Spongy Parenchyma Cells Research Articles

Effect of growth promotors on morphogenesis, photosynthetic apparatus, productivity and residual substances content in sweet pepper (Capsicum annuum) fruits

The use of plant growth promoting substances in order to optimize crop performance is one of the leading tasks of modern plant physiology. The effect of 0.005% 1-naphthaleneacetic acid (1-NAA), 0.005% gibberellic acid (GA3), 0.005% 6-benzylaminopurine (6-BAP) foliar treatment on morphogenesis, leaf parameters, photosynthetic pigments content, photosynthetic apparatus activity indices, and residual amounts of the used substances in the sweet pepper Capsicum annuum L. variety Antey fruits was investigated. The field experiment was laid on plots of 32 m2. The treatment of plants was carried out at the budding stage. Morphometric indices were determined at the flowering and fruit formation stages. The mesostructure of the middle tier leaves was studied at the fruit formation stage. The content of the chlorophylls was determined in the fresh leaf tissue by the spectrophotometric method. Indices of photosystem II (PSII) activity were determined by registration of chlorophyll fluorescence induction, using a portable single-beam fluorimeter. The assay of the residual content growth of promotors in the fruits was carried out on a Shimadzu GC gas chromatograph with a mass spectrometric detector – GCMS-QP2020 EI. It was revealed that treatment with GA3 increased plant height. All substances increased the number of leaves on the plant, their fresh and dry weight, the leaf area, and the canopy leaf area index. All growth promoting substances thickened leaf laminas due to the growth of chlorenchyma. GA3 and 6-BAP increased the volume of columnar parenchyma cells, and 1-NAA and GA3 increased the size of leaf spongy parenchyma cells. 6-BAP increased the total chlorophyll (a + b) content in the leaves, and under the GA3 treatment this index tended to decrease. 6-BAP increased the chlorophyll index of plants at the fruit formation stage, and GA3 decreased it at the flowering stage. The net photosynthetic rate increased under the influence of 1-NAA and 6-BAP, and decreased under GA3 treatment. GA3 reduced photorespiration and transpiration in leaves, 6-BAP increased transpiration, and 1-NAA decreased it. All substances increased dark respiration. Treatment with GA3 and 6-BAP reliably increased the maximum quantum efficiency of PSII photochemical reactions. 1-NAA and 6-BAP increased the actual quantum efficiency of PSII photochemistry. The coefficient of chlorophyll fluorescence photochemical quenching significantly increased at flowering under the application of 1-NAA, and tended to increase at the stage of fruit formation under the treatment of 1-NAA and 6-BAP. When GA3 was applied, the rate of chlorophyll fluorescence photochemical quenching was significantly reduced. The index of PSII reaction centers fraction that do not reduce the QB acceptor did not change with the use of 1-NAA and GA3 and tended to decrease after the use of 6-BAP. All growth promotors increased the whole plant dry weight. They reduced the net photosynthetic efficiency at the flowering stage, and at the stage of fruit formation it significantly increased under the treatment with 6-BAP. The 6-BAP caused the redistribution of plastic substances into the fruits due to the decrease in the dry weight of vegetative organs. Treatment with 1-NAA increased the proportion of root dry weight. 1-NAA, GA3 and 6-BAP increased the yield of fruits from one plant by 17%, 22% and 20% respectively due to the increase in the number of fruits per plant. The residual amounts of 1-NAA and 6-BAP in ripe sweet pepper fruits did not exceed the maximum permissible sanitary standards.

Microscopic investigation and pharmacognostic evaluation of leaves of Anemone rupicola Camb.

There is almost no scientific literature available on the phytochemistry and pharmacognosy of this plant so the basic aim of the study is to analyze pharmacognostic features of dried leaves of Anemone rupicola Camb. Morphology was studied by using the features like margins, shape, length, width, surface and so forth. For anatomical examination leaves were preserved in formalin acetic alcohol (FAA) and cutting the thin section of leaves and petiole with razor blade. Macroscopic characters of powdered drug were evaluated through organoleptic method. Qualitative phytochemical analysis was done by adopting the standard procedures. The antimicrobial activity of methanolic extract of Anemone rupicola Camb. was performed by Agar well diffusion method. The powder microscopic study showed epidermal cells, trichomes, various type of tracheids, pitted vessels, and sclerenchymatous fibers. Transverse cutting of leaves and petiole revealed the presence of different cells such as epidermis, palisade parenchyma, spongy parenchyma cells, aerenchyma, collenchyma, trichomes, and vascular bundles. The investigation of phytochemicals in distilled water, methanol and in ethanol solvent indicated the presence of various secondary compounds such as phenols, saponins, glycosides, alkaloids, tannins, cardiac glycosides, terpenoids, coumarins, and flavonoids. The methanolic extract of Anemone rupicola Camb. has potential as an antimicrobial agent. However, further studies are needed to confirm its efficacy and safety. This study can be used as powerful tool for the identification and authentication of this plant. For the purity and quality control these results will be helpful tool. This will also shed light into new areas where researchers can intervene in developing new drugs for future use. RESEARCH HIGHLIGHTS: Morphological Features of the Anemone rupicola Anatomical examination of leaves of Anemeone rupicola Microscopic features of powdered drug of leaves of Anemone rupicola Qualitative Phytochemical analysis of the leaves of Anemone rupicola.

