scholarly journals Genomewide analysis of small RNAs in nonembryogenic and embryogenic tissues of citrus: microRNA-and siRNA-mediated transcript cleavage involved in somatic embryogenesis

2015 ◽  
Vol 13 (3) ◽  
pp. 383-394 ◽  
Author(s):  
Xiao-Meng Wu ◽  
Shu-Jun Kou ◽  
Yuan-Long Liu ◽  
Yan-Ni Fang ◽  
Qiang Xu ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Small Rnas ◽  
Transcript Cleavage ◽  
Embryogenic Tissues

scholarly journals Bioreactors in coffee micropropagation

2006 ◽  
Vol 18 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Hervé Etienne ◽  
E Dechamp ◽  
D Barry-Etienne ◽  
Bernóit Bertrand
Keyword(s):  
Somatic Embryogenesis ◽  
Scaling Up ◽  
Coffea Canephora ◽  
Root Tip ◽  
Temporary Immersion ◽  
Axis Elongation ◽  
Cotyledon Expansion ◽  
Tip Formation ◽  
Embryogenic Tissues ◽  
Rapid Mass

In coffee, bioreactors are the most promising way for scaling-up micropropagation processes, particularly somatic embryogenesis. The availability of an efficient somatic embryogenesis process would allow the rapid mass production of heterozygous materials such as selected Coffea canephora clones and F1 Arabica hybrid varieties. For the last fifteen years, bioreactors (mechanically or pneumatically agitated bioreactors, temporary immersion bioreactors) have mostly been used on coffee to optimize the mass regeneration of somatic embryos from embryogenic tissues. This review presents the main results, obtained with several bioreactor models, concerning the different steps of the micropropagation process : i) the multiplication of embryogenic tissues, ii) the somatic embryo mass regeneration and iii) the production of pre-germinated embryos and plantlets in bioreactors. The literature shows that scaling-up can be successful, since very efficient embryo production has been achieved for both C. arabica and C. canephora. Moreover, it was proven that the pre-germinated coffee embryos - i.e. embryonic axis elongation (10-12 mm), root tip formation, cotyledon expansion and greening - obtained in temporary immersion bioreactors were photoautotrophic and able to regenerate vigorous plantlets after sowing under nursery conditions. The feasibility to apply the bioreactor technology in an industrial micropropagation procedure is also discussed in the particular socio-economic context of coffee growing.

The Role of Small RNAs in Plant Somatic Embryogenesis

2019 ◽  
pp. 311-338
Author(s):  
Brenda A. López-Ruiz ◽  
Vasti T. Juárez-González ◽  
Eduardo Luján-Soto ◽  
Tzvetanka D. Dinkova
Keyword(s):  
Somatic Embryogenesis ◽  
Small Rnas

scholarly journals THE EFFECT OF PICLORAM AND LIGHT ON SOMATIC EMBRYOGENESIS REGENERATION OF PINEAPPLE

2012 ◽  
Vol 13 (2) ◽  
pp. 43 ◽  
Author(s):  
Ika Roostika ◽  
Nurul Khumaida ◽  
Ika Mariska ◽  
Gustaaf Adolf Wattimena
Keyword(s):  
Somatic Embryogenesis ◽  
Butyric Acid ◽  
Somatic Embryos ◽  
Callus Formation ◽  
Light Condition ◽  
Cell Polarization ◽  
Mass Propagation ◽  
Benzyl Adenine ◽  
Indole Butyric Acid ◽  
Embryogenic Tissues

