. Yet, integrative and realistic studies of hydraulic traits and climate change are rare. In a semiarid grassland, we assessed the response of several plant hydraulic traits to elevated CO2 (+200 ppm) and warming (+1.5 to 3°C; day to night). For leaves of five dominant species (three graminoids and two forbs), and in replicated plots exposed to 7 years of elevated CO2, warming, or ambient climate, we measured: stomatal density and size, xylem vessel size, turgor loss point, and water potential (pre‐dawn). Interspecific differences in hydraulic traits were larger than intraspecific shifts induced by elevated CO2 and/or warming. Effects of elevated CO2 were greater than effects of warming, and interactions between treatments were weak or not detected. The forbs showed little phenotypic plasticity. The graminoids had leaf water potentials and turgor loss points that were 10% to 50% less negative under elevated CO2; thus, climate change might cause these species to adjust their drought resistance strategy away from tolerance and toward avoidance. The C4 grass also reduced allocation of leaf area to stomata under elevated CO2, which helps explain observations of higher soil moisture. The shifts in hydraulic traits under elevated CO2 were not, however, simply due to higher soil moisture. Integration of our results with others' indicates that common species in this grassland are more likely to adjust stomatal aperture in response to near‐term climate change, rather than anatomical traits; this contrasts with apparent effects of changing CO2 on plant anatomy over evolutionary time. Future studies should assess how plant responses to drought may be constrained by the apparent shift from tolerance (via low turgor loss point) to avoidance (via stomatal regulation and/or access to deeper soil moisture).

In-situ copper ion reduction and micro encapsulation of wood-based composite PCM with effective anisotropic thermal conductivity and energy storage

This work develops metallic wood-based phase change materials (MWPCM) with high-performance anisotropic thermal conductivity by impregnating wood with phase change microcapsules and subsequent in situ chemical deposition of copper inside the wood cell lumen. Phase change material (PCM) is encapsulated by polymer to form phase change microcapsules, which solve the leakage problem effectively. Benefited with the well-aligned and hierarchical porous structure of wood, phase change microcapsules coated with copper layer are orderly confined inside wood vessels and fibers, developing a continuous and anisotropic heat transfer network along the highly oriented transport tissues of wood. The morphology, chemical structure and crystallization of microcapsules and MWPCM are investigated using scanning electronic microscope (SEM), flourier transformation infrared spectroscopy (FTIR) and X-ray diffractometer (XRD), and the thermal storage capacity, thermal stability and thermal conductivity of the developed PCM composites are examined using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and laser flash diffusivity apparatus (LFA) respectively. The results show that PCM capsules were effectively accommodated in orderly porous wood as a carrier; the radial and longitudinal thermal conductivity of MWPCM reached 0.37 W/(m*K) and 0.53 W/(m*K), which increased by 362% and 211% compared to pure wood, respectively. The anisotropic thermal conductivity of MWPCM enabled an efficient heat transfer along the longitudinal direction and reduced the heat loss in the transverse direction. MWPCM exhibited good thermal energy storage capacity (92.9 J/g and 94.6 J/g) and suitable phase change temperature (11.4 °C and 29.4 °C) for indoor thermal energy management. MWPCM also displayed outstanding shape-stability, excellent thermal stability and temperature regulation, which has a great potential for building energy collecting, storage and management.

Improving the Quality and Production of Philodendron Plants Using Nanoparticles and Humic Acid

A pot experiment was conducted during the 2019/2020 and 2020/2021 seasons to evaluate the effect of silver nanoparticles (SNPs), iron nanoparticles (FeNPs), zinc nanoparticles (ZnNPs), and nitrogen, phosphorus, and potassium nanoparticles (NPK NPs) and humic acid (HA) in improving the growth of Philodendron plants. Our findings indicated that the highest increase in plant height and leaf width was recorded with 60 mg/L SNPs. Additionally, the highest values in the number of leaves/plant were recorded with 60 mg/L SNPs compared to the control. FeNPs at 150 mg/L treatment gave the best result of total chlorophyll and carotenoid content, followed by SNPs at 60 mg/L and then NPK NPs at 2 mL/L in the two seasons. Furthermore, ZnNPs at 200 mg/L, SNPs at 20 mg/L, SNPs at 40 mg/L, and SNPs at 60 mg/L gave the best results of enzyme activity (catalase, peroxidase, and polyphenol oxidase). However, the treatments with 40 and 60 mg/L SNPs led to improve the anatomical characters of leaves and stem such as thickness of the blade, mesophyll tissue, xylem vessel diameter, vascular bundle dimension, stem diameter, and epidermis cell dimension compared with other treatments and the control.

