In vitro regeneration of two Populus hybrid clones. The role of pectin domains in cell processes underlying shoot organogenesis induction

In vitro regeneration by shoot organogenesis and-or somatic embryogenesis is accomplished by culturing the explants on a nutrient medium supplemented with phytohormones. Auxins in general, and 2,4-D in particular, have been shown to induce somatic embryogenesis whereas shoot regeneration is stimulated by cytokinins. In studying the morphoregulatory role of thidiazuron (TDZ) - a substituted urea with cytokinin-like activity - we found that it induces a high frequency of both organogenesis and somatic embryogenesis depending upon the plant species. For instance, whole seedlings of peanut developed somatic embryos and those of bean and pea produced shoots in response to culture on TDZ (1-40 μM)-supplemented media. In cultured explants of geranium, the use of TDZ (0.2-1 μM) effectively replaced the requirement of 2,4-D or BAP and IAA for obtaining somatic embryos. The frequency of regeneration was two to ten times higher than that achieved with auxin-cytokinin combinations. While no direct evidence is currently available to establish a relationship between TDZ and endogenous phytohormones, our results suggest that it may act by establishing endogenously the auxin:cytokinin ratio permissive of induction and expression of morphogenically competent cells.

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Natural Variation in Plant Pluripotency and Regeneration

Plants ◽

10.3390/plants9101261 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1261

Author(s):

Robin Lardon ◽

Danny Geelen

Keyword(s):

De Novo ◽

Shoot Organogenesis ◽

In Vitro Regeneration ◽

Relative Role ◽

Root Explants ◽

Experimental Systems ◽

Complex Process ◽

Insight Into ◽

Molecular Framework

Plant regeneration is essential for survival upon wounding and is, hence, considered to be a strong natural selective trait. The capacity of plant tissues to regenerate in vitro, however, varies substantially between and within species and depends on the applied incubation conditions. Insight into the genetic factors underlying this variation may help to improve numerous biotechnological applications that exploit in vitro regeneration. Here, we review the state of the art on the molecular framework of de novo shoot organogenesis from root explants in Arabidopsis, which is a complex process controlled by multiple quantitative trait loci of various effect sizes. Two types of factors are distinguished that contribute to natural regenerative variation: master regulators that are conserved in all experimental systems (e.g., WUSCHEL and related homeobox genes) and conditional regulators whose relative role depends on the explant and the incubation settings. We further elaborate on epigenetic variation and protocol variables that likely contribute to differential explant responsivity within species and conclude that in vitro shoot organogenesis occurs at the intersection between (epi) genetics, endogenous hormone levels, and environmental influences.

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Effects of Variations in Hormonal Treatments Upon In vitro Regeneration Potential in Embryo Explants of Arenga pinnata

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v17n5.2120 ◽

2021 ◽

Vol 17 (5) ◽

pp. 495-503

Author(s):

Shamsiah Abdullah ◽

Siti Nurain Roslan

Keyword(s):

Acetic Acid ◽

In Vitro Regeneration ◽

Hormonal Treatment ◽

Height Increment ◽

Regeneration Potential ◽

In Vitro Method ◽

Indole 3 Acetic Acid ◽

Hormonal Treatments

One of the challenges related to propagation of Arenga pinnata is its lengthy period of seed dormancy. In this study, in vitro regeneration was carried out to determine the effect of hormonal treatment on the embryo explant of Arenga pinnata. Embryos were surface sterilized and cultured into different media supplemented with various hormones concentrations and combinations. Each treatment contained of Kinetin (KN) hormone (1.0, 2.0, and 3.0 mg/l) and in combination with indole-3-acetic acid (IAA) of 0.1, 0.2, 0.3 mg/l. The height of plumule and length of radical was observed and recorded. Treatment 8 (3 mg/ml KN + 0.1 mg/ml IAA) showed 59.09% in plumule height increment while treatment 4 (1 mg/ml KN + 0.3 mg/ml IAA) showed the highest radical increments with 93.62%. The knowledge gained in this study consequently helps us to better understand the role of KN and IAA in the in vitro regeneration protocol. Since in vitro method able to produce higher number of in vitro seedlings at one time, it is important to establish the in vitro regeneration protocol for this plant.