Characteristics of Aluminum Accumulation and Distribution in Leaves of Different Ages in Camellia oleifera

Oil tea (Camellia oleifera Abel.), an important edible oil tree found in the acidic soil of south China, is tolerant to aluminum (Al); however, the mechanism via which it detoxifies Al remains unclear. The present study investigated the accumulation and distribution of Al and the changes in antioxidant components in C. oleifera leaves at different stages of growth. The analysis revealed that the content of Al in young, mature, and old leaves was 1.53, 7.49, and 12.04 g kg−1, respectively. In the leaves, Al was mainly accumulated in the cell wall, which accounted for 66.03%, 79.94%, and 86.51% of the total Al accumulation in young, mature, and old leaves, respectively. In the leaf cell wall, the Al content in hemicellulose increased from 54.22% to 81.72% with leaf age. The proportion of Al in the upper epidermis, lower epidermis, palisade, and spongy parenchyma cell walls increased with leaf age. The activity of antioxidant enzymes increased and showed a synergistic effect on Al stress with leaf age. The peroxidase activity was the highest in mature leaves, 2.3 times that in young leaves. Meanwhile, catalase and superoxide dismutase activities and total phenol content were the highest in young leaves. Correlation analysis showed that antioxidant system composed of catalase, superoxide dismutase and total phenol (CAT, SOD, and TP) was negatively correlated with the Al content in C. oleifera leaves. The malondialdehyde (MDA) content was positively correlated with Al content in C. oleifera leaves, indicating that the MDA in the leaves helped resist Al stress in C. oleifera. Thus, our findings suggest that the increase in antioxidant properties and modification of the cell wall contributed to Al detoxification in the Al hyperaccumulator C. oleifera.

Comparative leaf structural analysis of Nepeta nuda l. Plantlets, regenerated from cryopreserved shoot meristem and ex vitro-adapted plants

The leaf anatomy and chloroplast ultrastructure of Nepeta nuda L. plantlets regenerated in vitro from cryopreserved shoot apical meristem and in vitro-micropropagated plantlets were studied comparatively to assess whether cryoprocedure affected leaf morphogenesis. Both postcryo and in vitro plantlets failed to develop a distinguishable palisade layer, making the mesophyll appear homogeneous. Significant damage to the chloroplast envelope and substantial thylakoid ruptures were also observed. We assumed that the specific in vitro conditions more likely affected the structures than the cryotreatment itself. Light and transmission electron microscopy observations were also carried out on newly formed leaves of ex vitro-adapted plants. The examined leaf features were similar to those in the in situ plants – bifacial leaf lamina, double-layered palisade parenchyma, loosely arranged spongy parenchyma cells, and chloroplasts with intact envelope and evenly distributed throughout the stroma internal membrane system. The obtained histological and ultrastructural results revealed the retained morphogenetic potential of N. nuda plants and proved cryopreservation as a suitable method for long-term storage.

Cytoplasmic lipid droplets (LDs) occurrence in leaf tissues of different Coffea species: A new physiological trait in coffee

The present investigation aims to ascertain the presence of cytoplasmic lipid droplets (LDs) in different Coffea sp. leaf tissues. A detailed morpho-anatomical characterization, in addition to highlighting that the overall internal leaf tissue organization is independent of the coffee botanical species, put in evidence for the first time the presence of LDs in Coffea sp. leaves. Leaves from plant accessions of several coffee species, kept under greenhouse conditions, have been sampled in two different periods (January and June). Cytoplasmic LDs have been observed in all samples and they are mainly present as a single body, ranging from a minimum diameter of 1 µm to a maximum of 10 µm, detected in both palisade and spongy parenchyma cells of mesophyll tissue. In some case LDs are also sporadically observed in some epidermal cells in both abaxial or adaxial surface or in the subsidiary cells of stomata. Depending on season as well as coffee species, LDs show variability in terms of quantity, size, clustering and tissue distribution (presence in the mesophyll and/or epidermal tissue). The occurrence of LDs in a particular coffee leaf tissue is the prerequisite to further explore the physiological role of these organelles and reveal their possible functional benefits.

