Large Vascular Bundles Research Articles

Evaluation of Large Vascular Bundle of Panicle Neck Internode of Rice Seed Aggregate and Rice Straw Aggregate Excavated from the Remains by X-ray CT Measuring

Evaluation of Large Vascular Bundle of Panicle Neck Internode of Rice Seed Aggregate and Rice Straw Aggregate Excavated from the Remains by X-ray CT Measuring

Relationship Between the Vascular Bundle Structure of Panicle Branches and the Filling of Inferior Spikelets in Large-Panicle Japonica Rice.

The vascular bundles of rice panicles serve to connect the source and the sink, as well as serving as a channel for the transportation of materials. In this study, two homozygous japonica rice strains were used as materials. The vascular bundle structures of the branches in different positions within a rice panicle were observed, and their cross-sectional areas were calculated. In addition, the ultrastructure of the central large vascular bundle (LVB) phloem in the rachillae of superior spikelets (SS) and inferior spikelets (IS) was observed during the grain filling period. Moreover, the soluble sugar and protein contents of the SS and IS rachillae were also measured to study whether the differences in the structure of vascular bundles of the branches were related to the plumpness of grain at different positions. The results showed that vascular bundle cross-sectional areas of the basal primary branches were greater than those in the upper primary branches. Moreover, there was little difference in the areas of vascular bundles between the basal secondary branches and upper secondary branches. However, the vascular bundle areas of the IS rachillae were lower than those in the SS rachillae. Therefore, we believe that the poor vascular tissue channel of the IS rachillae could be the limiting factor in IS plumpness. The results also showed that a similar time course in the degradation pattern of some organelles of the sieve elements and companion cells in central LVB was observed in the SS rachillae and IS rachillae during the grain filling period. Compared with the IS rachillae, more abundant mitochondria and plasmodesmata were found in the companion cells of SS rachillae at the beginning of the filling stage, while no significant differences between SS and IS rachillae were identified at the middle and late filling stages, which implies that the SS rachillae were relatively more effective at transportation compared with the IS rachillae at the initial filling stage. Therefore, the undeveloped vascular bundles of the IS rachillae and their poor physiology and lack of ability to transport at the initial filling stages could be the limiting factor in IS plumpness.

SDG128 is involved in maize leaf inclination.

Maize leaf angle (LA) is a complex quantitative trait that is controlled by developmental signals, hormones, and environmental factors. However, the connection between histone methylation and LAs in maize remains unclear. Here, we reported that SET domain protein 128 (SDG128) is involved in leaf inclination in maize. Knockdown of SDG128 using an RNA interference approach resulted in an expanded architecture, less large vascular bundles, more small vascular bundles, and larger spacing of large vascular bundles in the auricles. SDG128 interacts with ZmGID2 both invitro and invivo. Knockdown of ZmGID2 also showed a larger LA with less large vascular bundles and larger spacing of vascular bundles. In addition, the transcription level of cell wall expansion family genes ZmEXPA1, ZmEXPB2, and GRMZM2G005887; transcriptional factor genes Lg1, ZmTAC1, and ZmCLA4; and auxin pathway genes ZmYUCCA7, ZmYUCCA8, and ZmARF22 was reduced in SDG128 and ZmGID2 knockdown plants. SDG128 directly targets ZmEXPA1, ZmEXPB2, LG1, and ZmTAC1 and is required for H3K4me3 deposition at these genes. Together, the results of the present study suggest that SDG128 and ZmGID2 are involved in the maize leaf inclination.

