Abstract: More than a quarter of the primary productivity on land, and a large fraction of the food that humans consume, is contributed by plants that fix atmospheric CO(2) by C(4) photosynthesis. It has been estimated that transferring the C(4) pathway to C(3) crops could boost yield by 50% and also increase water use efficiency and reduce the need for fertilizer, particularly in dry, hot environments. The high productivity of maize (Zea mays), sugarcane (Saccharum spp.) and several emerging bioenergy grasses is due largely to C(4) photosynthesis, which is enabled by the orderly arrangement, in concentric rings, of specialized bundle sheath and mesophyll cells in leaves in a pattern known as Kranz anatomy. Here we show that PIN, the auxin efflux protein, is present in the end walls of maize bundle sheath cells, as it is in the endodermis of the root. Since this marker suggests the expression of endodermal genetic programs in bundle sheath cells, we determined whether the transcription factor SCARECROW, which regulates structural differentiation of the root endodermis, also plays a role in the development of Kranz anatomy in maize. Mutations in the Scarecrow gene result in proliferation of bundle sheath cells, abnormal differentiation of bundle sheath chloroplasts, vein disorientation, loss of minor veins and reduction of vein density. Further characterization of this signal transduction pathway should facilitate the transfer of the C(4) trait into C(3) crop species, including rice.

Abstract: The soilborne fungal plant pathogen Verticillium longisporum invades the roots of its Brassicaceae hosts and proliferates in the plant vascular system. Typical aboveground symptoms of Verticillium infection on Brassica napus and Arabidopsis thaliana are stunted growth, vein clearing, and leaf chloroses. Here, we provide evidence that vein clearing is caused by pathogen-induced transdifferentiation of chloroplast-containing bundle sheath cells to functional xylem elements. In addition, our findings suggest that reinitiation of cambial activity and transdifferentiation of xylem parenchyma cells results in xylem hyperplasia within the vasculature of Arabidopsis leaves, hypocotyls, and roots. The observed de novo xylem formation correlates with Verticillium-induced expression of the VASCULAR-RELATED NAC DOMAIN (VND) transcription factor gene VND7. Transgenic Arabidopsis plants expressing the chimeric repressor VND7-SRDX under control of a Verticillium infection-responsive promoter exhibit reduced de novo xylem formation. Interestingly, infected Arabidopsis wild-type plants show higher drought stress tolerance compared with noninfected plants, whereas this effect is attenuated by suppression of VND7 activity. Together, our results suggest that V. longisporum triggers a tissue-specific developmental plant program that compensates for compromised water transport and enhances the water storage capacity of infected Brassicaceae host plants. In conclusion, we provide evidence that this natural plant–fungus pathosystem has conditionally mutualistic features.

Abstract: Heavy metals are transported to rice grains via the phloem. In rice nodes, the diffuse vascular bundles (DVBs), which enclose the enlarged elliptical vascular bundles (EVBs), are connected to the panicle and have a morphological feature that facilitates xylem-to-phloem transfer. To find a mechanism for restricting cadmium (Cd) transport into grains, the distribution of Cd, zinc (Zn), manganese (Mn), and sulphur (S) around the vascular bundles in node I (the node beneath the panicle) of Oryza sativa ‘Koshihikari’ were compared 1 week after heading. Elemental maps of Cd, Zn, Mn, and S in the vascular bundles of node I were obtained by synchrotron micro-X-ray fluorescence spectrometry and electron probe microanalysis. In addition, Cd K-edge microfocused X-ray absorption near-edge structure analyses were used to identify the elements co-ordinated with Cd. Both Cd and S were mainly distributed in the xylem of the EVB and in the parenchyma cell bridge (PCB) surrounding the EVB. Zn accumulated in the PCB, and Mn accumulated around the protoxylem of the EVB. Cd was co-ordinated mainly with S in the xylem of the EVB, but with both S and O in the phloem of the EVB and in the PCB. The EVB in the node retarded horizontal transport of Cd toward the DVB. By contrast, Zn was first stored in the PCB and then efficiently transferred toward the DVB. Our results provide evidence that transport of Cd, Zn, and Mn is differentially controlled in rice nodes, where vascular bundles are functionally interconnected.

