Callus Cells Research Articles

Simultaneous but spatially different regulation of non-photosynthetic callus formation and photosynthetic root development after shoot removal

ABSTRACTPlants coordinate plastid differentiation and cellular differentiation during tissue development. Recently, we reported a mechanism of chloroplast development and photosynthetic improvement in Arabidopsis roots after shoot removal. Shoot removal induces the expression of WOUND INDUCED DEDIFFERENTIATION (WIND) transcription factors at the wound site, which activates type-B ARABIDOPSIS RESPONSE REGULATOR (ARR)-mediated cytokinin signaling in roots. The type-B ARR signaling upregulates chloroplast-related transcription factors along with photosynthesis-associated genes, thereby inducing chloroplast development in detached roots. However, at the wound site, WINDs promote the development of non-green callus cells in a type-B ARR-dependent manner. Thus, in shoot-removed roots, WIND-mediated cytokinin signaling has spatially distinct roles: it represses chloroplast development at the wound site while activating the development in adjacent regions. Because WINDs are strong inducers of cell dedifferentiation, spatial differences in their expression levels between the wound site and other areas may determine the fate of chloroplast development.

Production of Schisandrin A and Schisandrin B from Callus and Suspension Cell Cultures of Schisandra chinensis

For establishing the fermentation system of synthetic schizandrin A and schizandrin B, culture conditions of the Schisandra chinensis callus and the suspension cell were studied in this paper. The friable calluses of Schisandra chinensis (Turcz.) Baill. were induced from hypocotyls in Murashige-Skoog (MS) solidified medium supplemented with hormone 6-benzylaminopurine (6-BA) and 2,4-Dichlorophenoxyacetic butyl acetate (2,4-D) in different concentrations, and suspension cells initiated from friable callus were cultured in MS liquid medium with various concentrations and combinations of 6-BA, 2,4-D and kinetin (KT). The optimal culture condition for callus inducement was found to be MS solidified medium with 6-BA 1.0 mg/l and 2,4-D 0.3 mg/l and the optimal condition for suspension cells was MS liquid medium with 6-BA 1.0 mg/l, 2,4-D 0.2 mg/l and KT 0.5 mg/l. UPLC/Q-TOF-MS method was used for accurate identification of schisandrin A and schisandrin B in the seeds, callus and suspension cells of S. chinensis. And HPLC analytical method was used successfully for identification and quantification of these metabolites in cultures of S. chinensis. As a result, schisandrin A was obtained 0.251 mg/g, 0.118 mg/g and 0.115 mg/g from seeds, callus and suspension cells and schisandrin B was 0.142 mg/g, 0.086 mg/g and 0.05 mg/g from seeds, callus and suspension cells, respectively. Our datas indicate that callus and suspension cells had capability as seeds of S. chinensis for schisandrin A and schisandrin B synthesizing and can be used as potential sources of these biologically active lignans.

Establishment of callus and cell suspension cultures of Eysenhardtia polystachya (Ortega) and fungistatic activity of their extracts

Eysenhardtia polystachya (Fabaceae) is a valuable medicinal plant from Mexico. There have been no cell culture studies of this plant to produce secondary metabolites. The aim of this work was to establish callus and cell suspension cultures of E. polystachya (Ortega) and to evaluate the content of phenols, total flavonoids, and fungicidal activity against Sclerotium cepivorum and Rhizoctonia solani from extracts of wild plant and cell cultures. An efficient protocol for callus induction and cell cultures was established. The maximum percentage of explants inducing callus (100 and 98%) was obtained using 1-naphthaleneacetic acid (8.28μM) plus kinetin (0.41μM) or picloram (4.14μM) plus kinetin (0.41μM), respectively. Only the cell suspension cultures from callus with picloram plus kinetin grew appropriately and the maximum dry biomass accumulation (14gL−1) occurred at 12days of culture. The leaves from wild plants yielded larger amounts of total phenols (155.17mggallic acid equivalentsg−1 dry weight) and total flavonoids (124.3mgquercetin equivalentsg−1 dry weight) compared to cell suspension cultures, which exhibited total phenols amounts of 73.98mggallic acid equivalentsg−1 dry weight and total flavonoids of 16.29mgquercetin equivalentsg−1 dry weight. The fungicide Cercobin® inhibited 100% the S. cepivorum mycelial growth, while 80.0 and 73.0% inhibition was achieved with the ethyl acetate fraction of the dichloromethane extracts from E. polystachya sapwood and heartwood, respectively. However, cell suspension cultures showed only 39% inhibition of S. cepivorum mycelial growth with methanol extracts. The maximum percentage inhibition of R. solani (66.0%) occurred using the hexane fraction of methanolic extracts from cell suspension cultures; however, Cercobin® presented only 33.0% growth inhibition. Extracts of E. polystachya cell suspension cultures can be used as a biotechnological option against phytopathogenic fungi.