Enhanced Myometrial Vascularity: Case Presentation and Review

<h3>Study Objective</h3> To describe the etiology of arteriovenous malformations (AVM) and enhanced myometrial vascularity (EMV) and review updates in management for patients with retained products of conception (RPOC) associated with EMV through a case presentation. <h3>Design</h3> The etiology, symptoms, imaging findings/interpretation, and updates in management based on symptoms are reviewed in detail. <h3>Setting</h3> Tertiary referral center. <h3>Patients or Participants</h3> Eight weeks following suction dilation and curettage (D&C) for an incomplete abortion, a 28-year-old G1P0 patient presented with RPOC, menorrhagia and an acute drop in hemoglobin to an outside facility. After a diagnosis of a uterine AVM was made, she was transferred to our facility for further care. <h3>Interventions</h3> After transfer to our center, ultrasound demonstrated RPOC, with prominent internal vasculature containing peak systolic velocity (PSV)>20 cm/sec. A diagnosis of EMV was made. An MRI confirmed prominent serpentine vessel at the endometrium and in the RPOC. Due to her anemia, she underwent a uterine artery embolization (UAE) followed by suction D&C. Hysteroscopy was performed before and after suction D&C and following curettage, a large vascular bundle was appreciated at the surface of the endometrium. <h3>Measurements and Main Results</h3> The patient presented to clinic 2 weeks post operatively with resolution of AUB symptoms and a negative Beta hCG. <h3>Conclusion</h3> The management of patients with EMV is dependent on the extent of their symptoms. If significant bleeding is present, surgical management is required. Previous reports suggested that patients with EMV and RPOC should undergo UAE prior to D&C, but more recent studies suggest that D&C may be initiated without UAE, as EMV associated with RPOC may be a normal transient placentation phenomenon and have less risk of hemorrhage than previously suspected. Each patient requires individualized management based on symptoms, signs, imaging, and plans for future fertility. The ideal management of patients with RPOC and EMV remains to be determined.

Genome-Wide Association Study of Vascular Bundle-Related Traits in Maize Stalk.

The vascular bundle plays an important role in nutrient transportation in plants and exerts great influence on crop yield. Maize is widely used for food, feed, and fuel, producing the largest yield in the world. However, genes and molecular mechanism controlling vascular bundle-related traits in maize have largely remained undiscovered. In this study, a natural population containing 248 diverse maize inbred lines genotyped with high-throughput SNP markers was used for genome-wide association study. The results showed that broad variations existed for the vascular bundle-related traits which are subject to genetic structure and it was suitable for association analysis. In this study, we identified 15, 13, 2, 1, and 5 SNPs significantly associated with number of small vascular bundle, number of large vascular bundle, average area of single small vascular bundle, average area of single large vascular bundle, and cross-sectional area, respectively. The 210 candidate genes in the confidence interval can be classified into ten biological processes, three cellular components, and eight molecular functions. As for the Kyoto Encyclopedia of Genes and Genomes analysis of the candidate genes, a total of six pathways were identified. Finally, we found five genes related to vascular development, three genes related to cell wall, and two genes related to the mechanical strength of the stalk. Our results provide the further understanding of the genetic foundation of vascular bundle-related traits in maize stalk.

Enhanced myometrial vascularity: case presentation and review

To describe the etiology of arteriovenous malformations (AVM) and enhanced myometrial vascularity (EMV), and review updates in management for patients with retained products of conception (RPOC) associated with EMV through a case presentation. A 6-minute narrated video discusses the recent distinction between EMV and AVM. The etiology, symptoms, imaging findings/interpretation, and management based on symptoms are reviewed in detail. As this represents a single case report, it does not meet the definition of research according to the regulations at 45 CFR 46.102(l); therefore, institutional review board approval was not required. Tertiary referral center. Eight weeks after suction dilation and curettage (D&C) for an incomplete abortion, a 28-year-old gravida 1, para 0 patient presented to an outside facility with RPOC, menorrhagia, and an acute decrease in hemoglobin. After uterine AVM was diagnosed, she was transferred to our facility for further care. After transfer to our center, ultrasound demonstrated RPOC, with prominent internal vasculature containing peak systolic velocity >20 cm/s. A diagnosis of EMV was made. Magnetic resonance imaging confirmed a prominent serpentine vessel at the endometrium and RPOC within the uterine cavity (Fig.1). Due to her anemia, she underwent uterine artery embolization (UAE) followed by suction D&C (Fig.2). Hysteroscopy was performed before and after suction D&C and after curettage, a large vascular bundle was appreciated at the surface of the endometrium. None. The patient presented to the clinic 2 weeks postoperatively with the resolution of abnormal uterine bleeding symptoms and a negative β-human chorionic gonadotropin test. Management of patients with EMV is dependent on the extent of their symptoms. If significant bleeding is present, surgical management is required. Previous reports suggested that patients with EMV and RPOC should undergo UAE before D&C, but more recent studies suggest that D&C may be initiated without UAE, as EMV associated with RPOC may be a normal transient placentation phenomenon and have less risk of hemorrhage than previously suspected. However, in patients with significant preoperative bleeding and/or anemia, we propose that UAE should still be considered. Each patient requires individualized management based on symptoms, signs, imaging, and plans for future fertility. The ideal management of patients with RPOC and EMV remains to be determined.