Improved maceration techniques to study the fruit vascular anatomy of grape

The visualization and evaluation of fruit vascular bundles in grape are indispensable for understanding the development and growth of the fruit. The vascular bundles in grape are as thin as human hair, and strongly adhere to flesh cells, making it difficult to isolate individual intact vessel elements. Currently there is little information about methods to characterize grape vascular tissue. In this study, we describe an easy and effective technique to visualize the xylem cell structure of the ‘Red Globe’ grape (Vitis L.). The intact vascular bundles of the grape were isolated through enzymatic degradation of flesh cells by hydrolases which were effective in removing flesh cells from vascular bundles. This enabled the illustration of the fine surface structure of vessel elements and their arrangement in the vascular bundles of the grape. This modified method to separate the vascular bundles into individual vessel elements was more effective than former methods of manually shaking to isolate individual vessels. Clear images of xylem vessel arrangement and structural characteristics of individual vessel element were acquired by light microscopy (BX51, Olympus, Tokyo, Japan), transmission electron microscopy (Tecnai 12, Philips, Netherlands) and scanning electron microscopy (GeminiSEM 300, Carl Zeiss, Germany). In addition, the 3D structure of vessel elements was observed using confocal laser scanning microscopy (Zeiss: model: LSM-880, Oberkochen, Germany). The imaging techniques for visualizing and analyzing the structure of xylem vessels in grape described in this study are an improvement of past methods. An effective method to isolate grape vascular bundles from flesh cells was also developed, which enables the imaging of the fine surface structure of vessel elements and their arrangement in grape vascular bundles. By adjusting the process of maceration of vascular bundles, an easy and effective method was developed to gently disrupt the plant tissue and isolate individual vessel elements. These improved techniques are suitable to observe the intact morphology of vascular bundles in the grape, improve experimental efficiency and accelerate new discoveries on the anatomical structure of the grape.

Pharmacognostic Characterization for Taxonomic Identification of Bacopa monnieri (L.) Wettst. for Quality Control

Pharmacognostic studies played a crucial role in checking the possibilities and threat of adulteration among natural drugs by macroscopic and microscopic examination of plant materials. Organoleptic characters, macroscopic and microscopic studies, physicochemical and fluorescence analysis of Bacopa monnieri (L.)Wettst. has been carried out to determine the anatomical and pharmacognostic portrayal. The organoleptic studies revealed that B. monnieri is green in colour, bears a characteristic smell, leaves have smooth soft texture and bitter in taste. Stomata of anomocytic type and stomatal index was 17.77 and 18.18 in upper and lower epidermis respectively. Glandular trichome was present on the leaf surface and petiole. Study of powder microscopic analysis and fluorescence characteristics reveals round and oval starch granules, sclerenchymatous cells, lignified fibres, vascular bundles, spherical oil globules, raphides, druses, thin fibres and compounds oil droplets, xylem vessels with spiral and reticulates thickenings in the powder of different part of the plant. Observations revealed that the study has a great potential in unraveling the identification keys of plants species by highlighting various pharmacognostic aids.

Physiological and Structural Responses to Prolonged Water Deficit in Young Trees of Two Olive Cultivars.