Abstract: Identifying the consequences of grass blade morphology (long, narrow leaves) on the heterogeneity of gas exchange is fundamental to an understanding of the physiology of this growth form. We examined acropetal changes in anatomy, hydraulic conductivity and rates of gas exchange in five grass species (including C3 and C4 functional types). Both stomatal conductance and photosynthesis increased along all grass blades despite constant light availability. Hydraulic efficiency within the xylem remained constant along the leaf, but structural changes outside the xylem changed in concert with stomatal conductance. Stomatal density and stomatal pore index remained constant along grass blades but interveinal distance decreased acropetally resulting in a decreased path length for water movement from vascular bundle to stomate. The increase in stomatal conductance was correlated with the decreased path length through the leaf mesophyll. A strong correlation between the distance from vascular bundles to stomatal pores and stomatal conductance has been identified across species; our results suggest this relationship also exists within individual leaves.

Abstract: Xylem structure and function are well described in woody plants, but the implications of xylem organization in less-derived plants such as ferns are poorly understood. Here, two ferns with contrasting phenology and xylem organization were selected to investigate how xylem dysfunction affects hydraulic conductivity and stomatal conductance (gs). The drought-deciduous pioneer species, Pteridium aquilinum, exhibits fronds composed of 25 to 37 highly integrated vascular bundles with many connections, high gs and moderate cavitation resistance (P50 = −2.23 MPa). By contrast, the evergreen Woodwardia fimbriata exhibits sectored fronds with 3 to 5 vascular bundles and infrequent connections, low gs and high resistance to cavitation (P50 = −5.21 MPa). Xylem-specific conductivity was significantly higher in P. aqulinium in part due to its wide, efficient conduits that supply its rapidly transpiring pinnae. These trade-offs imply that the contrasting xylem organization of these ferns mirrors their divergent life history strategies. Greater hydraulic connectivity and gs promote rapid seasonal growth, but come with the risk of increased vulnerability to cavitation in P. aquilinum, while the conservative xylem organization of W. fimbriata leads to slower growth but greater drought tolerance and frond longevity.

Abstract: An antisense construct targeting the C4 isoform of NADP-malic enzyme (ME), the primary enzyme decarboxylating malate in bundle sheath cells to supply CO2 to Rubisco, was used to transform the dicot Flaveria bidentis. Transgenic plants (α-NADP-ME) exhibited a 34% to 75% reduction in NADP-ME activity relative to the wild type with no visible growth phenotype. We characterized the effect of reducing NADP-ME on photosynthesis by measuring in vitro photosynthetic enzyme activity, gas exchange, and real-time carbon isotope discrimination (Δ). In α-NADP-ME plants with less than 40% of wild-type NADP-ME activity, CO2 assimilation rates at high intercellular CO2 were significantly reduced, whereas the in vitro activities of both phosphoenolpyruvate carboxylase and Rubisco were increased. Δ measured concurrently with gas exchange in these plants showed a lower Δ and thus a lower calculated leakiness of CO2 (the ratio of CO2 leak rate from the bundle sheath to the rate of CO2 supply). Comparative measurements on antisense Rubisco small subunit F. bidentis plants showed the opposite effect of increased Δ and leakiness. We use these measurements to estimate the C4 cycle rate, bundle sheath leak rate, and bundle sheath CO2 concentration. The comparison of α-NADP-ME and antisense Rubisco small subunit demonstrates that the coordination of the C3 and C4 cycles that exist during environmental perturbations by light and CO2 can be disrupted through transgenic manipulations. Furthermore, our results suggest that the efficiency of the C4 pathway could potentially be improved through a reduction in C4 cycle activity or increased C3 cycle activity.