Yield-enhancing SPIKE allele from the aus-subtype indica rice and its allele specific codominant marker

Improving spikelet number without limiting panicle number is an important strategy to increase rice productivity. In this study, a spikelet number enhancing SPIKE-allele was identified from the aus subtype indica rice, cv. Bhutmuri, which has an identical japonica like corresponding sequence including a retrotransposon sequence, usually absent in indica genotypes, like IR64. An allele-specific singletube PCR-based codominant marker targeting an A/G single-nucleotide polymorphism (SNP) at the 3'UTR was identified for easier genotyping. The yield enhancing ability of the Bhutmuri-SPIKE allele carrying RILs and NILs over IR64-SPIKE allele carrying alleles was due to increased number of filled grains/panicle. More than three times higher abundance of SPIKE transcripts was observed in Bhutmuri and NILs carrying this allele compared with IR64 and its allele carrying NILs. Higher rate of photosynthesis at more than 900 μmolm-2s-1 light intensity and more than six small vascular bundles between the two large vascular bundles in the flag leaves of Bhutmuri and its allele carrying NILs were also observed. The identified SPIKE allele and the marker associated with it will be useful for increasing the productivity of rice by marker-assisted breeding.

Microstructure evidence of rice lodging resistance based on quantitative X‐ray microtomography

AbstractEven though lodging seriously affects the growth and development of rice (Oryza sativa L.) little is known about the stem and root microstructural characteristics of lodging resistant and non‐lodging resistant rice. In this study, one lodging resistant rice variety lingliangyou238 (R1), and two non‐lodging resistant rice varieties, luliangyou996 (S1) and zhuliangyou819 (S2), were used to conduct synchrotron‐based X‐ray micro‐computed tomography. We found that the lodging resistant rice variety R1 had a third internode (N3) length that was reduced by 37.4% compared to S1. Meanwhile, the area of stem cross section, area of the medullary cavity, and the number of large and small vascular bundles in the N3 of R1 increased by 73.56, 73.10, 18.55, and 17.74%, respectively, compared to S2. In the 3D structure, there are many pore structures in the inner wall of the rice stalk. Quantitative analysis showed that the ratio of length/width of the pores of R1 was lower than S1 and S2. In the fourth internode, the volume and surface area of the large vascular bundle vessel of R1 was greater than S1 and S2. In the root system, we found that R1 had more cortical cells, and its length/width value was lower than S1 and S2. Our findings implied that besides the 2D level, more 3D information is needed to reveal the relationship between lodging and the spatial structure of the crop.

Coleataenia prionitis, a C4-like species in the Poaceae.

C4-like plants represent the penultimate stage of evolution from C3 to C4 plants. Although Coleataenia prionitis (formerly Panicum prionitis) has been described as a C4 plant, its leaf anatomy and gas exchange traits suggest that it may be a C4-like plant. Here, we reexamined the leaf structure and biochemical and physiological traits of photosynthesis in this grass. The large vascular bundles were surrounded by two layers of bundle sheath (BS): a colorless outer BS and a chloroplast-rich inner BS. Small vascular bundles, which generally had a single BS layer with various vascular structures, also occurred throughout the mesophyll together with BS cells not associated with vascular tissue. The mesophyll cells did not show a radial arrangement typical of Kranz anatomy. These features suggest that the leaf anatomy of C. prionitis is on the evolutionary pathway to a complete C4 Kranz type. Phosphoenolpyruvate carboxylase (PEPC) and pyruvate, Pi dikinase occurred in the mesophyll and outer BS. Glycine decarboxylase was confined to the inner BS. Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) accumulated in the mesophyll and both BSs. C. prionitis had biochemical traits of NADP-malic enzyme type, whereas its gas exchange traits were close to those of C4-like intermediate plants rather than C4 plants. A gas exchange study with a PEPC inhibitor suggested that Rubisco in the mesophyll could fix atmospheric CO2. These data demonstrate that C. prionitis is not a true C4 plant but should be considered as a C4-like plant.