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Isolation and characterization of calcifying bacteria from “living rocks”: a possible carbon sink

10.5194/egusphere-egu21-8538 ◽

2021 ◽

Author(s):

Maddalena del Gallo ◽

Amedeo Mignini ◽

Giulio Moretti ◽

Marika Pellegrini ◽

Paola Cacchio

Keyword(s):

Calcium Carbonate ◽

Carbon Sink ◽

In Vitro Regeneration ◽

Scientific Basis ◽

16S Rrna Analysis ◽

Environmental Threats ◽

Isolation And Characterization ◽

Definition Of

CO2 emissions triggered by anthropogenic and natural activities contribute to climate change, one of the current environmental threats of public and scientific concern. At present, microbially-induced biomineralization of CO2 by calcium carbonate (CaCO3) is one of the highly topical study subjects as carbon stabilization process. In the present study we focused our attention on the calcifying bacteria of &#8220;living rocks&#8221;. The origin of these concretions, composed by a silicate skeleton of quartz and feldspars, merged by massive carbonate concrete, has so far been recognized as abiotic. Within this study we investigated the role of calcifying bacteria in their formation of these concretions and we isolated and characterized the species with CaCO3 precipitation abilities. Concretions were sampled in Romania (Trovant) and Italy (Sibari and Rome). Samples were first analyzed for their culturable microflora (i.e. isolation, CaCO3 precipitation capability and molecular characterization). Then, in vitro regeneration tests were carried out to confirm the contribution of bacteria in the formation of these erratic masses. Moreover, natural samples and bioliths regenerated in vitro were (i) observed and analyzed by scanning electron microscopy (SEM-EDS) and (ii) characterized at molecular level by DNA extraction and 16S rRNA analysis (V3-V4 regions). By isolating and characterizing the culturable microflora, we obtained 19 calcifying isolates, with different morphological, bacteriological and mineral precipitation properties. These evidences have given a first relevant contribution for the definition of the biotic role to the formation of these concretions. These evidences were confirmed by the efficient in vitro regeneration and SEM-EDS analysis. The molecular identification of the isolates and the comparison of the data obtained from the Illumina sequencing with those present in the literature, allowed us to hypothesize the genera that most likely contributed to the formation of these concretions. The results obtained provide a good scientific basis for further studies, which should be directed towards the use of isolates in studies of environmental and socio-economic relevance. Several studies demonstrate that microbially mediated biomineralization has the potential to capture and sequester carbon. Calcium carbonate, is a stable pool of carbon and is an effective sealant to prevent CO2 release back into the atmosphere.

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MICROFILAMENTS AND CELL LOCOMOTION

The Journal of Cell Biology ◽

10.1083/jcb.49.3.595 ◽

1971 ◽

Vol 49 (3) ◽

pp. 595-613 ◽

Cited By ~ 256

Author(s):

Brian S. Spooner ◽

Kenneth M. Yamada ◽

Norman K. Wessells

Keyword(s):

Protein Synthesis ◽

Plasma Membrane ◽

Cytochalasin B ◽

Cell Movement ◽

Leading Edge ◽

Complete Recovery ◽

Cell Locomotion ◽

Cell Processes

The role of microfilaments in generating cell locomotion has been investigated in glial cells migrating in vitro. Such cells are found to contain two types of microfilament systems: First, a sheath of 50–70-A in diameter filaments is present in the cytoplasm at the base of the cells, just inside the plasma membrane, and in cell processes. Second, a network of 50-A in diameter filaments is found just beneath the plasma membrane at the leading edge (undulating membrane locomotory organelle) and along the sides of the cell. The drug, cytochalasin B, causes a rapid cessation of migration and a disruption of the microfilament network. Other organelles, including the microfilament sheath and microtubules, are unaltered by the drug, and protein synthesis is not inhibited. Removal of cytochalasin results in complete recovery of migratory capabilities, even in the absence of virtually all protein synthesis. Colchicine, at levels sufficient to disrupt all microtubules, has no effect on undulating membrane activity, on net cell movement, or on microfilament integrity. The microfilament network is, therefore, indispensable for locomotion.