Effect of antigibberellins on morphogenesis, photosynthetic apparatus, productivity and their residual content in tomato fruits

The application of growth and development regulators on crops in order to optimize their production process is one of the leading tasks of modern plant physiology. Retardants – gibberellin inhibitors are widely used for this purpose. We investigated the effect of foliar treatment with EW-250, ССС-750 and 2-СEPA on morphogenesis, leaf apparatus, content of photosynthetic pigments, indices of chlorophyll fluorescence induction, CO2 gas exchange, and residual amounts of drugs in the fruits of tomato (Lycopersicon esculentum Mill.) Bobcat hybrid. The field experiment was laid on plots with an area of 33 m2. The treatment of the plants was carried out at the budding stage. Morphometric indices were determined at the stages of flowering and fruit formation. The chlorophylls content was determined in the raw material by the spectrophotometric method. Indices of photosystem II (PSII) photochemical activity were determined according to the parameters of chlorophyll fluorescence induction after a half-hour exposure of plants in the dark using a portable single-beam fluorimeter "Floratest". The determination of the residual content of retardants in the fruits was carried out on a Shimadzu GC gas chromatograph with a mass spectrometric detector – GCMS- QP2020 EI. All gibberellin inhibitors reduced linear plant size. The number of leaves on the plants decreased under 2-CEPA treatment, and increased after the application of EW-250. Treatment with 2-CEPA decreased, EW-250 significantly increased, and CCC-750 practically did not change the leaves’ fresh and dry weight. Leaf area and leaf index decreased under 2-CEPA treatment, but practically did not change when EW-250 and ССС-750 were applied. All antigibberellin drugs increased the leaf specific leaf weight and thickened the leaf lamina due to the growth of chlorenchyma cells. At the same time, growth inhibitors increased the volume of columnar parenchyma cells and practically did not change the size of spongy parenchyma cells. Retardants increased the chlorophylls content in leaves, while the ethylene producer 2-CEPA did not change this index. The plants’ chlorophyll index after treatment with drugs increased significantly. The whole plant dry weight increased under EW-250 treatment, decreased after 2-CEPA application, and did not change under CCC-750. It was established that the photosynthetic rate increased under the EW-250 treatment, both in the flowering stage and in the stage of fruit formation, while when using 2-CEPA and CCC-750, it occurred only at the stage of fruit formation. The most significant positive changes of PSII photochemical activity indices were observed under the use of EW-250. Under the action of the drug, the maximum and actual quantum efficiency of PSII increased, the linear electron transport accelerated, and the fraction of reaction centers that did not transfer electrons from the primary acceptor QA to QB decreased, at the same time the chlorophyll fluorescence decay coefficient significantly increased, which indicates an increase in the CO2 assimilation intensity. Retardants increased the proportion of the fruit in the whole plant dry weight. All growth regulators increased net photosynthetic efficiency. A significant increase in fruit yield occurred under EW-250 treatment. When using CCC-750, the index tended to increase, while under the influence of 2-CEPA the yield decreased. The residual amounts of EW-250 and CCC-750 in the fruits did not exceed the maximum permissible concentrations.

Mechanisms of hydraulic conductivity in the leaf galls of Meunieriella sp. (Cecidomyiidae) in Avicennia schaueriana (Acanthaceae): does vascularization explain the preferred sites of induction?

Intralaminar galls of Meunieriella result from ground tissue proliferation in leaves of Avicennia schaueriana, a typical halophytic mangrove. We tested if the preferred sites of gall induction were the midribs and secondary veins (SV) at the basal leaf portion, where the galls were expected to be largest; and if the vascular system in galls and adjacent regions was altered to favour water supply in galls, thus increasing their growth. Gall induction sites and gall sizes were quantified according to leaf portions and regions. Anatomical and histometric analyses in vascular and ground tissues of galls and adjacent regions were compared to equivalent regions of non-galled leaves. The galls were largest at basal sites on leaves, the midrib and SV. More galls occurred on the apical portion of the leaf, and on the leaf blade and secondary vein regions. Changes in shape and vascular system area, number and diameter of vessel elements were detected in both galls and adjacent regions. Fewer and smaller-sized vessel elements were observed in regions proximal to the galls and inside them. Gall size is not related with preferred induction sites, which could be explained by factors such as thermal balance. Alterations in the vascular system indicate reduced hydraulic conductivity in the xylem in the proximal region and inside galls, leading to water leakage to gall parenchyma cells. This compensatory mechanism explains the expansion and proliferation of water storage and spongy parenchyma cells in the galls, explaining the higher growth in more vascularized regions.