This study aimed to characterize the physiological and structural responses of potted one-year-old olive trees belonging to two olive cultivars—‘Nocellara del Belice’ and ‘Cerasuola’—exposed to prolonged drought under greenhouse conditions. Two irrigation treatments based on evapotranspiration (ET) were imposed for 69 days, i.e., well-watered (WW, 100% ET) and drought-stressed (DS, 10–30% ET). Leaf stomatal conductance (gs), stem water potential (Ψstem), transpiration (E), photosynthetic capacity (Amax), water use efficiency (WUE), stem (Kstem) and root (Kroot) hydraulic conductance, trunk diameter variations (TDV), and leaf patch attenuated pressure fluctuations (pp, a proxy of the inverse of leaf turgor pressure) were measured in WW and DS trees at different stages of the experiment. Leaf gs did not significantly differ between cultivars under DS, whereas differences in Ψstem only became significant at the end of prolonged drought, when ‘Nocellara del Belice’ experienced Ψstem < −4 MPa. ‘Cerasuola’ trees expressed the best WUE under drought, although they were more susceptible to photoinhibition under optimal plant water status. Both cultivars tended to increase their Kstem at the end of the drought period. A marked reduction in Kroot occurred in ‘Cerasuola’ plants after prolonged drought; however, a similar mechanism was not observed in ‘Nocellara del Belice’. The ratio between Kstem and Kroot exponentially increased towards the end of the prolonged drought period in both cultivars, but more markedly in ‘Cerasuola’. TDV and pp trends suggested that ‘Cerasuola’ plants keep better plant water status under severe drought compared to ‘Nocellara del Belice’ by maintaining high leaf turgor and reduced trunk diameter fluctuations. These responses may be related to reduced cell wall elasticity and xylem vessel size and/or wall thickness—drought avoidance mechanisms. The Kstem/Kroot ratio can serve as an indicator of drought stress avoidance mechanisms to compare genotype-specific responses to drought stress.

VND-INTERACTING2 effectively inhibits transcriptional activities of VASCULAR-RELATED NAC-DOMAIN7 through a conserved sequence.

An Arabidopsis NAC domain transcription factor VND-INTERACTING2 (VNI2) was originally isolated as an interacting protein with another NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), a master regulator of xylem vessel element differentiation. VNI2 inhibits transcriptional activation activity of VND7 by forming a protein complex. Here, to obtain insights into how VNI2 regulates VND7, we tried to identify the amino acid region of VNI2 required for inhibition of VND7. VNI2 has an amino acid sequence similar to the ETHYLENE-RESPONSIVE ELEMENT BINDING FACTOR (ERF)-associated amphiphilic repression (EAR) motif, conserved in transcriptional repressors, at the C-terminus. A transient expression assay showed that the EAR-like motif of VNI2 was not required for inhibition of VND7. The C-terminal deletion series of VNI2 revealed that 10 amino acid residues, highly conserved in the VNI2 orthologs contributed to effective repression of the transcriptional activation activity of VND7. Observation of transgenic plants ectopically expressing VNI2 showed that the identified 10 amino acid sequence strongly affected xylem vessel formation and plant growth. These data indicated that the 10 amino acid sequence of VNI2 has an important role in its transcriptional repression activity and negative regulation of xylem vessel formation.

Numerical Simulation of the Deformation Behavior of Softwood Tracheids for the Calculation of the Mechanical Properties of Wood-Polymer Composites.

From a fiber composite point of view, an elongated softwood particle is a composite consisting of several thousand tracheids, which can be described as fiber wound hollow profiles. By knowing their deformation behavior, the deformation behavior of the wood particle can be described. Therefore, a numerical approach for RVE- and FEM-based modelling of the radial and tangential compression behavior of pine wood tracheids under room climate environment is presented and validated with optical and laser-optical image analysis as well as tensile and compression tests on pine sapwood veneer strips. According to the findings, at 23 °C and 12% moisture content, at least 10 MPa must be applied for maximum compaction of the earlywood tracheids. The latewood tracheids can withstand at least 100 MPa compression pressure and would deform elastically at this load by about 20%. The developed model can be adapted for other wood species and climatic conditions by adjusting the mechanical properties of the base materials of the cell wall single layers (cellulose, hemicellulose, lignin), the dimensions and the structure of the vessel elements, respectively.