Cadmium impact, accumulation and detection in poplar callus cells.

Effect of cadmium cations and their interaction with silicon cations was determined in poplar calli and expressed as changes in callus growth, cell viability and cadmium cation accumulation. Cell viability throughout culture versus cadmium cation accumulation in cells is discussed. At the same time, the study sought appropriate methods for cadmium cation detection in callus cells and also in experiments with low plant material (e.g. protoplasts). Cadmium cations were determined by atomic absorption spectroscopy and using fluorescence microscopy with a specific cadmium cation fluorescent dye. The detection of cadmium cations in callus cells by the latter method appears suitable because the callus cells are surrounded by primary cell walls without auto-fluorescence and these values fit well with atomic absorption spectroscopy quantification. However, the visualisation method has some limits discussed below.

Establishment of Callus Induction and Cell Suspension Cultures of Dendrathema Indicum var. Aromaticum a Scented Chrysanthemum

Dendranthema indicum var. aromaticum is an important aroma plant in genus Dendrathema, and the establishment of callus cultures and cell suspension cultures is the basement of further protoplast fusion studies, which make it possible to breed new fragrant chrysanthemum. In this study, the effects of different plant growth regulating substances in different concentrations on callus induction were investigated with stem segments, leaves, petioles as explants. The results showed that the optimal explants were lower stem segments according to the percentage of callus formation, callus hardness, growth potential and shoot differentiation. The optimal induction mediums were MS supplemented with 1.0 mg．l-12.4 D and 0.2 mg．l-1 6-BA. The cell suspension culture system was established by using the subculture calli. The results showed that the suitable inoculum size was 2g and the suitable cell suspension culture medium was MS supplemented with 0.2 mg．l-1 6-BA and 0.5 mg．l-1 2,4-D. The time course of cell growth showed that the greatest cell fresh weight appeared on day 14 and the highest cell viability on day 3.

Callus Induction from Various Organs of Dragon Fruit, Apple and Tomato on some Mediums.

Dragon fruit (Hylocereus spp.), apple (Malus sylvestris Mill.) and tomato (Solanum lycopersicum L.) are high potential sources of antioxidant compounds such as phenolics. The compounds have the capability of protecting cells and tissues against free radicals. Secondary metabolite produced by callus cell culture from plant organs also acts as a source of antioxidants. This study aimed to determine the optimal ratio of sucrose and 2,4-D in Murashige and Skoog (MS) medium for callus induction from different plant organ explants. With all of characteristic, callus can be used further for the development of natural cell regeneration agent. This study was conducted using analytical technique. Suitable explants were obtained. They were developed in various concentrations of combination between MS medium and 2,4-D. Callus growth, including their weight and surface was then measured and analyzed by using one-way analysis of variance (ANOVA). Callus was able to grow from its explants in 5-7 days after induction process. They were clear in color and had friable texture. The highest value of fresh weight of dragon fruit callus was obtained through MS supplemented with 1 μL L-1 2,4-D and 30 g sucrose. However, apple and tomato callus induction and growth maintenance reached optimal medium on MS supplemented with 30 g sucrose and 2 μL L-1 2,4-D. Callus of apple, dragon fruit and tomato was maintained upon MS supplemented with 30-40 g sucrose and 1-2 μL L-1 2,4-D for optimum induction and growth. The optimization of growth medium will give advantages for further development of natural cell regeneration agent.

A Two-Step Model for de Novo Activation of WUSCHEL during Plant Shoot Regeneration.

Plant cells are totipotent and competent to regenerate from differentiated organs. It has been known for six decades that cytokinin-rich medium induces shoot regeneration from callus cells. However, the underlying molecular mechanism remains elusive. The homeodomain transcription factor WUSCHEL (WUS) is essential for de novo establishment of the shoot stem cell niche in Arabidopsis thaliana We found that WUS-positive (WUS+) cells mark the shoot progenitor region during regeneration. A cytokinin-rich environment initially promotes the removal of the repressive histone mark H3K27me3 at the WUS locus in a cell cycle-dependent manner. Subsequently, the B-type ARABIDOPSIS RESPONSE REGULATORs (ARRs) ARR1, ARR2, ARR10, and ARR12, which function as transcriptional activators in the cytokinin signaling pathway, spatially activate WUS expression through binding with microRNA165/6-targeted HD-ZIP III transcription factors. Thus, our results provide important insights into the molecular framework for cytokinin-directed shoot regeneration and reveal a two-step mechanism for de novo activation of WUS.