Abstract: Eugenia pyriformis Cambess., known as uvaia, is a species of Myrtaceae native to Brazil. Its leaves are used in folk medicine to treat gout because they possess the property of inhibiting xanthine oxidase, an enzyme involved in the conversion of xanthine into uric acid. The objective of this work was to study the leaf and stem morpho-anatomy of E. pyriformis, in order to contribute to what is known about the Brazilian flora, and this medicinal plant and potential vegetal drug. Samples of mature leaves and young stems were fixed and sectioned by freehand, or embedded in glycol methacrylate and sectioned with a microtome, and then stained. In addition, microchemical tests and scanning electron microscopy were performed. The leaf is simple, symmetric, elliptic-lanceolate, with an acute apex and base, and an entire margin. The epidermis is uniseriate and coated with a moderately thick cuticle. The stomata are anomocytic and inserted at the same level as the adjacent cells. Unicellular non-glandular trichomes are abundant on the abaxial surface. The mesophyll is dorsiventral. In transverse section, the midrib is plano-convex and the petiole is circular, and both of these structures have a single bicollateral vascular bundle. In the stem, the vascular cylinder consists of external phloem, xylem and internal phloem, traversed by narrow rays. Phenolic compounds, druses and prismatic crystals of calcium oxalate are also present in the leaf and stem.

Abstract: The aim of this study is to analyze the response of exogenous abscisic acid (ABA) application in plants grown under field conditions in semiarid zones in order to increase maize production. For this, it is necessary to understand the factors, such as the size and capacity of transport system involved in the mobilization and distribution of assimilates. The vascular transport capacity of ABA-treated and control plants was compared in terms of number of vascular bundles, phloem area per bundle, and the proportion of phloem in the ear peduncle of female inflorescences. This study showed that the application of exogenous ABA in field-grown maize under moderate drought allows a greater amount of maize production, an increase in the level of photosynthetic pigments, the carbohydrates remobilization to grain, and the capacity of this transport by an increase in the number of vascular bundles and the phloem area in peduncle. Evidence obtained in this study suggests that ABA could help improve agricultural production in rain-fed crops in which irrigation is not possible. This will allow us to follow a new technological strategy to increase the effective filling of organs during crops in unfavorable water conditions.

Abstract: In maize (Zea mays), Rubisco accumulates in bundle sheath but not mesophyll chloroplasts, but the mechanisms that underlie cell type-specific expression are poorly understood. To explore the coordinated expression of the chloroplast rbcL gene, which encodes the Rubisco large subunit (LS), and the two nuclear RBCS genes, which encode the small subunit (SS), RNA interference was used to reduce RBCS expression. This resulted in Rubisco deficiency and was correlated with translational repression of rbcL. Thus, as in C3 plants, LS synthesis depends on the presence of its assembly partner SS. To test the hypothesis that the previously documented transcriptional repression of RBCS in mesophyll cells is responsible for repressing LS synthesis in mesophyll chloroplasts, a ubiquitin promoter-driven RBCS gene was expressed in both bundle sheath and mesophyll cells. This did not lead to Rubisco accumulation in the mesophyll, suggesting that LS synthesis is impeded even in the presence of ectopic SS expression. To attempt to bypass this putative mechanism, a ubiquitin promoter-driven nuclear version of the rbcL gene was created, encoding an epitope-tagged LS that was expressed in the presence or absence of the Ubi-RBCS construct. Both transgenes were robustly expressed, and the tagged LS was readily incorporated into Rubisco complexes. However, neither immunolocalization nor biochemical approaches revealed significant accumulation of Rubisco in mesophyll cells, suggesting a continuing cell type-specific impairment of its assembly or stability. We conclude that additional cell type-specific factors limit Rubisco expression to bundle sheath chloroplasts.

Abstract: Considering bamboo as a 2-phase natural composite made up of vascular bundles (reinforcement or fiber) and matrixes (ground tissues) on the scale of micromechanics. By test of bamboo specimens and analysis of microscopic images of their cross sections, the distribution of vascular bundles along the axial and radial of bamboo culm were investigated. The relations between tensile properties of bamboo and its distribution of vascular bundles were studied. The results show that the vascular bundles are graded distributing along the radius of bamboo culm. The volume fraction of vascular bundles is larger near the outside, and attenuates rapidly to about 40 percent of that at the location away from outer side about 1/3 thickness of bamboo culm, and than slowly reduces to 0 near the inner side of culm. In axial direction, the volume fraction of vascular bundles in the bottom culm is smaller than that in the middle culm where the volume fraction is less variation, and reaches the largest value at the top culm. The tensile moduli and strength of bamboo are linearly related to the volume fraction of vascular bundles. The tensile moduli and the strength of vascular bundle are largely grater than that of matrix. The stiffness and the strength of bamboo are mainly offered by vascular bundles.