Phenotyping and modeling of root hydraulic architecture reveal critical determinants of axial water transport.

Water uptake by roots is a key adaptation of plants to aerial life. Water uptake depends on root system architecture (RSA) and tissue hydraulic properties that, together, shape the root hydraulic architecture. This work investigates how the interplay between conductivities along radial (e.g. aquaporins) and axial (e.g. xylem vessels) pathways determines the water transport properties of highly branched RSAs as found in adult Arabidopsis (Arabidopsis thaliana) plants. A hydraulic model named HydroRoot was developed, based on multi-scale tree graph representations of RSAs. Root water flow was measured by the pressure chamber technique after successive cuts of a same root system from the tip toward the base. HydroRoot model inversion in corresponding RSAs allowed us to concomitantly determine radial and axial conductivities, providing evidence that the latter is often overestimated by classical evaluation based on the Hagen–Poiseuille law. Organizing principles of Arabidopsis primary and lateral root growth and branching were determined and used to apply the HydroRoot model to an extended set of simulated RSAs. Sensitivity analyses revealed that water transport can be co-limited by radial and axial conductances throughout the whole RSA. The number of roots that can be sectioned (intercepted) at a given distance from the base was defined as an accessible and informative indicator of RSA. The overall set of experimental and theoretical procedures was applied to plants mutated in ESKIMO1 and previously shown to have xylem collapse. This approach will be instrumental to dissect the root water transport phenotype of plants with intricate alterations in root growth or transport functions.

Morphology, biochemistry, and yield of cassava as functions of growth stage and water regime

Water deficit affects morphological attributes and physiological and biochemical processes important to plants. Although cassava crop is known for its rusticity and adaptability to adverse environmental conditions, there have not been any studies reporting the effects of water deficit at different growth stages on cassava morphology and biochemistry. The objective of this research was to evaluate the morphological, anatomical, biochemical, and yield responses of cassava under different water regimes in three growth stages. The experimental design used was completely randomized 3 × 3 factorial scheme consisting of three growth stages (GS) [90–180 (GS3), 180–270 (GS4), and 270–360 days after planting (DAP) (GS5)] and three soil water tensions (-10, -40, and -70 kPa) with five replicates. Plants were affected, mainly in GS3, by -40 and -70 kPa soil tensions, with decreases in stem diameter, plant height and number of leaves. Leaf anatomy was also affected by water deficit in GS3, with reductions in the mesophyll thickness (13.7%), spongy parenchyma (19.9%), epidermal cells on the blade abaxial surface (18.0%) and in the number of xylem vessels (15.8%); in addition, there was an increase in the wall thickness (105.0%) and in the diameter (85.5%) of the xylem vessels. Under prolonged water deficit, there was an increase in the activity of superoxide dismutase and catalase, which were efficient in controlling H2O2. The imposition of water deficit drastically reduced the yield of commercial and tuberous roots in GS3 (82.1% and 65.0%) and GS5 (45.7% and 32.5%). Our study shows that the period of crop susceptibility to water deficit is longer than previously thought, evidencing the need for greater attention to water availability between 90 and 180 and between 270 and 360 DAP, as it may aid in reducing the negative effects of water deficit on the biochemistry, anatomy, and yield components of cassava.

Differential Effects of Potassium Chloride on Vascular Tissues, Morphological Traits and Germination of Tomato with Sperm Swarm-based Nutrient Optimization