<p>Smooth Cayenne is the largest pineapple type cultivated in Indonesia, but its vegetative planting materials for mass propagation are limited. Somatic embryogenesis is a potential method to be applied. The aim of this study was to investigate the somatic embryogenesis regeneration under the effect of picloram and light. Callus formation was induced by picloram (21, 41 and 62 μM) added with 9 μM thidiazuron. The calli were transferred onto MS or Bac medium  enriched with N-organic compounds with or without addition of 21 μM picloram under dark or light condition. The compact calli were subcultured onto MS medium supplemented with 4.65 μM kinetin, while the friable calli were  transferred onto BIG medium (modified MS + 1.1 μM benzyl adenine + 0.9 μM indole butyric acid + 0.09 μM giberelic acid) or B medium (MS + 0.018 mM benzyl adenine). The results showed that the events of somatic embryogenesis were started from cell polarization, asymmetrical division, proembryo formation as  embryogenic tissues and friable embryogenic tissues, and embryo development. The best treatment for callus induction was 21 μM picloram. The addition of 21 μM picloram on N-organic enriched medium and the use of light condition  proliferated embryogenic calli. The N-organic enriched Bac medium and light condition yielded the highest number of mature somatic embryos (17 embryos per<br />explant in 2 months). The B medium was better than BIG medium to develop  somatic embryos from friable embryogenic tissues. The somatic embryogenesis method presented is potential for pineapple mass propagation and artificial seed<br />production.</p><p>Abstrak Bahasa Indonesia</p><p>Smooth Cayenne merupakan kultivar nenas yang banyak dibudidayakan di  Indonesia, namun ketersediaan benih untuk perbanyakan massal masih terbatas. Embriogenesis somatikadalah metode yang potensial untuk produksi bibit secara massal. Tujuan penelitian adalah untuk mempelajari pengaruh pikloram dan pencahayaan terhadap regenerasi embriogenesis somatik nenas. Kalus diinduksi menggunakan pikloram (21, 41, dan 62 μM) dan penambahan thidiazuron 9 μM. Selanjutnya, kalus dipindahkan ke media MS atau Bac yang diperkaya dengan<br />senyawa N-organik dengan atau tanpa penambahan pikloram 21 μM dalam kondisi gelap atau dengan pencahayaan. Kalus kompak disubkultur pada media MS yang mengandung kinetin 4,65 μM, sedangkan kalus remah dipindahkan ke media BIG (MS modifikasi + bensil adenin 1.1 μM + indole butyric acid 0,9 μM + giberelic acid 0,09 μM) atau media B (MS + bensil adenin 0,018 μM). Hasil penelitian  menunjukkan bahwa tahapan embriogenesis somatik diawali dengan polarisasi sel, pembelahan asimetris, pembentukan proembrio sebagai jaringan embriogenik dan<br />jaringan embriogenik remah, serta perkembangan embrio. Perlakuan terbaik untuk induksi kalus adalah pikloram 21 μM. Penambahan pikloram 21 μM pada media yang diperkaya dengan senyawa N-organik mampu meningkatkan jumlah kalus<br />embriogenik. Media Bac yang diperkaya senyawa N-organik dan kondisi pencahayaan menghasilkan jumlah embrio somatik dewasa terbanyak (17 embrio per eksplan dalam 2 bulan). Media B lebih baik daripada media BIG untuk regenerasi embrio somatik dari jaringan embriogenik remah. Metode embriogenesis somatik yang dihasilkan dari penelitian ini berpotensi diterapkan untuk<br />perbanyakan massal dan produksi benih nenas.</p>

Improving initiation, genotype capture, and family representation in somatic embryogenesis of Pinus radiata by a combination of zygotic embryo maturity, media, and explant preparation

2009 ◽  
Vol 39 (8) ◽  
pp. 1566-1574 ◽  
Author(s):  
Cathy L. Hargreaves ◽  
Cathie B. Reeves ◽  
Jens I. Find ◽  
Keiko Gough ◽  
Puthiyaparambil Josekutty ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Pinus Radiata ◽  
Zygotic Embryo ◽  
Embryogenic Tissue ◽  
Zygotic Embryos ◽  
Embryogenic Tissues ◽  
Preparation Techniques ◽  
Embryo Maturity ◽  
Collection Time ◽  
Excised Embryos