Abstract: Lucifer Yellow (LYCH) and carboxyfluorescein (CF) served in Medicago truncatula roots and root nodules as the markers of apoplastic and symplastic transport, respectively. The aim of this study was to understand better the water and photoassimilate translocation pathways to and within nodules. The present study shows that in damaged roots LYCH moves apoplastically through the vascular elements but it was not detected within the nodule vascular bundles. In intact roots, the outer cortex was strongly labeled but the dye was not present in the interior of intact root nodules. The inwards movement of LYCH was halted in the endodermis. When the dye was introduced into a damaged nodule by infiltration, it spread only in the cell walls and the intercellular spaces up to the inner cortex. Our research showed that in addition to the outer cortex, the inner tissue containing bacteroid-infected cells is also an apoplastic domain. Our results are consistent with the hypothesis that nodules do not receive water from the xylem but get it and photoassimilates from phloem. A comparison between using LYCH and LYCH followed by glutaraldehyde fixation indicates that glutaraldehyde is responsible for fluorescence of some organelles within root nodule cells. The influence of the fixation on nodule fluorescence has not been reported before but must be taken into consideration to avoid errors. An attempt was made to follow carboxyfluorescein (6(5) CF) translocation from leaflets into roots and root nodules. In root nodules, CF was present in all or a couple of vascular bundles (VB), vascular endodermis and some adjacent cells. The leakage of CF from the VBs was observed, which suggests symplastic continuity between the VBs and the nodule parenchyma. The lack of CF in inner tissue was observed. Therefore, photoassimilate entry to the infected region of nodule must involve an apoplastic pathway.

Abstract: 【Objective】 With the decreasing of the solar radiation in China,effects of shading(low light stress) on stalk morphology and microstructure of summer maize were studied to provide a theoretical basis for summer maize to adapt the current climatic condition of insufficient illumination.【Method】 Summer maize was grown under the shading condition with a shading degree of 60%.Three shading treatments were designed in growing season ranged from tasseling to maturity(S1),from jointing to tasseling stage(S2) and whole growing period(S3),respectively.Two summer maize cultivars Denghai605(DH605) and Zhengdan958(ZD958) were used as experimental materials.Effects of shading in different growing seasons on stem characters and lodging property of summer maize were investigated.【Result】 Results showed that plant height,ear height,leaf area index,the third internodes length,cross sectional area of stem,and stalk rind penetration strength reduced significantly after shading,and the response to different shading stages showed: S1S2S3.Compared to CK,stalk rind penetration strength of DH605 and ZD958 reduced by 22.23% and 24.41%,respectively.Stem rind thickness,vascular bundle number,the area of the central vascular bundle,xylem and phloem reduced significantly.Lodging property in fields increased significantly,and the lodging rate of DH605 and ZD958 in S3 were 36.5% and 24.7%,respectively.Furthermore,grain yield,kernel number per ear and harvest ear number reduced significantly.Barrenness increased and grain yield of S3 reduced.【Conclusion】Shading had significant effects on stem form.Stem lodging resistance was also reduced by decreased basal internode length,diameter,puncture strength,hard skin tissue thickness and vascular bundle number,thus influencing yield formation.Shading before anthesis had a great influence on the lodging rate.