QTL analysis identified two major all-internodes solidness loci from a completely solid-stemmed spring wheat line.

The culms of solid-stemmed wheat cultivars are filled with "pith" - a parenchymatous tissue largely composed of soft, spongy, and compact parenchyma cells. Breeding solid-stemmed cultivars is the most effective way to decrease the detrimental impact of wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae) on wheat production. Althougha major solid stem gene has been previously identified from durum wheat, it produces an intermediate level of stem solidness in common wheat which is insufficient to provide the required level of WSS resistance. The maximum resistance is achieved when stems are totally filled with pith. Thus, to identify a secondary source of solidness in common wheat, we developed three mapping populations from wheat cvs. Sadash, 'AAC Innova' and 'AAC Cameron', each crossed separatelywith P2711, a completely solid-stemmed hexaploid wheat breeding line. All populations were genotyped using either wheat 15K or 90K Infinium iSelect SNP Assay and high-density linkage maps were generated from individual populations along with consensus maps for chromosomes 3B and 3D from all populations. 'Sadash/P2711' and 'AAC Innova/P2711' populations were subjected to extensive phenotyping in ≥3 environments followed by quantitative trait loci (QTL) analyses using population-specific and consensus linkage maps. We identified two major solid stem QTLs in the distal regions of chromosome arms 3BL and 3DL in both populations in addition to several population-specific or common minor QTLs. Internode-specific QTL analyses detected both major QTLs of chromosomes 3B and 3D across internodes, from top to bottom of the stalk, but minor QTLs were largely detected in upper or middle internodes. Our results suggest that both major QTLs are sufficient to develop highly solid-stemmed cvs; however, the minor loci, which additively enhance the pith expression, can be coupled with major genes to achieve a complete solid stem phenotype in common wheat. Comparative and haplotype analyses showed that the 3B locus is homoeologous to 3D, the former being mapped to a 1.1 Mb genomic region. Major QTLs identified in this study can be incorporated in modern wheat cultivars to achieve maximum WSS resistance from high pith expression.

Enhancement of Photosynthetic Capacity in Spongy Mesophyll Cells in White Leaves of Actinidia kolomikta.

Considering that Actinidia kolomikta bears abundant white leaves on reproductive branches during blossoming, we hypothesized that the white leaves may maintain photosynthetic capacity by adjustments of leaf anatomy and physiological regulation. To test this hypothesis, leaf anatomy, gas exchange, chlorophyll a fluorescence, and the transcriptome were examined in white leaves of A. kolomikta during flowering. The palisade and spongy mesophyll in the white leaves were thicker than those in green ones. Chloroplast development in palisade parenchyma of white leaves was abnormal, whereas spongy parenchyma of white leaves contained functional chloroplasts. The highest photosynthetic rate of white leaves was ~82% of that of green leaves over the course of the day. In addition, the maximum quantum yield of PSII (Fv/Fm) of the palisade mesophyll in white leaves was significantly lower than those of green ones, whereas Fv/Fm and quantum yield for electron transport were significantly higher in the spongy mesophyll of white leaves. Photosynthetic capacity regulation of white leaf also was attributed to upregulation or downregulation of some key genes involving in photosynthesis. Particularly, upregulation of sucrose phosphate synthase (SPS), glyeraldehyde-3-phosphate dehydrogenase (GAPDH) and RuBisCO activase (RCA) in white leaf suggested that they might be involved in regulation of sugar synthesis and Rubisco activase in maintaining photosynthetic capacity of white leaf. Conclusions: white leaves contained a thicker mesophyll layer and higher photosynthetic activity in spongy parenchyma cells than those of palisade parenchyma cells. This may compensate for the lowered photosynthetic capacity of the palisade mesophyll. Consequently, white leaves maintain a relatively high photosynthetic capacity in the field.