The principal aim of this investigation was to improve somatic embryogenesis initiation and to enhance representation of families and genotypes within those families of Pinus radiata D. Don. A total of 19 open-pollinated seed families, many with unrelated and weakly related parents, were tested. Optimum stage of cone maturity for initiation success was tested by five collections made at 1 week intervals, spanning the developmental period from pro-embryo to cotyledonary embryos. Two media were compared; embryo-development media (EDM6) and a modified Litvay medium (Glitz). Two zygotic embryo explant-preparation techniques were tested; embryos with retained megagametophytes and excised embryos. Proliferating embryogenic tissues were obtained from all four treatments (2850 explants per treatment, 570 per collection time) for the 19 families. The best initiation rates were achieved with a combination of Glitz medium with excised zygotic embryos, with 55% of explants from all collections and all families combined giving rise to proliferating embryogenic tissue. At the optimal collection time for each of the families, this treatment gave a range of 47%–97% initiation success with an average of 70% per family.

scholarly journals Post-transcriptional regulation of several biological processes involved in latex production in Hevea brasiliensis

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8932 ◽  
Author(s):  
Julie Leclercq ◽  
Shuangyang Wu ◽  
Benoît Farinas ◽  
Stéphanie Pointet ◽  
Bénédicte Favreau ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Small Rna ◽  
Small Rnas ◽  
Transcriptional Silencing ◽  
Gene Families ◽  
Transcriptional Level ◽  
Rubber Biosynthesis ◽  
Transcript Cleavage ◽  
Post Transcriptional Regulation ◽  
Latex Production

Background Small RNAs modulate plant gene expression at both the transcriptional and post-transcriptional level, mostly through the induction of either targeted DNA methylation or transcript cleavage, respectively. Small RNA networks are involved in specific plant developmental processes, in signaling pathways triggered by various abiotic stresses and in interactions between the plant and viral and non-viral pathogens. They are also involved in silencing maintenance of transposable elements and endogenous viral elements. Alteration in small RNA production in response to various environmental stresses can affect all the above-mentioned processes. In rubber trees, changes observed in small RNA populations in response to trees affected by tapping panel dryness, in comparison to healthy ones, suggest a shift from a transcriptional to a post-transcriptional regulatory pathway. This is the first attempt to characterise small RNAs involved in post-transcriptional silencing and their target transcripts in Hevea. Methods Genes producing microRNAs (MIR genes) and loci producing trans-activated small interfering RNA (ta-siRNA) were identified in the clone PB 260 re-sequenced genome. Degradome libraries were constructed with a pool of total RNA from six different Hevea tissues in stressed and non-stressed plants. The analysis of cleaved RNA data, associated with genomics and transcriptomics data, led to the identification of transcripts that are affected by 20–22 nt small RNA-mediated post-transcriptional regulation. A detailed analysis was carried out on gene families related to latex production and in response to growth regulators. Results Compared to other tissues, latex cells had a higher proportion of transcript cleavage activity mediated by miRNAs and ta-siRNAs. Post-transcriptional regulation was also observed at each step of the natural rubber biosynthesis pathway. Among the genes involved in the miRNA biogenesis pathway, our analyses showed that all of them are expressed in latex. Using phylogenetic analyses, we show that both the Argonaute and Dicer-like gene families recently underwent expansion. Overall, our study underlines the fact that important biological pathways, including hormonal signalling and rubber biosynthesis, are subject to post-transcriptional silencing in laticifers.

scholarly journals Interactions in the Agrobacterium-soybean system and capability of some Brazilian soybean cultivars to produce somatic embryos

2000 ◽  
Vol 23 (1) ◽  
pp. 217-220 ◽  
Author(s):  
Antonio Orlando Di Mauro ◽  
José Carlos Martins de Nóbrega ◽  
Sonia Marli Z. Di Mauro ◽  
Glenn Burton Collins
Keyword(s):  
Somatic Embryogenesis ◽  
Agrobacterium Tumefaciens ◽  
Somatic Embryos ◽  
Significant Interaction ◽  
Virulent Strain ◽  
Soybean Cultivars ◽  
Immature Cotyledons ◽  
Petri Dishes ◽  
Agrobacterium Tumefaciens C58 ◽  
Embryogenic Tissues