Potassium chloride (KCl)-induced stress has been predominantly tested on higher crops such as cotton, rice, and wheat. What open agriculture needs now is the extended understanding of possible contributions and detrimental effects of KCl dynamics to tomato as this is one of the major crops consumed worldwide. In this study, the impacts of KCl on the three Philippine tomato (Solanum lycopersicum) genotypes namely, Perlas, Diamante Max F1, and Mica, in separate mesocosms were visualized and measured based on morphological, vascular tissues, and germination variability responses. Three KCl treatments were deployed, which are control (Tc, 0.05 mM), deficit (Td, 0.025 mM), and excess (Te, 0.5 mM), in 3 replicates. KCl-deficit treatment showed improvement in germination rate and vigor index and deteriorated Timson germination index for tomato seedlings. Excess KCl treatment distinctively promotes a higher root (R) to shoot (S) length ratio for Perlas variant with rusty red-orange root color. R/S length increases from control, deficit to excess KCl and R/S fresh and dry weights quadratically increase from control, excess to deficit KCl. The inconsistency of Td and Te treatments to provide equally productive outcomes across the 3 genotypes on the first 37 days after sowing led to the use of 3 bio-inspired algorithms namely, moth-flame, sperm-swarm, and jellyfish swarm optimizers, in determining the most suitable KCl concentration for growth promotion. Multigene symbolic genetic programming was used in constructing the fitness models of five phytomorphological phenotypes namely, root and shoot lengths and weights and leaf count, as functions of KCl concentration and cultivation period. Light microscopy showed that sperm swarm-optimized KCl (0.038 μM) widens the diameter of xylem and phloem vessels in the vegetative stage which is important as they are responsible for transporting nutrients, water, and photosynthesis by-products. Hence, KCl is an essential micronutrient that could alter the growth of crops. HIGHLIGHTS KCl-deficit treatment showed improvement in germination rate and vigor index and deteriorated Timson germination index for tomato seedlings Excess KCl treatment distinctively promotes a higher root to shoot length ratio for Perlas variant with rusty orange root color Multigene symbolic genetic programming generated the fitness models of phytomorphological phenotypes as functions of KCl concentration and cultivation period Sperm swarm-optimized KCl (0.038 μM) widens the diameter of xylem and phloem vessels in the vegetative stage (up to DAS 37) R/S length increases from control, deficit to excess KCl; R/S fresh and dry weights quadratically increase from control, excess to deficit KCl GRAPHICAL ABSTRACT

Influence of Juvenile Growth on Xylem Safety and Efficiency in Three Temperate Tree Species

The evolution of the internal water transport system was a prerequisite for high plant productivity. In times of climate change, understanding the dependency of juvenile growth on xylem hydraulic physiology is therefore of high importance. Here, we explored various wood anatomical, hydraulic, and leaf morphological traits related to hydraulic safety and efficiency in three temperate broadleaved tree species (Acer pseudoplatanus, Betula pendula, and Sorbus aucuparia). We took advantage of a severe natural heat wave that resulted in different climatic growing conditions for even-aged plants from the same seed source growing inside a greenhouse and outside. Inside the greenhouse, the daily maximum vapour pressure deficit was on average 36% higher than outside during the growing seasons. Because of the higher atmospheric moisture stress, the biomass production differed up to 5.6-fold between both groups. Except for one species, a high productivity was associated with a high hydraulic efficiency caused by large xylem vessels and a large, supported leaf area. Although no safety-efficiency trade-off was observed, productivity was significantly related to P50 in two of the tree species but without revealing any clear pattern. A considerable plasticity in given traits was observed between both groups, with safety-related traits being more static while efficiency-related traits revealed a higher intra-specific plasticity. This was associated with other wood anatomical and leaf morphological adjustments. We confirm that a high hydraulic efficiency seems to be a prerequisite for a high biomass production, while our controversial results on the growth–xylem safety relationship confirm that safety-efficiency traits are decoupled and that their relationship with juvenile growth and water regime is species-specific.

MiR395c Regulates Secondary Xylem Development Through Sulfate Metabolism in Poplar.

Secondary xylem development requires the coordination of multiple regulatory factors, including plant hormones, transcription factors, and microRNAs (miRNAs). MiR395 is an important regulator involved in sulfate metabolism, but its function in plant development is unclear. This study investigated the functions of miR395c in the secondary xylem development in Populus alba × P. glandulosa. MiR395c was highly expressed in the shoot apex and secondary xylem. The overexpression of miR395c resulted in an increase in both secondary xylem width and vessel dimension, as well as a decrease in the thickness of the secondary cell wall of the xylem fiber. Further analysis showed that miR395c inhibited biosynthesis of sulfate metabolic products by targeting ATPS genes, which led to the reduction of Abscisic acid (ABA) synthesis and down-regulation of MYB46 expression. Our results indicate that miR395c regulates the secondary xylem development process via sulfate metabolism in Populus.