Morphogenesis, pigment content, phytohormones and yield of tomatoes under the action of gibberellin and tebuconazole

One of the main tasks of contemporary plant physiology is regulation of growth and development of cultivated plants in order to optimize the productive process. The scientific community focuses its attention on the use of natural activators and growth inhibitors. We investigated the effect of foliar treatment with 0.005% solution of gibberellic acid and 0.025% solution of the anti-gibberellic preparation tebuconazole on morphogenesis, leaf mesostructure, content of photosynthetic pigments, balance of endogenous phytobrybrides and lymphocyte B and productivity of tomatoes. The vegetation experiment was carried out in the conditions of soil-sand culture in vessels with a 10-liter volume. The treatment was carried out in the budding phase. Morphometric parameters were measured every 10 days. The mesostructure of the middle tier leaves was studied in the fruit formation phase, and the chlorophyll content was determined in the raw material by spectrophotometric method. Analytical determination of endogenous phytohormones – indolyl-3-acetic (IAA), gibberellic acid and abscisic (ABA) acids and cytokinins – zeatin (Z), zeatin-O-glucoside (ZG), zeatinribozide (Znila) and isopentenyladenosine (iPA) was performed by high performance liquid chromatography – mass spectrometry (HPLC-MS). With gibberellic acid treatment plant height increased significantly, while with tebuconazole it decreased. Gibberellic acid increased the number of leaves per plant, and tebuconazole did not change it. The preparations increased the number of leaf blades per leaf, the total number of leaf blades per plant, the weight of the raw material of leaves, the area of leaf blades and the area of the leaves at the end of the study period. The dry matter weight of stems and roots under the action of gibberellic acid increased, and during the treatment of tebuconazole decreased. Gibberellic acid increased the dry matter of the whole plant, and tebuconazole did not change it. Under the action of tebuconazole the content of chlorophyll in the leaves increased, while under the action of gibberellic acid it decreased. Both regulators increased the volume of columnar parenchyma cells. Gibberellic acid increased the size of spongy parenchyma cells, while tebuconazole did not change them. It is revealed that the action of exogenous gibberellic acid in stems and leaves increased the content of endogenous IAA and gibberellic acid, and tebuconazole decreased their content. The ABA content in stems and leaves increased with tebuconazole treatments and decreased with exogenous gibberellic acid. The total cytokinin content in the leaves was higher than in the stems in both the control and the experiment samples. Growth regulators induced an increase in the cytokinin pool in leaves and a decrease in stems. Gibberellic acid increased the content of all five forms of cytokinins in the leaves, and tebuconazole increased only two isoforms. In the stems under the action of both growth regulators the content of Z decreased and iP increased. The content of ZR and iPA in stems increased after the application of the retardant and decreased under the action of growth stimulant. The ZG content exceeded the control after gibberellic acid treatment and was in trace concentrations under the action of tebuconazole. Growth regulators optimized the productivity of tomato plants: under the action of gibberellic acid there was a considerable increase in the number of fruits per plant, and after the use of tebuconazole the average weight of one fruit significantly increased. The obtained results demonstrated that anatomical-morphological and structural-functional rearrangements in tomato plants under the action of exogenous gibberellic acid and tebuconazole occurred against the background of changes in the balance and distribution of endogenous hormones. Increased photosynthetic activity, stimulation of growth processes of some plant organs and inhibition of others increased the biological crop capacity.

MORPHOLOGICAL AND ANATOMICAL FEATURES OF THE STRUCTURE OF VEGETATIVE AND GENERATIVE ORGANS OF LYCIUM CHINENSE MILL. AND LYCIUM BARBARUM L. SOLANACEAE JUSS. IN THE CONDITIONS OF UZBEKISTAN

The characteristics of Lycium chinense Mill and Lycium barbarum L., species, taxonomy, origin and use in medicineare given. The adaptation of these plants in the conditions of the Botanical Garden of Tashkent, as well as in the conditions of the Namangan region, was studied. The morphological and anatomical structures of two species of the genus Lycium have been studied. The morphology and structure of vegetative and generative organs, which differ from each other in leaf shape and venation, are described. Leaf cells are studied in detail: the epidermis of the upper side has a smaller number of stomata, which makes it possible to reduce the evaporation of water in summer drought conditions. The spongy parenchyma is chlorophyllon-bearing. Calcium oxalate was found in palisade and spongy parenchyma cells. Conductive bundles of bicollateral type are numerous, consist of phloem and xylem. The center of the petiole has one vascular bundle with a closed bicollateral type. Parenchymal cells are thin-walled, but some have hydrocytic cells. The petiole of the leaf in a transverse section is of the parenchymal-fascicular type, has numerous parenchymas and vascular bundles. Collenchyma is located under the epidermis, based on osmotic phenomena. The stems are sclerified, helping to resist various environmental influences. It was found that with age, the cambium changes the anatomical structure of the stem, and also annually produces secondary xylem.The fruit of Lyciumchinense is a berry, syncarpous and 2-celled. Nucleoli were found in the epidermis. On a transverse section, the pericarp consists of several parenchymal cells, the walls of the epidermis are thickened and cutinized. The mesocarp consists of multi-row parenchymal cells. They are tangentially elongated in the outer layers, and rounded in the inner ones. Endocarp of irregular shape. The seeds of Lyciumchinense are large, round, and have a beak-shaped rib. The cells of the outer epidermis become lignified over time. The parenchyma of the intigument is enclosed between the epidermis. The perisperm is absent. The endosperm is of a cellular type, the endosperm cells contain oil droplets and aleurone grains. Based on the results, morphological-anatomical-histological features were determined. The data obtained can serve to identify plant materials, in environmental studies, as well as to determine diagnostic features.