Leaf Response to Different Light Spectrum Compositions during Micropropagation of Gerbera Axillary Shoots

The experiment evaluated the influence of different light qualities and 6-benzyladenine (BA) concentration in a medium on the leaf response of multiplied Gerbera jamesonii Bolus ex Hook. f.‘Big Apple’ shoots. Three different light-emitting diode (LED) spectra—100% blue (B), 100% red (R) and red and blue mixture (7:3, RB)—were used, and a fluorescent lamp was used as a control (Fl). Concentrations of BA in Murashige and Skoog (MS) medium were 1, 2.5 and 5 µM. Leaves developed under 100% blue light had a lower frequency of stomata and a smaller area as compared with those from plants exposed to light with red in spectrum. Under 100% red light, the leaf area and the frequency of stomata increased along with growing concentration of BA in the medium. The thickest mesophyll was spotted in the cross-section of leaves exposed to the blue LED light. Leaves developed under the 100% red light had the thinnest mesophyll layers. Increasing concentration of BA in the medium resulted in enhanced leaf blade thickness. The cross-section of leaf vascular bundles was only half of that in petioles. The leaves under the LED combinations had larger vascular bundles than those under fluorescent light. The highest level of photosynthetic pigments was noticed in the leaves grown under LED R and RB lights. Our study demonstrated that 2.5 µM BA and a mixture of blue and red light provided by LED improved leaf quality during multiplication of gerbera shoots.

Hybrid rice yield response to potted-seedling machine transplanting and slow-release nitrogen fertilizer application combined with urea topdressing

Machine transplanting and the application of slow-release nitrogen (N) fertilizer (SRNF) have played vital roles in the modernization of rice production. We aimed to determine the effects of potted-seedling transplanting—a new machine-transplanting method—and SRNF on hybrid rice yields. A 2-year split-plot experiment (2016–2017) was conducted in Meishan, Sichuan province, China, using two machine-transplanting methods (potted-seedling and blanket-seedling) and three N treatments. Total green leaf area, high-effective leaf area and its rate at heading, net photosynthetic rate of flag leaves 7 days after heading, glutamate synthase (GOGAT) and glutamine synthase (GS) activity after heading, dry matter production, and N accumulation at heading and maturity increased under the potted-seedling method or 70% SRNF as a base + 30% urea application at the panicle initiation stage (SBUP). Stem diameter and number of small and of all vascular bundles at the neck–panicle node in potted-seedling plants increased as a result of increasing numbers of effective panicles, secondary branches, and spikelets. In potted-seedling plants, treatment with SBUP increased the number of large and total vascular bundles at the panicle–neck internode and the number of differentiated and surviving secondary branches and spikelets and decreased the number of ineffective tillers and degenerated secondary branches and spikelets. We conclude that the potted-seedling machine transplanting method and SRNF combined with urea topdressing can strengthen the source–sink relationship in rice, resulting in higher yields.

Xeromorphic Features of the Leaves of Liriodendron Tulipifera L. (Magnoliaceae) in the Arid Climate of Central Asia

High irradiance of a habitat in arid areas is usually associated with high temperature and dry air, which can cause water deficiency in plants. The Tulip tree (Liriodendron tulipifera) is a light-loving mesophytic species. This study showed that L. tulipifera forms shade or sun leaves depending on the light conditions. Some xeromorphic features were found in leaves of the trees in illuminated habitats. These sun leaves are smaller, denser, and thicker, with smaller epidermal cells and a thick cuticle; the spongy parenchyma consists of a larger number of rows of small cells; the cells of the columnar parenchyma are larger than the shade leaves. The sun leaf contains more total chlorophyll (by 20–30%), and the guard cells of the stomata of the sun leaf contain chloroplasts. The increased concentration of chlorophyll probably maintains the energy balance in the conditions of inhibited photosynthesis under high illumination and temperature. Decreased sizes of the sun leaf and epidermis cells, thickening of the cuticle and cell wall of epidermal cells, sunken stomata, compact mesophyll with small intercellular spaces, and multirow spongy parenchyma protect from overheating and passive loss of water and can be considered as xeromorphic features. Large numerous stomata and vascular bundles contribute to effective cooling of the surface by transpiration at high temperatures under sufficient water supply. Thus, the leaves of L. tulipifera have an ecological plasticity in relation to illumination and temperature, which contributed to the acclimation of the species to the habitat conditions in arid climates.