Relationship observed between salinity-tolerant callus cell lines and anatomical structure of Line 2 (Oryza sativa L.) indica under salinity stress

Abstract Rice is an important staple crop but is highly susceptible to abiotic stress. Polysaccharides (β-glucan) and BG serve as crucial functions in regulating plant development and growth, especially in responding to abiotic stress. Callus responds to BG and NaCl signals through various chemical and biochemical processes. However, no prior study on BG signals specific to in vitro plants or callus cultures of rice has been conducted. Therefore, the response of rice callus to BG pre-treatment was examined. The exogenous addition of BG to the stress media increased the salt tolerance of callus significantly though enhancing antioxidant activity. However, Na accumulation and Na/K ratio decreased significantly in callus throughout the experimental 3-month period. The results identified that Line 2 exposed to a salinity condition from callus, exhibits good growth characteristics and high biochemical activities. Furthermore, it had the better anatomical structure, chlorophyll content and net photosynthetic rate compared to Line 2, which was derived from control. BG as antioxidants, scavenge reactive oxygen species to mitigate possible injury on biomembranes under salt stress. The application of BG may induce an adaptive response in callus by stimulating antioxidant enzyme activities and showing the relationship between salt-tolerant callus cell lines and the histological structure of Line 2 shoot and root.

Genomic characterization of miR156 and SQUAMOSA promoter binding protein-like genes in sweet orange (Citrus sinensis)

miR156, as one of the first discovered and most conserved microRNAs (miRNAs) in plants, was known to play versatile roles in plants, through regulation of the target SBP-box genes, a plant-specific transcription factor family. In this study, four MIR156 and 15 SQUAMOSA promoter binding protein-like (SPL) genes were retrieved from Citrus sinensis genome. According to the phylogenetic grouping with plant SPLs, synteny analysis with Arabidopsis SPLs, characterization of exon–intron structure and motif organization, the CsSPL genes were clustered into two major groups, and one major group was further divided into seven subgroups. The possible function of CsSPLs was inferred based on their likely orthologous relationship to SPLs in Arabidopsis. The precursor of csi-miR156a was isolated and overexpressed in citrus callus. The transformed callus cells were found to over-accumulate amyloids, resulting in increased starch content. Among the nine CsSPLs targeted by csi-miR156a/b, only CsSPL2 and CsSPL14 showed downregulated transcript level in miR156 overexpressed lines, suggesting the involvement of ‘miR156-CsSPL’ module in starch accumulation. In this study, genomic analysis of miR156 and SPL gene family of C. sinensis was conducted, and preliminary function of miR156-SPL was validated in citrus callus lines.

Nuclear genome stability in long-term cultivated callus lines of Fagopyrum tataricum (L.) Gaertn.

Long-term cultivated Fagopyrum tataricum (L.) Gaertn. (Tartary buckwheat) morphogenic and non-morphogenic callus lines are interesting systems for gaining a better understanding of the mechanisms that are responsible for the genetic stability and instability of a plant tissue culture. In this work, we used histological sections and transmission electron microscopy to identify and describe the morphology of the nuclei of all of the analysed callus lines. We demonstrated that the embryogenic callus cells had prominent round nuclei that did not contain heterochromatin clumps in contrast to the non-morphogenic callus lines, in which we found nuclei that had multiple lobes. Flow cytometry analysis revealed significant differences in the relative DNA content between the analysed calli. All of the analysed morphogenic callus lines had peaks from 2C to 8C as compared to the non-morphogenic callus lines, whose peaks did not reflect any regular DNA content and exceeded 8C and 16C for the line 6p1 and 16C and 32C for the callus line 10p2A. The results showed that non-morphogenic calli are of an aneuploid nature. The TUNEL test enabled us to visualise the nuclei that had DNA fragmentation in both the morphogenic and non-morphogenic lines. We revealed significantly higher frequencies of positively labelled nuclei in the non-morphogenic lines than in the morphogenic lines. In the case of the morphogenic lines, the highest observed frequency of TUNEL-positive nuclei was 7.7% for lines 2–3. In the non-morphogenic calli, the highest level of DNA damage (68.5%) was revealed in line 6p1. These results clearly indicate greater genome stability in the morphogenic lines.