Particle-Based Imaging Tools Revealing Water Flows in Maize Nodal Vascular Plexus

In plants, water flows are the major driving force behind growth and play a crucial role in the life cycle. To study hydrodynamics, methods based on tracking small particles inside water flows attend a special place. Thanks to these tools, it is possible to obtain information about the dynamics of the spatial distribution of the flux characteristics. In this paper, using contrast-enhanced magnetic resonance imaging (MRI), we show that gadolinium chelate, used as an MRI contrast agent, marks the structural characteristics of the xylem bundles of maize stem nodes and internodes. Supplementing MRI data, the high-precision visualization of xylem vessels by laser scanning microscopy was used to reveal the structural and dimensional characteristics of the stem vascular system. In addition, we propose the concept of using prototype “Y-type xylem vascular connection” as a model of the elementary connection of vessels within the vascular system. A Reynolds number could match the microchannel model with the real xylem vessels.

Cinnamic Acid Toxicity on the Structural Resistance and Photosynthetic Physiology of Faba Bean Promoted the Occurrence of Fusarium Wilt of Faba Bean, Which Was Alleviated Through Wheat and Faba Bean Intercropping.

BackgroundThe pattern of intercropping wheat and faba bean is an effective means to alleviate continuous cropping obstacles.AimTo study the mechanism by which cinnamic acid promotes faba bean wilt and the mechanism by which intercropping alleviates this effect.MethodsHydroponics was used to study the effects of inoculation with or without Fusarium oxysporum f. sp. fabae (FOF) and the effect of addition of different concentrations of cinnamic acid on seedling growth, Fusarium wilt, stem cell wall degrading enzyme activity, lignin content, tissue structure of the stem and leaf photosynthesis in monocropping and intercropping systems following the inoculation of faba bean with FOF.ResultsTreatment with FOF significantly reduced the biomass and leaf photosynthesis of faba bean compared with the control. Microscopic observation showed that the xylem vessels of the stem were slightly thickened. Compared with FOF alone, the combination of FOF and cinnamic acid stress significantly increased the activity of cell wall degrading enzymes (CWDEs) produced by FOF in the stem and content of lignin in the stem. Microstructural observation showed that cell wall thickening of the xylem conduit, stratification, formation of a cavity and even caused the dispersion of tissue cell structure in the stem tissue of faba bean. Furthermore, the biomass and leaf photosynthesis of faba bean decreased significantly, and the occurrence of faba bean wilt increased. Compared with the faba bean monocropping treatment, the wheat and faba bean intercropping treatment significantly reduced the activity of CWDEs of FOF produced in faba bean stems and increased the lignin content. In addition, observation of the microstructure indicated that the tissue structural cell wall thickened after the stem had decreased, and the amount of colloidal substances and their containment decreased, causing a further decrease in tissue deformation, smaller intercellular spaces, less divided layer cell damage, an increase in the aboveground biomass and leaf photosynthesis of faba bean and a decrease in the occurrence of faba bean wilt.ConclusionCinnamic acid decreased the resistance of tissue structure and promoted the occurrence of wilt. Wheat and faba bean intercropping improved the resistance of tissue structure, which reduced the occurrence of wilt.

Pharmacognostic standardization of Rhododendron afghanicum through scanning electron microscopy and analytical techniques.