Physiological and Anatomical Mechanisms in Wheat to Cope with Salt Stress Induced by Seawater.

Two pot experiments were conducted in a greenhouse to examine 14C fixation and its distribution in biochemical leaf components, as well as the physiological and anatomical adaptability responses of wheat (Triticum aestivum L.) grown with seawater diluted to 0.2, 3.0, 6.0, and 12.0 dS m−1. The results showed significant reductions in chlorophyll content, 14C fixation (photosynthesis), plant height, main stem diameter, total leaf area per plant, and total dry weight at 3.0, 6.0, and 12.0 dS m−1 seawater salt stress. The 14C loss was very high at 12.0 ds m−1 after 120 h. 14C in lipids (ether extract) showed significant changes at 12.0 dS m−1 at 96 and 120 h. The findings indicated the leaf and stem anatomical feature change of wheat plants resulting from adaptation to salinity stress. A reduction in the anatomical traits of stem and leaf diameter, wall thickness, diameter of the hollow pith cavity, total number of vascular bundles, number of large and small vascular bundles, bundle length and width, thickness of phloem tissue, and diameter of the metaxylem vessel of wheat plants was found. In conclusion, salt stress induces both anatomical and physiological changes in the stem and leaf cells of wheat, as well as the tissues and organs, and these changes in turn make it possible for the plants to adapt successfully to a saline environment.

Some Characters of Different Genotypes of Brassica napus in Erbil City-Kurdistan Region-Iraq

The study was conducted at GrdaRrasha Research Field / College of Agriculture / University of Salahaddin / Erbil City – Kurdistan Region-Iraq during the winter growing season of (2014-2015), to select a genotype which has adaptation to our region&nbsp; depending on&nbsp; yield&nbsp; and quality in addition to anatomical study of the studied genotypes .For this purpose a field experiment was conducted for comparison among (12) genotypes using randomize complete block design (RCBD) with three replicates under supplemental irrigation condition. The results indicated that&nbsp; Dunckledgenoyype&nbsp; superior significantly&nbsp;&nbsp; in days from sowing to maturity ,&nbsp;&nbsp; number of pods plant-1 &nbsp;,&nbsp; Seeds Pod-1 ,&nbsp; Seed&nbsp; index&nbsp; , Seed yield (Mg ha-1) , biological yield and&nbsp; harvest index&nbsp;&nbsp; with the values of&nbsp; (166.33 days , 248.63, 25.68,&nbsp; 6.10 , 5.20, 16.20 and 0.32&nbsp; respectively,&nbsp; while&nbsp; the highest values of&nbsp; oil% and oil yield were&nbsp; recorded from Bard-1 genotype. Results also revealed the presence of large variations in numbers of vascular bundles per midribs; stem epidermal layers and thickness of cells; cortex and vascular bundles for different genotypes. The differences were observed in the vascular bundles per midrib of leaf large vascular bundle surrounded by collenchyma, except Bard-1,Rally, Rendy and Rapiferathe midribs composes of three semicircular vascular bundles. and showed variations in stem epidermal layers, were two layers as in Sultan, Bacara, and Rapifera .

Berbris aristata DC: Pharmacognostical Standardization and Phytochemical Studies of its Leaves

Berberis aristata DC. (Fam: Berberidaceae) commonly known as Daruharidra, Indian Barberry or tree turmeric. Leaves of this plant are traditionally used in the treatment of inflammation, wound healing, skin disease, menorrhagia, diarrhea, jaundice and infection of eyes etc. Micromorphology and physicochemical analysis of the leaves of B.aristata were performed as per WHO and Pharmacopoeial methods. Leaves (4.9cm × 1.8cm) are deep green on dorsal and light green on ventral side. Leaves are in tufts of 5 to 8, phyllotaxy verticillate, simple spiny, lanceolate, toothed, leathery, sessile, acuminate apex and reticulate pinnate venation. Microscopic evaluation of leaves showed biconvex midrib and thick lamina. The epidermal layers of the midrib are thick with small, less conspicuous cells and thick cuticle. The vascular system consists of three large vascular bundles; the median one is small than the two lateral bundles; the bundles are collateral and wedge shaped. Lamina is made of epidermal layer on the adaxial side with spindle shaped thick walled cells and papillate cuticle. The abaxial epidermis has squarish or rectangular epidermal cells with prominent spiny cuticular outgrowths. Powder microscopy showed the presence of cuticular papillae, anomocytic stomata and spiny outgrowth. Preliminary phytochemical screening of appropriate solvent extracts showed the presence of alkaloids, sterols, tannins, proteins and amino acids, flavonoids, terpenoids, saponin, carbohydrates and absence of glycosides and volatile and fixed oil. Microscopic analysis and other parameters were informative and provide valuable information in the identification, standardization of B.aristata leaves. Keywords: Berberis aristata, Berberidaceae, leaf, Microscopical evaluation.