Response of the callus cells of fir (Abies nordmanniana) to in vitro heavy metal stress

Abstract The aim of the presented research was to investigate the effect of three heavy metals - lead, cadmium and copper - on the callus cells of Abies nordmanniana. The toxicity degree and toxicity effect of the selected heavy metals was determined on the embryonic level. On the basis of the spectrometric analyses as well as macroscopic and microscopic observations, this research referred to the accumulation of heavy metals in tissues, assuming that this mechanism is related to the acquisition of tolerance by cells exposed to this type of abiotic stress. Moreover, the effect of the genotype of fir on the cell defence, that is, the induction of tolerance, was analysed. Understanding of the issues related to the heavy metal resistance of plant genotypes in future may contribute to the selection of genotypes of individuals that are more resistant to stress factors, particularly in the multi-directional and rational forest management. The results showed that lead (20 mg l-1), which proved to be the most toxic amongst the three examined heavy metals, has the most severe negative effects on the tissue of fir trees. Copper (20 mg l-1) was accumulated for a long time in the cells of fir trees, and it was not degraded or excreted outside the tissues even after three weeks of in vitro culture. Of the three tested genotypes, G14 had the greatest tendency to accumulate each of the examined metals, that is, it appeared to be the least tolerant genotype.

Indirect Morphogenesis and Regenerative Ability of Tissues of Rosa Damascena Mill

Obtaining of morphogenic callus of Lan variety of ROSA and formation of the regenerant plants from callus tissues is a necessary issue nowadays. For the research we used Rosa Damascena Mill. variety of Ukrainian selection Lan. For obtaining of the callus tissue we used sterile leaf plates and parts of stems with axillary buds cultured in nutrient media with the addition of the various groups of cytokinins and auxins. Plant tissue was stained with hematoxylin by Heidenhain and acetofuxin. Plant material was recorded for 24 hours by Chamberlain's method. We have obtained the following results. Firstly, on the medium, the beginning of the callusogenesis of aromatic rose's explants was recorded on parts of leaf plates after 7-9 days, and for microstems – 10-14 days of cultivation. Later callus was subcultured on the nutrient media, supplemented with growth regulators – BAP, NAA, IAA and TDZ. Visually, the first signs of the morphogenesis of callus culture were fixed on the 2nd day of cultivation. The differentiation of cells and the formation of callus tissue of morphogenic structures is largely dependent on the concentration and ratio of growth regulators that under relevant competences of cells stimulate processes hemogenesis. Analysis of experimental data shows that usage of only BAP in the MS medium did not lead to the initiation of the morphogenic callus formation. Secondly, under the influence of hormonal stimuli callus tissues actively formed on the basal parts of shoots of explants and on the surfaces of leaves contacting to the culture medium that contained the required components for the cell proliferation. Thus under these conditions the organogenesis occurs de novo, the first metameres, with absence of the necessary environment, biochemical and spatial disorder carry out the signs of teratogenesis. As a result of conducted studies we have determined that in Lan variety callus begins to form twice as actively in the parts of the leaf blades than in stem parts. Morphogenic zones in the system of callus cells of Rosa Damascena Mill. are represented as meristemoids. Primary bodies have limited growth; however they perform an important function: actively take part in photosynthesis, form hormones and growth regulators that are required for normal development.

Rubia tinctorum L. Hücre Kültürlerinde Tuz Stresi ve Inokülasyon Oranlarının Etkileri

In this study, salt stress was implemented to callus and cell suspension cultures of Rubia tinctorum L. at 100 mM and 200 mM concentrations and the effects on fresh and dry weights (g), relative dry weight ratios, and alizarin and purpurin contents (mg/g dry weight) of biomass were determined. Due to an increase in salt concentrations, biomass obtained from callus and cell suspension cultures were decreased. In callus cultures, due to the low viability and proliferation rate of the callus cells, the biomass showed no significant increase. Alizarin and purpurin contents decreased as the salt concentrations in callus cultures increased, but amounts of these compounds increased in cell suspension cultures. Inoculation ratios were also found effective on fresh and dry weights, and alizarin and purpurin contents of the samples tested. 1:2 inoculation ratio caused higher alizarin and purpurin contents in cell suspension cultures, but biomass amounts were found higher at 1:4 inoculation ratio. The highest alizarin ( 3.183 mg/g) and purpurin ( 1.153 mg/g) contents were detected in the sample that had 1:2 inoculation ratios and was obtained from the medium at 200 mM NaCl concentration.