Abstract: In the west of the Province of Leon (Spain), five species of gall-dwelling aphids, or greenflies, trigger the formation of different galls in Pistacia terebinthus: Forda formicaria, F marginata, Paracletus cimiciformis, Geoica utricularia and Baizongia pistaciae In the research presented here, a microscopic study was carried out of the wall of galls induced by the latter two species, G utricularia and B pistaciae Galls induced by the first three species had already been studied previously by the same author All the species of aphids mentioned above are included in the Eriosomatinae, Fordini Among these, some authors further claim that it is possible to distinguish two clades: Forda and Paracletus would be included in one of these, whilst Geoica and Baizongia would be included in the other The results of this study show that the walls of galls induced by G utricularia and B pistaciae present collateral vascular bundles Specifically, there are two such vascular bundles: one distant from the chamber and the other separated from it by only a very few cells The phloem in the latter vascular bundle is oriented towards the chamber Furthermore, in the two galls studied, the chamber is lined with a lattice-like structure with hollows These microscopic observations have enabled the walls of the galls studied to be differentiated from those triggered by Forda and Paracletus These latter present a single vascular bundle, with the xylem oriented towards the chamber, whilst the surface of the chamber lining has a quilted appearance and lacks openings This research provides data from microscopy to support the existence of two clades among the Fordini

Abstract: In C4 plants, such as maize, the photosynthetic apparatus is partitioned over two cell types called mesophyll (M) and bundle sheath (BS), which have different structure and specialization of the photosynthetic thylakoid membranes. We characterized protein phosphorylation in thylakoids of the two cell types from maize grown under either low or high light. Western blotting with phosphothreonine antibodies and ProQ phosphostaining detected light-dependent changes in the protein phosphorylation patterns. LC-MS/MS with alternating CID and electron transfer dissociation sequencing of peptide ions mapped 15 protein phosphorylation sites. Phosphorylated D2, CP29, CP26, Lhcb2 proteins, and ATPsynthase were found only in M membranes. A previously unknown phosphorylation site was mapped in phosphoenolpyruvate carboxykinase from the BS cells. Phosphorylation stoichiometry was calculated from the ratios of normalized ion currents for phosphorylated to nonphosphorylated peptide pairs from the D1, D2, CP43, and PbsH proteins of photosystem II (PSII). Every PSII in M thylakoids contained on average 1.5 ± 0.1 or 2.3 ± 0.2 phosphoryl groups in plants grown under either low or high light, while in BS membranes the corresponding numbers were 0.25 ± 0.1 or 0.7 ± 0.2, respectively. It is suggested that the phosphorylation level, as well as turnover of PSII depend on the structure of thylakoids.

Abstract: Summary An HD-Zip IV gene from wheat, TaGL9, was isolated using a Y1H screen of a cDNA library prepared from developing wheat grain. TaGL9 has an amino acid sequence distinct from other reported members of the HD-Zip IV family. The 3¢ untranslated region of TaGL9 was used as a probe to isolate a genomic clone of the TaGL9 homologue from a BAC library prepared from Triticum durum L. cv. Langdon. The full-length gene containing a 3-kb-long promoter region was designated TdGL9H1. Spatial and temporal activity of TdGL9H1 was examined using promoter-GUS fusion constructs in transgenic wheat, barley and rice plants. Whole-mount and histochemical GUS staining patterns revealed grain-specific expression of TdGL9H1. GUS expression was initially observed between 3 and 8 days after pollination (DAP) in embryos at the globular stage and adjacent to the embryo fraction of the endosperm. Expression was strongest in the outer cell layer of the embryo. In developed wheat and barley embryos, strong activity of the promoter was only detected in the main vascular bundle of the scutellum, which is known to be responsible for the uptake of nutrients from the endo- sperm during germination and the endosperm-dependent phase of seedling development. Furthermore, this pattern of GUS staining was observed in dry seeds several weeks after harvesting but quickly disappeared during imbibition. The promoter of this gene could be a useful tool for engineering of early seedling vigour and protecting the endosperm to embryo axis pathway from pathogens during grain desiccation and storage.

Abstract: Poplar 741 [Populus alba × (P. davidiana + P. simonii) × P. tomentosa] leaves were rooted within 8 days when cultured on 1/2 MS medium. The spatial distribution of endogenous indole-3-acetic acid (IAA) and its dynamic changes in the rhizogenesis were investigated, using an immunohistochemical approach. Anatomical analyses showed that the root primordia arose from vascular cambium cells in the basal regions of the petioles of the leaves. Before root induction, immunostaining patterns showed a basipetally decreasing gradient of IAA along the leaves. Three days after induction, the IAA immunostaining pattern observed along the leaves was high at both ends and low in the middle. And IAA in the basal regions of the petiole was distributed mainly in the vascular bundles. Localized application of 2,3,5-triiodobenzoic acid (TIBA) on laminas of the leaves delayed the accumulation of IAA in the vascular bundles of the basal regions of the petioles, but not in the mesophyll of the laminas. These data indicate that an accumulation of IAA in the vascular bundles of the basal regions of the petioles induces the occurrence of rhizogenesis of poplar leaves. And IAA accumulated in the vascular bundle of the basal region of the petiole results from its polar transportation from mesophyll of the laminas, rather than by in situ IAA generation.