The aim of this study was to assess and compare the pharmacognostic and microscopic features of the selected parts of Rhododendron afghanicum Aitch. & Hemsl. It is a perennial and shrub. Anatomy of stem and leaves depicted dicot structure. It will provide knowledge about standardization, authentication, and adulteration with its co-species. The macroscopic examination reveals that fresh leaves are green, pleasant odor with a bitter taste. The leaf is oblong-elliptic in shape and sub-acute at apex; rounded at the base with entire margin. Stem is irregular and the outer surface is light brown, rough with fissures and ridges. Microscopic examination indicated the presence of xylem, phloem, peltate trichome, epidermal cells, collenchymas cells, paracytic stomata, and reticulate vessels. Stem microscopy reveals epidermis, hypodermis, cortex, sclerenchymatous sheath, phloem, xylem, and pith. It will be helpful in identification and quality control. Micro-morphological features were observed through SEM. EDX spectroscopy were carried out and revealed the presence of calcium, silicon, and potassium. Phytochemical analysis revealed the presence of tannins, saponins, phenols, protein, flavonoids, glycosides, and alkaloids. Ethyl acetate for leaf and stem demonstrate the highest extractive values (18% and 13%), respectively. XRD peaks appeared at 30.21, 28.73, 205.73, 200.73, 380.07, 390.24, 490.11, and 450.33ο . This will be helpful to identify the ownership of herbal drugs by the diffraction peaks through crystal structures and atomic spacing. These parameters are crucial for drug identification, standardization, authentication, and drug designing. These studies also provided knowledge regarding therapeutic and nutraceutical importance of this plant. RESEARCH HIGHLIGHTS: The current pharmacognostic studies carried out on Rhododendron afghanicum can serve as a basis for compiling keys for finding the taxonomic identification and authentication of the said species by morphological, anatomical, and physicochemical features.

Genome-wide identification and characterization of major latex-like protein genes responsible for crop contamination in Cucurbita pepo.

Zucchini plants (Cucurbita pepo) accumulate persistent organic pollutants (POPs) at high concentrations in their aerial parts, and major latex-like proteins (MLPs) play crucial roles in their accumulation. MLPs bind to POPs in root cells, MLP-POP complexes are then translocated into xylem vessels, and POPs are transported to the aerial parts. We previously identified three CpMLP genes (MLP-PG1, MLP-GR1, and MLP-GR3) as transporting factors for POPs; however, other studies have shown that the genomes of several plant species contain more than 10 MLP genes, thus, further MLP genes responsible for POP accumulation may have been overlooked. Here, we investigated the number of CpMLP genes by performing a hidden Markov model search against the C. pepo genome database and characterized their effects on POP accumulation by performing the expression analysis in the organs and in silico structural analysis. The C. pepo genome contained 21 CpMLP genes, and several CpMLP genes, including MLP-PG1 and MLP-GR3, were highly expressed in roots. 3D structural prediction showed that all examined CpMLPs contained a cavity with a hydrophobic region, which facilitated binding to POPs. The present study provides insights regarding CpMLP genes responsible for POP accumulation.

The vessel wall thickness-vessel diameter relationship across woody angiosperms.

PremiseComparative anatomy is necessary to identify the extremes of combinations of functionally relevant structural traits, to ensure that physiological data cover xylem anatomical diversity adequately, and thus achieve a global understanding of xylem structure–function relations. A key trait relationship is that between xylem vessel diameter and wall thickness of both the single vessel and the double vessel+adjacent imperforate tracheary element (ITE).MethodsWe compiled a comparative data set with 1093 samples, 858 species, 350 genera, 86 families, and 33 orders. We used broken linear regression and an algorithm to explore changes in parameter values from linear regressions using subsets of the data set to identify a threshold, at 90‐µm vessel diameter, in the wall thickness–diameter relationship.ResultsBelow 90 µm diameter for vessels, virtually any wall thickness could be associated with virtually any diameter. Below this threshold, selection is free to favor a very wide array of combinations, such as very thick walls and narrow vessels in ITE‐free herbs, or very thin‐walled, wide vessels in evergreen dryland pioneers. Above 90 µm, there was a moderate positive relationship.ConclusionsOur analysis shows that the space of vessel wall thickness–diameter combinations is very wide, with selection apparently eliminating individuals with vessel walls “too thin” for their diameter. Most importantly, our survey revealed poorly studied plant hydraulic syndromes (functionally significant trait combinations). These data suggest that the full span of trait combinations, and thus the minimal set of hydraulic syndromes requiring study to span woody plant functional diversity adequately, remains to be documented.