BDNF regulates the expression and secretion of VEGF from osteoblasts via the TrkB/ERK1/2 signaling pathway during fracture healing.

Brain‑derived neurotrophic factor (BDNF), a member of the neurotropic family, is expressed in osteoblast‑like cells of a fracture callus, however, its role in fracture healing remains to be fully elucidated. Osteoblasts isolated from Sprague Dawley rats were stimulated by BDNF in a dose‑ and time‑dependent manner. Immunoblotting and immunofluorescence was used to detect the expression and distribution of targeted proteins. The concentration of vascular endothelial growth factor (VEGF) released in medium was determined using an ELISA. PD98059 and K252a were used to investigate the signaling pathways that may be involved. The present study demonstrated that BDNF was involved in fracture repair by controlling the expression and secretion of VEGF from osteoblasts, which predominantly drives angiogenesis during fracture healing. Tropomyosin‑related kinase B (TrkB), the specific receptor of BDNF, was shown to be expressed at high levels in the osteoblasts. Following BDNF stimulation, TrkB and extracellular signal‑regulated kinase1/2 (ERK1/2) were rapidly activated. The inhibition of TrkB by K252a decreased the expression and secretion of VEGF, and suppressed the phosphorylation level of ERK1/2. PD98059, an antagonist of ERK1/2, elicited the same effects on VEGF from the BDNF‑stimulated osteoblasts, however, it did not affect the phosphorylation of TrkB. In conclusion, during fracture healing, BDNF was found to stimulate the expression and secretion of VEGF from osteoblasts via the TrkB/ERK1/2 signaling pathway.

Growth pattern of friable calluses from leaves of Capsicum annuum var. annuum cv. Iberaba Jalapeño

The genus Capsicum belongs to the Solanaceae botanical family and is notable for the production of secondary metabolites of medicinal and economical importance. In vitro methods have been successfully utilized for the large scale production of plant secondary metabolites. The objective of this study was to establish a protocol for callus induction from leaves, nodal and internodal segments of the cultivar C. annuum var. annuum cv. Iberaba Jalapeno, and to determine the growth pattern of the calluses, aiming at the identification of the deceleration phase, when the callus cells must be subcultured for the establishment of cell suspensions and the production of secondary metabolites. The explants were inoculated into a medium supplemented with BA and 2,4-D in factorial combination. Percentage of callus induction and the explant area covered by callus cells (ACCC) were evaluated. The procedures that resulted in higher proliferation of callus cells were repeated in order to determine the growth curve of the calluses. The highest callus induction percentage and ACCC were observed with the combination of 2.22 µM BA + 18.10 µM 2,4-D for leaf and internodal explants and 2.22 µM BA + 9.05 µM 2,4-D for nodal explants. The calluses produced were friable and whitish, and their growth pattern followed a sigmoid shape. The deceleration phase started on the 31st day of cultivation for leaf explants, on the 26th for internodal explants, and on the 29th day for nodal explants.

Plant Explants Grown on Medium Supplemented with Fe3O4 Nanoparticles Have a Significant Increase in Embryogenesis

Development of nanotechnology leads to the increasing release of nanoparticles in the environment that results in accumulation of different NPs in living organisms including plants. This can lead to serious changes in plant cultures which leads to genotoxicity. The aims of the present study were to detect if iron oxide NPs pass through the flax cell wall, to compare callus morphology, and to estimate the genotoxicity in Linum usitatissimum L. callus cultures induced by different concentrations of Fe3O4 nanoparticles. Two parallel experiments were performed: experiment A, where flax explants were grown on medium supplemented with 0.5 mg/l, 1 mg/l, and 1.5 mg/l Fe3O4 NPs for callus culture obtaining, and experiment B, where calluses obtained from basal MS medium were transported into medium supplemented with concentrations of NPs identical to experiment A. Obtained results demonstrate similarly in both experiments that 25 nm Fe3O4 NPs pass into callus cells and induce low toxicity level in the callus cultures. Nevertheless, calluses from experiment A showed 100% embryogenesis in comparison with experiment B where 100% rhizogenesis was noticed. It could be associated with different stress levels and adaptation time for explants and calluses that were transported into medium with Fe3O4 NPs supplementation.