Pharmacognostical, physicochemical and phytochemical evaluation of Huberantha senjiana (Annonaceae) leaf: An endemic tree of Gingee Hills Tamil Nadu India

Context: Huberantha senjiana (Annonaceae) is a small tree found in dry rocky soils. It is an endemic species native to the Gingee hills of the Villupuram district of Tamil Nadu, India. The literature survey provides no scientific evidence on its pharmacognostical as well as pharmacological aspect. Aims: To evaluate the detailed pharmacognostical, physicochemical, and phytochemical characters of H. senjiana leaves. Methods: The pharmacognostic evaluation, such as macroscopic and microscopic characters of fresh leaf and powder, was done. Physicochemical constants like moisture content, extractive values, ash values, foaming index, swelling index, and fluorescence analysis were carried out. The phytochemical screening test and elemental analysis of the powdered leaves were also studied. Results: Microscopy of the leaf revealed a single layer of square-shaped epidermal cells, the adaxial epidermal layer is apostomatic, and the abaxial epidermal layer is stomatiferous with paracytic stomata, an arch-shaped vascular bundle, clusters of prismatic crystals, spongy parenchyma cells, and palisade cells. Prismatic calcium oxalate crystals, fibers, epidermal trichomes, palisade mesophyll, xylem vessels, and a fragment of the epidermal cell with paracytic stomata were also identified in the microscopy of powdered samples. The phytochemical analysis of sequential extracts showed the presence of alkaloids, flavonoids, cardiac glycosides, terpenoids, carbohydrates, tannins, and steroids. The elemental analysis revealed the presence of heavy metals within the standard limit and trace elements in different concentrations. Conclusions: The pharmacognostical, physicochemical, and phytochemical data have been reported for the first time, which provides referential information for the right identification and standardization of this unexplored species.

The Morphological and Anatomical Traits of the Leaf in Representative Vinca Species Observed on Indoor- and Outdoor-Grown Plants

Morphological and anatomical traits of the Vinca leaf were examined using microscopy techniques. Outdoor Vinca minor and V. herbacea plants and greenhouse cultivated V. major and V. major var. variegata plants had interspecific variations. All Vinca species leaves are hypostomatic. However, except for V. minor leaf, few stomata were also present on the upper epidermis. V. minor leaf had the highest stomatal index and V. major had the lowest, while the distribution of trichomes on the upper epidermis was species-specific. Differentiated palisade and spongy parenchyma tissues were present in all Vinca species’ leaves. However, V. minor and V. herbacea leaves had a more organized anatomical aspect, compared to V. major and V. major var. variegata leaves. Additionally, as a novelty, the cellular to intercellular space ratio of the Vinca leaf’s mesophyll was revealed herein with the help of computational analysis. Lipid droplets of different sizes and aspects were localized in the spongy parenchyma cells. Ultrastructural characteristics of the cuticle and its epicuticular waxes were described for the first time. Moreover, thick layers of cutin seemed to be characteristic of the outdoor plants only. This could be an adaptation to the unpredictable environmental conditions, but nevertheless, it might influence the chemical composition of plants.

An overview of instrumented indentation technique for the study of micromechanical properties in food: A case study on bean seed coat

Food texture features depend on the structure–property-functionality relationship and mechanical properties. This work describes the application of the instrumented indentation technique (IIT) to determine the micromechanical properties of the bean seed coat evaluating different indentation loads. The bean seed coat's multilayer structure is composed of a cuticle (C), palisade cells (PAL), subepidermal pillar cells (SE), and spongy parenchyma cells (SP). Values of Ra and Rq revealed a rough surface due to the waxes and minerals present in the C. In the indentation tests, the C was indented at loads below 20 mN exhibiting values of hardness (H) and elastic modulus (E) of 383 ± 58 MPa and 11 ± 5 GPa, respectively. For PAL, when the load increased to 400 mN, H and E decreased to 198 ± 29 MPa and 3 ± 0.8 GPa, indenting 10% of the total thickness of the seed coat (103 ± 9 μm). The values of H and E decreased as the applied indentation load increased. This variability is influenced by the composition (waxes, lignin, condensed tannins, and CaOx crystals) and the effect of the layer-substrate system of multilayer structure of the seed coat.