Abstract: Stem diameter in Gallesia integrifolia (Spreng.) Harms (Phytolaccaceae) increases by forming concentric rings of xylem alternating with phloem, which show frequent anastomoses. After a period of primary growth and the formation of first (normal) ring of vascular cambium, further successive rings are initiated outside this cambium. The second ring of cambium originates from the pericycle parenchyma located between the proto-phloem, and the pericycle fibres. Each cambium produces centripetally secondary xylem and centrifugally secondary phloem. Differentiation of xylem precedes that of phloem and the first elements formed are always xylem fibres. Structurally, the vascular cylinder is composed by successive rings of secondary xylem and phloem. These rings are separated by wide bands of conjunctive parenchyma tissue. Presence of collateral vascular bundles with irregular orientation is observed in the region of anastomoses of two or more bands of conjunctive tissue. These bundles are surrounded by isodiametric, lignified and thick-walled cells. In some of the cambial rings, occurrence of polycentric rays was also noticed; these rays are tall, and characterized by the presence of meristematic regions that differentiated into thick-walled elements of secondary xylem. Origin and development of the successive cambia and the structure of xylem are discussed.

Abstract: The aim of this study was to relate the leaf anatomical characteristics of Brachiaria decumbens ('Surinam grass') and Brachiaria plantaginea ('Alexandergrass') to herbicide sensitivity, at three developmental stages. The plants were sown in plastic pots filled with agricultural soil and kept in a greenhouse. The blade median portion of the third- expanded leaf, counted from the stem basis, was sampled, considering three developmental phases: stage 1 (plants presenting 4-6 leaves), stage 2 (plants presenting 3-4 tillers) and, stage 3 (adult plants in the beginning of flowering). The following leaf anatomy descriptors were quantified in the region of the keel (midrib) and wing (a portion between the midrib and the blade margin): transversal section area; percentages of epidermal cells in the adaxial and abaxial surfaces, sclerenchyma, vascular bundle sheath, vascular bundle, and parenchyma; leaf thickness; distance between vascular bundles; stomatal length; number of stomata and trichome (short and long). The values obtained were analyzed using multivariate statistical tests (Cluster Analysis and Principal Component Analysis). The leaf quantitative anatomical descriptors allowed differentiating stage 3 from the other stages as the least sensitive to the action of post-emergence herbicides.

Abstract: We studied the petiole structure of twelve American species of Pteris: P. ciliaris, P. cretica, P. deflexa, P. denticulata, P. ensiformis, P. exigua, P. inermis, P. multifida, P. mutilata, P. quadriaurita, P. tristicula and P. vittata, using both light and scanning electron microscopy. We found that petioles are characterized externally by the presence of an adaxial groove and two dorsal-lateral ventilation areas. Internally, petioles are monostelic V-, U- or inverted-Ω-shaped axes. The vascular system is surrounded by one endodermis cell layer and 1–3 pericycle strata. We propose a classification of the vascular bundles into four types considering their shape, the shape of the xylem ends, the number of protoxylem zones and the presence of parenchyma bands in the xylem.