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In-vitro Regeneration from Direct and Indirect Organogenesis of Crescentia alata Kunth an Important Multipurpose Medicinal Tree

European Journal of Medicinal Plants ◽

10.9734/ejmp/2021/v32i330381 ◽

2021 ◽

pp. 48-58

Author(s):

R. Abinaya

Keyword(s):

Shoot Organogenesis ◽

In Vitro Regeneration ◽

Basal Medium ◽

Direct Organogenesis ◽

Ms Medium ◽

Indirect Organogenesis ◽

Medicinal Tree ◽

Short Period ◽

In Vitro Clonal Propagation

In this present work, an in-vitro regeneration protocol for Crescentia alata (C. alata) was developed using various explants on Murashige and Skoog (MS) medium augmented with different concentrations and combinations of plant growth regulators (PGRs) for direct and indirect regeneration. The direct organogenesis was established from nodes and internodes on MS medium supplemented with cytokinins and auxins. The indirect organogenesis via callus phase was obtained from leaf, nodes and internodes on MS medium supplemented with different concentrations of PGRs. The high frequency shoot organogenesis were achieved directly from nodal explants were cultured on MS medium supplemented with 3.0 mg/L BAP+0.5 mg/L KIN +1.0 mg/L NAA. Indirect organogenesis callogenic frequency was optimized at the concentration of MS medium containing 1.0 mg/L BAP + 5.0 mg/L IAA. The callus was obtained from all the explants were used, among these explants internodal explants gave best result on MS medium supplemented with different concentrations of cytokinins and auxins for indirect organogenesis experiment. Indirect organogenesis the highest number of shoot regeneration was obtained in MS Basal Medium with 4.0 mg/L BAP + 0.5 mg/L KIN + 2.0 mg/L NAA from internodal explants. For root formation the regenerative shoots which were sub cultured on MS medium containing different ratios of auxins. The rooted plantlets were transferred successfully to the pots containing sterilized soil and were successfully hardened at greenhouse condition for 20 days then exposed to the natural environment. This is the first successful micropropagation report of an efficient and rapid in-vitro clonal propagation protocol for C. alata by direct and indirect shoot organogenesis through various explants, which can be employed for conservation of this important medicinal tree species as well as the utilization of an biologically important active biomolecules. This protocol can be very useful to obtain plants from various explants, without the requirement of meristematic regions, enabling the obtainment of a higher number of plants in short period.

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Integrating the Roles for Cytokinin and Auxin in De Novo Shoot Organogenesis: From Hormone Uptake to Signaling Outputs

International Journal of Molecular Sciences ◽

10.3390/ijms22168554 ◽

2021 ◽

Vol 22 (16) ◽

pp. 8554

Author(s):

Martin Raspor ◽

Václav Motyka ◽

Abdul Rasheed Kaleri ◽

Slavica Ninković ◽

Ljiljana Tubić ◽

...

Keyword(s):

Shoot Regeneration ◽

De Novo ◽

Shoot Organogenesis ◽

In Vitro Regeneration ◽

Genetic Regulation ◽

Auxin Signaling ◽

Plant Tissues ◽

Cultivated Plant ◽

The Media

De novo shoot organogenesis (DNSO) is a procedure commonly used for the in vitro regeneration of shoots from a variety of plant tissues. Shoot regeneration occurs on nutrient media supplemented with the plant hormones cytokinin (CK) and auxin, which play essential roles in this process, and genes involved in their signaling cascades act as master regulators of the different phases of shoot regeneration. In the last 20 years, the genetic regulation of DNSO has been characterized in detail. However, as of today, the CK and auxin signaling events associated with shoot regeneration are often interpreted as a consequence of these hormones simply being present in the regeneration media, whereas the roles for their prior uptake and transport into the cultivated plant tissues are generally overlooked. Additionally, sucrose, commonly added to the regeneration media as a carbon source, plays a signaling role and has been recently shown to interact with CK and auxin and to affect the efficiency of shoot regeneration. In this review, we provide an integrative interpretation of the roles for CK and auxin in the process of DNSO, adding emphasis on their uptake from the regeneration media and their interaction with sucrose present in the media to their complex signaling outputs that mediate shoot regeneration.