Modulation of anatomical adaptations of leaves of Avicennia schaueriana (Acanthaceae) by a galling Meunieriella (Cecidomyiidae)

Globoid leaf galls with an abaxial concavity are induced by an undescribed species of Meunieriella Kieffer, 1909 (Cecidomyiidae) in Avicennia schaueriana Stapf & Leechm. ex Moldenke (Acanthaceae), a plant extremely adapted to mangroves. The gall-inducers may potentiate anatomical adaptations of host plants for producing a better shelter and food. We expected that some A. schaueriana important adaptations, such as salt glands, were potentiated in galls. Anatomical, histochemical and histometric analyses of non-galled leaves and galls were performed to assess which adaptive features are potentiated in gall development. Epidermis was not significantly altered in adaxial surface, and in the abaxial surface, hypertrophy of epidermal cells seems to compensate the increment in surface area during the gall development. Both the outer and inner gall compartments, separated by a sclerenchyma cap, maintain a dorsiventral arrangement. In such compartments, the proliferated water-storage parenchyma occupies the adaxial layers, followed by a palisade parenchyma, and elongated spongy parenchyma cells. Therefore, dorsiventrality is marked by the differential hyperplasia (predominant in adaxial layers) and cell hypertrophy (predominant in abaxial layers) in galls. Few layers of small nutritive cells are observed in contact to gall chamber, accumulating proteins, lipids, and sugars. The galling Meunieriella sp. can manipulate some adaptations to its own benefit, but A. schaueriana have strong constraints in leaf ontogenesis, possibly due to its specific adaptations to variable salinity and flooding. The proliferated water-storage parenchyma in gall may function as a site of ion accumulation, which could increase the bioaccumulation potential of the organ. The boundaries of host plant plasticity, related to specific environmental constraints, may be determinant in gall anatomical diversity.

Irradiance-driven 20-hydroxyecdysone production and morphophysiological changes in Pfaffia glomerata plants grown in vitro.

Pfaffia glomerata possesses potential pharmacological and medicinal properties, mainly owing to the secondary metabolite 20-hydroxyecdysone (20E). Increasing production of biomass and 20E is important for industrial purposes. This study aimed to evaluate the influence of irradiance on plant morphology and production of 20E in P. glomerata grown in vitro. Nodal segments of accessions 22 and 43 (Ac22 and Ac43) were inoculated in culture medium containing MS salts and vitamins. Cultures were maintained at 25 ± 2°C under a 16-h photoperiod and subjected to irradiance treatments of 65, 130, and 200μmolm-2s-1 by fluorescent lamps. After 30days, growth parameters, pigment content, stomatal density, in vitro photosynthesis, metabolites content, and morphoanatomy were assessed. Notably, Ac22 plants exhibited 10-fold higher 20E production when cultivated at 200μmolm-2s-1 than at 65μmolm-2s-1, evidencing the importance of light quantity for the accumulation of this metabolite. 20E production was twice as high in Ac22 as in Ac43 plants although both accessions responded positively to higher irradiance. Growth under 200μmolm-2s-1 stimulated photosynthesis and consequent biomass accumulation, but lowered carotenoids and anthocyanins. Furthermore, increasing irradiance enhanced the number of palisade and spongy parenchyma cells, enhancing the overall growth of P. glomerata. Graphical abstract.

Physiological responses and ginsenoside production of Panax ginseng seedlings grown under various ratios of red to blue light-emitting diodes

Ginseng, a semi-shade perennial plant, is greatly affected by light. However, light quality has only been studied in a few papers involving growth tests under monochromatic light or based on hairy root cultures. A plant factory with light-emitting diodes (LEDs) may provide high precision and standardization of ginseng seedlings for transplanting, and plant responses to light quality should be investigated for designing the optimal lighting conditions for this environment. In this study, various ratios of red light (R):blue light (B) were set from 100:0 to 0:100% at the same photosynthetic photon flux density of 75 μmol m−2 s−1. As R increased, the shoot length became longer from R75B25, resulting in the single treatment of R being 1.68 times that of B. Compared to monochromatic R or B treatments, the overall growth of ginseng seedlings in R50B50 treatment increased. In the mesophyll structure, mixed light as R50B50 or while LEDs increased starch grains, and only R treatment led to dense chloroplasts in palisade and spongy parenchyma cells. Increasing R ratios had negative effects on CO2 assimilation rate (AN), light-saturated net photosynthesis rate (Asat), and chlorophyll parameters. The higher the R ratio, the higher the ginsenoside content in leaves, while roots were less affected by spectral changes. Monochromatic R induced malformation and senescence of ginseng leaves, while the addition of 25% B was sufficient to prevent the abnormal development of leaves and dysfunctional photosynthetic operation of ginseng seedlings. The results suggest that combinations of R and B should be considered when designing artificial lighting systems for a closed-type plant factory since R affects the morphological characteristics and ginsenoside content of ginseng seedlings.