Abstract: In vitro plant culture under conventional heterotrophic conditions promotes the development of certain undesirable morpho-physiological characteristics, such as reduced epicuticular wax deposition and mesophyll differentiation, rudimentary vascular bundles and little control of stomata opening and closing. Silicon is a beneficial element for plants and affects anatomical characteristics of leaf surface. This study analyzed morphological differences in banana plant cultivar ‘Maca’ plants as a result of the use of silicon added to the medium for in vitro cultivation. Shoots of banana plants cultivar ‘Maca’ established in vitro were inoculated on MS, supplemented with 30 g L-1 sucrose, 1 mg L-1 NAA (naphthaleneacetic acid) and solidified with 1.8 g L-1 Phytagel. Three sources of silicate were added to the MS medium, sodium silicate, potassium silicate or calcium silicate at 1 g L-1, and MS medium without silicate, as the control treatment. The experimental design was completely randomized with five replications. After 45 days, anatomical characteristics and photosynthetic and transpiration rates were evaluated. The addition of calcium silicate resulted in greater thickness of upper and lower epidermis, mesophyll, palisade parenchyma and increased photosynthetic rate. The use of silicon improved micropropagated anatomy of banana plant cultivar ‘Maca’ leaves.

Abstract: To clarify the diversity in funicular internal structures in Leguminosae, 59 legume species (classified into 46 genera, 20 tribes, and 3 subfamilies) were examined by a paraffin-sectioning method. The vascular bundles of legume funicles were clarified as collateral, amphicribral, or amphivasal. In species in which the funicular vascular bundle was collateral throughout the funicle, the xylem is positioned at the pericarpial side in the basal part of the funicle, and the xylem was always positioned at the micropylar side of the phloem in the apical end of the funicles. Whenever the seed direction (from hilum to the micropyle) faces the stylar side, the funicular vascular bundle appears to twist between the basal and the apical part of the funicle. This twist would involve a rotation of the seeds (ovules) during seed (ovule) development. This also may mean that the direction (from hilum to the micropyle) of legume seeds originally faces the pericarp.

Abstract: The aim of this work was to evaluate the control efficacy of diquat, glyphosate, and imazapyr and the anatomic leaf blade changes caused by these herbicides in B. subquadripara. The plants were grown in reservoirs under field conditions, and, after reaching the full vegetative development stage, were sprayed with solutions of diquat at 400 g ha'1 , glyphosate at 4,320 g ha'1combined with Aterbane at 0.5% v v1, and imazapyr at 750 g ha'1 . A control without herbicide was used. Control evaluations were carried out, followed by evaluation of the anatomic quantitative characteristics of the central vein and intervein regions of the leaf blade, as well as of the stem region: adaxial and abaxial epidermis %, endoderm %, vascular bundle %, aerenchyma lacunas %, parenchyma and leafthickness %, epidermal stem %, and vascular cambium and stem diameter %. The herbicides diquat and imazapyr promoted the largest number of changes in the quantitative anatomic characters of the midrib and intervein regions of the leaf and stem regions of the plants. However, with the exception of diquat, the herbicides were effective in controlling the B. subquadripara plants. All the herbicides allowed plant re-growth.

Abstract: This study presents the characterization of parenchyma and vascular bundle of oil palm ( Elaeis guineensis Jacq.) trunks harvested in Ladang Pelam, Kedah, Malaysia. Samples cut from outer, middle, and inner parts of the trunks were stored in a room at a temperature of 29 ° C for 0, 45, and 60 days prior to any tests. Parenchyma cells and vascular bundles from each sample were manually separated for microscopic analysis. Both light microscopes and scanning electron microscope were employed to determine cell type, their distribution, and modification as a function of storage time. Based on the results of this work, the outer parts of the trunks had larger amount of vascular bundles than the inner and middle parts. Overall moisture content of the samples taken from the inner part of the trunks is significantly higher than other parts. It appears that the amount of parenchyma cells decreases while the vascular bundle increases in all three parts of the trunks with increasing storage time.

Abstract: Taking bamboo as a 2-phase composite consisting of vascular bundles and matrix,the distribution of vascular bundles and the relationship between the tensile mechanical performance of bamboo and volume ratio of vascular bundles were studied by the microscopic image analysis and tensile mechanical test.The results show that the area of single vascular bundle increases gradually from the outer to the inner and the change trend is gentle when closing the inner of bamboo.The volume ratio of vascular bundles which increases from the inner to the outer becomes higher as the height of bamboo increases.The linear relationship between the tensile mechanical performance of bamboo and volume ratio of vascular bundles is revealed.Thus,the theoretical foundation for controllability of mechanical performance of bamboo is laid.