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In vitro regeneration of groundnut: Changes in antioxidative enzymes and histological studies

Journal of Agricultural Sciences Belgrade ◽

10.2298/jas1401063t ◽

2014 ◽

Vol 59 (1) ◽

pp. 63-73 ◽

Cited By ~ 1

Author(s):

Rohini Trivedi

Keyword(s):

Antioxidative Enzymes ◽

Stress Responses ◽

Shoot Organogenesis ◽

In Vitro Regeneration ◽

Stage Iv ◽

Dichlorophenoxyacetic Acid ◽

In Vitro Morphogenesis ◽

Histological Studies ◽

2,4 Dichlorophenoxyacetic Acid

Reactive oxygen species (ROS) produced during stress responses are implicated in a number of cellular responses including morphogenesis. The present study was undertaken to study the changes in antioxidative enzymes during in vitro morphogenesis of groundnut from de-embryonated cotyledon explants cultured on Murashige and Skoog?s medium supplemented with 5.0 mg l-1 benzyl-adenine and 2.0 mg l-1 2,4-dichlorophenoxyacetic acid. During the early in vitro ontogenic stages of groundnut, the activity of peroxidase (POD) and polyphenol oxidase (PPO) increased from stage 0 (0 day) to stage II (14 days) and decreased during stage III (25 days) and stage IV (45 days). The activity of superoxide dismutase (SOD) showed an inverse trend. The results could be correlated with the acquisition of competence, de-differentiation, division and induction which occurred during shoot organogenesis. Histological studies also showed that the mode of in vitro morphogenesis from the groundnut explants was via shoot organogenesis. In light of the above study, it could be concluded that the change in activity of the antioxidative enzymes studied could be used as a marker to characterize the mode of plant regeneration.

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An efficient in vitro regeneration system of fieldpea (Pisum sativum L.) via. shoot organogenesis

Journal of Plant Biochemistry and Biotechnology ◽

10.1007/s13562-013-0200-3 ◽

2013 ◽

Vol 23 (2) ◽

pp. 184-189 ◽

Cited By ~ 5

Author(s):

Alok Das ◽

Sumit Kumar ◽

P. Nandeesha ◽

Indu Singh Yadav ◽

Jyoti Saini ◽

...

Keyword(s):

Pisum Sativum ◽

Shoot Organogenesis ◽

In Vitro Regeneration ◽

Regeneration System ◽

Pisum Sativum L

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Early Sucrose Degradation and the Dominant Sucrose Cleavage Pattern Influence Lycoris sprengeri Bulblet Regeneration In Vitro

International Journal of Molecular Sciences ◽

10.3390/ijms222111890 ◽

2021 ◽

Vol 22 (21) ◽

pp. 11890

Author(s):

Ziming Ren ◽

Yunchen Xu ◽

Xuesi Lvy ◽

Dong Zhang ◽

Cong Gao ◽

...

Keyword(s):

In Vitro Regeneration ◽

Expression Patterns ◽

Soluble Sugar ◽

Cleavage Pattern ◽

Regeneration System ◽

Total Soluble Sugar ◽

Bulb Yield ◽

Sucrose Cleavage

Bulblet formation and development determine the quantitative and qualitative traits, respectively, of bulb yield for most flowering bulbs. For Lycoris species, however, the underlying molecular mechanism remains elusive. Here, clonal bulblets of Lycoris sprengeri (Ls) derived from the same probulb were used as explants to establish efficient and inefficient in vitro regeneration systems by adjusting the 6-benzyladenine (BA) concentrations in media. BA application did not change the biological processes among groups but led to earlier decreases in sucrose and total soluble sugar (TSS) contents. Correlation analyses showed that the BA treatments changed the interaction between carbohydrate and endogenous hormone contents during bulblet regeneration. We found that two sucrose degradation enzyme-related genes, cell wall invertase (CWIN) and sucrose synthase, exhibited exactly opposite expression patterns during the competence stage. In addition, the regeneration system that obtained more bulblets showed significantly higher expression of LsCWIN2 than those that obtained fewer bulblets. Our data demonstrate the essential role of BA in accelerating sucrose degradation and the selection of a dominant sucrose cleavage pattern at the competence stage of in vitro bulblet regeneration. We propose that a relatively active CWIN-catalyzed pathway at the competence stage might promote bulblet regeneration, thus influencing bulb yield.

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