Nickel potentiates soybean resistance against infection by Phakopsora pachyrhizi

AbstractAsian soybean rust (ASR), caused by the fungus Phakopsora pachyrhizi, causes significant yield losses worldwide. Nickel (Ni) plays a key role in the metabolism of some profitable crops, such as soybeans, because it is a constituent of several biomolecules and is required for the catalytic process of several enzymes. This study investigated the effect of foliar Ni treatment on the potentiation of soybean cultivar TMG 135 resistance to P. pachyrhizi infection at the microscopic, biochemical, and molecular levels. The severity of ASR decreased by 35% in plants treated with Ni. The malondialdehyde concentration, an indicator of cellular oxidative damage, was high in the leaves of plants that were not treated with Ni and was linked to ASR severity and the extensive colonization of the palisade and spongy parenchyma cells by fungal hyphae. The lignin concentration, β‐1,3‐glucanase activity, and expression of the URE gene and the defence‐related genes PAL1.1, PAL2.1, CHI1B1, and PR‐1A were up‐regulated in Ni‐treated plants infected with P. pachyrhizi. The information provided by this study shows the great potential of Ni to increase the basal level of soybean resistance to ASR and to complement other control methods within the context of sustainable agriculture.

Salt stress effect on morphometrical and anatomical leaf traits of promising poplar biotypes

The purpose of the research was to determine the effect of short-term salt stress on the morphometric, anatomical and biochemical traits of fast-growing woody plants and to evaluate the promising poplar genotypes according to their degree of resistance. The experiments were conducted on five annual varieties in containers. The fourth leaf from the top of apical shoot, 80% of which corresponds to a maximum leaf area and high photosynthetic activity, was used in the experiment. The studies showed the nature of changes in the specific surface density and water content of the leaf of annual shoots. A short-term salt stress causes changes in leaf anatomy. Thus, the less stable genotype of poplar ‘Kitayskiy’ responds by the reduction of the leaf thickness. The changes in leaf anatomy of the experimental plants also include a decrease in height of the palisade and spongy parenchyma cells, which leads to the reduction of assimilation surface area and unproductive water loss. The study included analysis of changes in the proline concentration as a result of short-term salinization of the experimental plants. All samples showed a change in proline levels in response to stress, but most intense reaction was shown by genotypes ‘Veduga’ and ‘Hybrid e.s.-38’. In general, greater stability and plasticity at the initial stage of salinization is characteristic of poplars ‘Volosistoplodny’, ‘Sacrau-59’, ‘Hybrid e.s.-38’ and ‘Veduga’, which allows us to recommend them for reforestation and afforestation on irrigated soils.

THE SURFACE OF THE LEAF BLADE AS A FACTOR INFLUENCING THE SPIDER MITES DEVELOPMENT ON CUCUMBER

A comparative assessment of spider mite eggs development on the upper and under side of cucumber cotyledons has been made under laboratory experiments on the varieties Ginga F1 and Vyaznikovsky 37. Studies have been conducted on the cotyledons cut off from growing plants and placed on a wet cotton wool in the Petri dish. Mite eggs laid by females for five hours have been used for work. It has been shown that mites develop more slowly on the underside of cotyledons in comparison to the upper side when cotyledons are not exposed to spider mite. This may be due to the peculiarities of gas exchange on the abaxial and adaxial sides of leaves. It has been also found, that the mite embryonic development duration is increased, if occurs on the underside of the cotyledon , damaged by the spider mite within 1 day. Apparently, this is caused by the plant defense reactions to herbivory occurring increasingly on the lower side of cotyledons and associated with volatiles that has adverse effect on the mite eggs development. It is assumed that responses to the spider mites damage in the cucumber cotyledon leaves (in particular, those associated with the releasing of volatile compounds) are more characteristic for the spongy parenchyma cells than for the palisade cells in the leaf mesophyll.