English

The aim of this work was to determine the anatomical adaptations of leaves and stems of four species of Poaceae (Cynodon dactylon L. Pers., Chloris barbata SW. (Chloridoideae), Setaria verticillata L. P. Beauv., and Panicum coloratum L. (Panicoideae)) growing naturally at Al-Ha&#39;ir region near Riyadh, Saudi Arabia. Cross-sections of the leaves revealed that the epidermis cells were spherical to oval and formed one layer with a thick cuticle as well as numerous bulliform cells in a fan shape and prickles. Ground tissue (mesophyll) consists mostly of chlorenchyma cells. A large vascular bundle surrounded by two bundle sheaths, outer sheath parenchyma and inner sheath sclerenchyma were observed in C. barbata and C. dactylon, while one bundle sheath of sclerenchyma surrounds the vascular bundle in S. verticillata and P. coloratum, while one bundle sheath with chlorenchymatous cells surrounded the small vascular bundles. Our results showed that all species contained a Kranz anatomy indicative of a C4 photosynthetic pathway despite belonging to two different subfamilies, Panicoideae and Chloridoideae. Oil droplets appeared in the mesophyll tissue of P. coloratum and S. verticillata. Cross-sections of stems revealed an epidermis which consists of one layer of cells with spherical to oval shape and had a thick cuticle. Ground tissue contains strands of chlorenchyma cells followed by sclerenchyma tissue surrounding vascular bundles, thereby making a continuous cylinder. The vascular bundles were scattered in the ground tissue, with each vascular bundle surrounded by a single sclerenchymatous bundle sheath. Our results indicate that these plants were characterized by anatomical adaptations that enhance drought-tolerance capabilities, facilitating survival in arid and semi-arid regions such as Al-Ha&#39;ir and thus these plants can be used to increase vegetation cover and pasture area in dry environments. &nbsp; Key words: Anatomy, adaptations, Poaceae, Cynodon dactylon, Chloris barbata, Setaria verticillata, Panicum coloratum.

DLT/OsGRAS-32, regulating leaf width and thickness by controlling cell number in Oryza sativa

The improvement of rice leaf morphology is an important goal of rice plant breeding. Studying its molecular development mechanism will facilitate the breeding of a maximally efficient plant type. To further study the developmental mechanism of rice leaves, a dwarf broad-leaf mutant, g44, was obtained by ethyl methanesulfonate mutagenesis of the rice restorer line Jinhui10, and genetic analysis indicated that the trait was controlled by a pair of recessive nuclear gene. The locus was fine mapped on chromosome 6 with 16-kb physical distance. Sequencing revealed that an A-T base substitution occurred in the mutant, resulting in the early termination of LOC_Os06g03710/DLT translation in g44 and yielding only one residual peptide containing 558 amino acids. The phenotypic and sequencing results of the complementary transgenic plants and the allelic mutant g44-1 further confirmed this result. Mutant plants grown under field conditions showed dwarfing, a leaf colour of dark green, leaf widening, and grain enlargement. Paraffin section and cryosection analysis showed that the increase in the number of large vascular bundles and small vascular bundles and the increase in the spacing between adjacent small vascular bundles were the main reasons for the broadening of mutant leaves. In addition, the increase in thickness of the mesophyll cell layer may be the main reason for the increase in leaf colour darkness and net photosynthetic rate. The qPCR results preliminarily predicted that the increase in the number of mutant cells was caused by an enhanced cell division ability, and the DLT/G44 gene was proposed to participate in the regulation of cell division by suppressing the expression of cyclin-related genes.