The calcium-dependent protein kinase gene VaCPK29 is involved in grapevine responses to heat and osmotic stresses

Ca2+-dependent protein kinases (CDPKs or CPKs) are essential primary sensors of Ca2+ in plants and are known to play important roles in plant abiotic and biotic stress responses. Vitis amurensis is a wild grapevine species with a high level of cold and disease resistance. It has previously been shown that transcription of 10 CDPK genes of V. amurensis was elevated under salt, desiccation, high mannitol, cold, and heat stress conditions. Expression of VaCPK29 was induced under high and low temperatures, water deficit, and high mannitol stress in plant cuttings of V. amurensis. The present study revealed that the callus cell cultures of V. amurensis and soil-grown plants of Arabidopsis thaliana overexpressing VaCPK29 exhibited higher tolerance to heat and high mannitol stress in comparison with the control transformed with the empty vector. Cold, salt, and drought stress tolerance of the transgenic V. amurensis calli and A. thaliana plants was comparable to that of the controls. The stress-responsive genes AtDREB1A, AtDREB2A, AtRD29A, AtRD29B, and AtABF3 were up-regulated in the VaCPK29-overexpressing A. thaliana plants under heat stress. Taken together, the data indicate that the VaCPK29 gene may act as a positive regulator in the grapevine response to heat and osmotic stresses.

The histology of minigrafting of Persian walnut trees cv. chandler

Compared to other techniques of propagation, grafting is the most successful and feasible technique for asexual propagation of walnut plants. There is little information about graft union formation in walnut. Therefore, the objective of this study was to evaluate histological events during graft union formation in Juglans regia L. cv. Chandler scions when minigrafted on the one-year-old seedlings. Cross and longitudinal sections of the graft union were taken for examining different stages of grafting process after 1, 14, 30, 60, 120, 180, 420 and 540 days of minigrafting. One day after grafting, brown necrotic layers were observed at the cut edges. The first callus cells were initiated from cambium layer of rootstock 14 days after grafting but there was weak connection between two parts. New vascular connections between rootstock and scion were observed 30 days after grafting . Vascular connections were increased in central parts of the graft union 60 days after grafting. In mid-summer (180 days after grafting), necrotic layer was almost disappeared in the central longitudinal sections but they were increased especially in the bark, callus and top parts of the graft union due to high temperature and low humidity. In 420 days after grafting, two parts were strongly connected by xylem vessels, but necrotic layer was still remained and observed in some parts. In 540 day after grafting which was coincided with the end of second growing season, two parts were tightly connected to each other and necrotic layer disappeared in most of cross and longitudinal sections.

Spatial Distribution of Selected Chemical Cell Wall Components in the Embryogenic Callus of Brachypodium distachyon.

Brachypodium distachyon L. Beauv. (Brachypodium) is a species that has become an excellent model system for gaining a better understanding of various areas of grass biology and improving plant breeding. Although there are some studies of an in vitro Brachypodium culture including somatic embryogenesis, detailed knowledge of the composition of the main cell wall components in the embryogenic callus in this species is missing. Therefore, using the immunocytochemical approach, we targeted 17 different antigens of which five were against the arabinogalactan proteins (AGP), three were against extensins, six recognised pectic epitopes and two recognised hemicelluloses. These studies were complemented by histological and scanning electron microscopy (SEM) analyses. We revealed that the characteristic cell wall components of Brachypodium embryogenic calli are AGP epitopes that are recognised by the JIM16 and LM2 antibodies, an extensin epitope that is recognised by the JIM11 antibody and a pectic epitopes that is recognised by the LM6 antibody. Furthermore, we demonstrated that AGPs and pectins are the components of the extracellular matrix network in Brachypodium embryogenic culture. Additionally, SEM analysis demonstrated the presence of an extracellular matrix on the surface of the calli cells. In conclusion, the chemical compositions of the cell walls and ECMSN of Brachypodium callus show spatial differences that correlate with the embryogenic character of the cells. Thus, the distribution of pectins, AGPs and hemicelluloses can be used as molecular markers of embryogenic cells. The presented data extends the knowledge about the chemical composition of the embryogenic callus cells of Brachypodium.

Micropipette extraction-based PCR amplification of mRNAs in single friable tomato callus cells

Micropipette extraction-based PCR amplification of mRNAs in single friable tomato callus cells