Structural Characterization of Mint (Mentha x villosa Huds) Stem and Leaf

Aims: The objective of this study was to identify the structural characteristics of the shoots of Mentha x villosa Huds and also, identify the main structures responsible for the production of active principles.&#x0D; Methodology: The analyzes were performed with stems and leaves from adult and healthy plants, which presented a uniform morphological pattern. The materials selected for the anatomical analyzes were fixed in FAA for 24 hours and after this period conditioned in 70% alcohol. Cross-sections and paradermic sections were manually made with a cutting blade. For sections analysis, 1% sodium hypochlorite was used for discoloration and safranine 10% dye for tissue staining.&#x0D; Results: The leaf of Mentha x villosa Huds presents asymmetric mesophyll, formed by palisade and lacunar parenchyma, and uniseriate epidermis. The diacytic stomata are located on the abaxial surface of the leaves with different sizes, all having a substomatal chamber. On both sides of leaves, glandular trichomes were observed in great quantity. The leaf midrib is formed by a large vascular bundle, with xylem facing the adaxial surface and phloem facing the abaxial surface. The stem presents uniseriate epidermis and below it can be found one or two layers of colenchyma. The vascular bundle consists of four main xylem points, and externally to it is found the phloem, which gives the quadrangular shape to the stem. Mentha x villosa Huds has characteristics that are common to aromatic species of the Lamiaceae family, which makes its characterization and differentiation difficult, as for example, its secretory structures which do not have taxonomic importance for differentiation on this species, since they are similar in other species of the same family.&#x0D; Conclusion: However, Mentha x villosa has a larger number of cell layers in the lacunar parenchyma, which is an important characteristic for the differentiation of species.

Cloning of a COBL gene determining brittleness in diploid wheat using a MapRseq approach

Plant tissue brittleness is related to cellular structure and lodging. MED0031 is a mutant identified previously from ethyl methane sulfonate treatment of diploid wheat accession TA2726, showing brittleness in both stem and leaf. In microscopic and histological observations, the mutant was found to have less large vascular bundles per unit area, a thinner sclerenchyma cell wall, and a broader parenchyma, compared with the wild type. The mutated gene, TmBr1, was mapped to a 0.056 cM interval on chromosome 5Am. This gene was cloned using a MapRseq approach that searched the candidate gene through combination of the prior target gene mapping information with SNP calling and discovery of differentially expressed genes from RNA_seq data of the wild type and a BC3F2 bulk showing the mutant phenotype. TmBr1 encodes a COBL protein and a nonsense mutation within the region coding for the conserved COBRA domain caused premature translation termination. Introduction of TmBr1 to Arabidopsis AtCOBL4 mutant rescued the phenotype, demonstrating their functional conservation. Apart from the effect on cellulose content, the TmBr1 mutation might modulate synthesis of noncellulosic polysaccharide pectin as well. Application of the MapRseq approach to isolation of genes present in recombination cold spots and complicated genomes was discussed.

Multiple areas investigation reveals the genes related to vascular bundles in rice

BackgroundThe vascular bundle in the panicle neck is a crucial trait in rice (Oryza sativa) production that differs between the indica and japonica subspecies. However, the effect of indica/japonica genetic background on the vascular bundles remains unknown.ResultsA series of recombinant inbred lines (RILs) derived from a cross between japonica and indica were planted in three areas. High-throughput sequencing was conducted to determine the indica pedigree percentage and for quantitative trait locus (QTL) analysis. The indica pedigree affected the number of large vascular bundles (LVBs), but not the number of small vascular bundles (SVBs). QTL analysis identified a locus (qLVB9) that was pleiotropic for both LVBs and SVBs in all three areas, and qLVB9 appeared synonymous with DENSE AND ERECT PANICLE 1 (DEP1). Using CRISPR/Cas9 gene editing and gene overexpression technology, we confirmed that the truncated dep1 allele increased the number of LVBs, and resulted in LVBs more closely associated to the indica pedigree. RNA sequencing showed that the truncated dep1 allele downregulated the AP2-like gene family. The double mutant for the DEP1 and AP2-like genes (OsAP2–39) showed decreased endogenous abscisic acid (ABA) level and insensitivity to exogenous ABA treatment, confirming that both DEP1 and OsAP2–39 are involved in the ABA response mechanism.ConclusionsThe present study showed the qLVB9/DEP1 affects LVBs, and involved in ABA signaling via regulating the AP2-like gene family. These results offer new insights into the function of qLVB9/DEP1 in rice.