Twenty-five Brazilian soybean cultivars were studied for susceptibility to four strains of Agrobacterium tumefaciens (C58, Ach5, Bo542 and A281) and for their ability to produce somatic embryos. Twelve plants of each cultivar were inoculated in a greenhouse at 4-6 weeks of age, using 12 inoculation sites per plant. The number of galls formed on plants were counted 8-10 weeks after inoculation. To study ability to produce somatic embryos, immature cotyledons, 4-6 mm in length, were plated onto N10 medium for induction of somatic embryogenesis, using four Petri dishes with 20 cotyledons for each cultivar. The embryogenic tissues were transferred onto new N10 medium six times at 15-day intervals and the number of somatic embryos per cultivar determined. Significant interaction between soybean cultivars and A. tumefaciens strains was observed; the most virulent strain was A281. The opine type apparently had no effect on strain virulence, and the most embryogenic cultivars were IAS-5, Cristalina, FT-Cometa, IAC-7 and OC-3.

scholarly journals Computational Identification and Comparative Analysis of Conserved miRNAs and Their Putative Target Genes in the Juglans regia and J. microcarpa Genomes

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1330
Author(s):  
Le Wang ◽  
Tingting Zhu ◽  
Karin R. Deal ◽  
Jan Dvorak ◽  
Ming-Cheng Luo
Keyword(s):  
Small Rnas ◽  
Target Genes ◽  
Juglans Regia ◽  
Protein Coding ◽  
Functional Annotations ◽  
Translation Repression ◽  
Transcript Cleavage ◽  
English Walnut ◽  
Post Transcriptional Regulation ◽  
Homoeologous Chromosomes

MicroRNAs (miRNAs) are important factors for the post-transcriptional regulation of protein-coding genes in plants and animals. They are discovered either by sequencing small RNAs or computationally. We employed a sequence-homology-based computational approach to identify conserved miRNAs and their target genes in Persian (English) walnut, Juglans regia, and its North American wild relative, J. microcarpa. A total of 119 miRNA precursors (pre-miRNAs) were detected in the J. regia genome and 121 in the J. microcarpa genome and miRNA target genes were predicted and their functional annotations were performed in both genomes. In the J. regia genome, 325 different genes were targets; 87.08% were regulated by transcript cleavage and 12.92% by translation repression. In the J. microcarpa genome, 316 different genes were targets; 88.92% were regulated by transcript cleavage and 11.08% were regulated by translation repression. Totals of 1.3% and 2.0% of all resistance gene analogues (RGA) and 2.7% and 2.6% of all transcription factors (TFs) were regulated by miRNAs in the J. regia and J. microcarpa genomes, respectively. Juglans genomes evolved by a whole genome duplication (WGD) and consist of eight pairs of fractionated homoeologous chromosomes. Within each pair, the chromosome that has more genes with greater average transcription also harbors more pre-miRNAs and more target genes than its homoeologue. While only minor differences were detected in pre-miRNAs between the J. regia and J. microcarpa genomes, about one-third of the pre-miRNA loci were not conserved between homoeologous chromosome within each genome. Pre-miRNA and their corresponding target genes showed a tendency to be collocated within a subgenome.

scholarly journals Physiological and Structural Aspects of In Vitro Somatic Embryogenesis in Abies alba Mill

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1210
Author(s):  
Terezia Salaj ◽  
Katarina Klubicová ◽  
Bart Panis ◽  
Rony Swennen ◽  
Jan Salaj
Keyword(s):  
Somatic Embryogenesis ◽  
Cell Lines ◽  
Somatic Embryos ◽  
Abies Alba ◽  
Embryogenic Tissue ◽  
Zygotic Embryos ◽  
Peg 4000 ◽  
Initiation Frequency ◽  
Embryogenic Tissues

Initiation of somatic embryogenesis from immature zygotic embryos, long-term maintenance of embryogenic tissue in vitro or by cryopreservation, as well as maturation, of somatic embryos of Abies alba Mill. are reported in this study. For the initiation of embryogenic tissues, a DCR medium containing different types of cytokinins (1 mg.L−1) were tested. During three consecutive years, 61 cell lines were initiated out of 1308 explants, with initiation frequencies ranging between 0.83 and 13.33%. The type of cytokinin had no profound effect on the initiation frequency within one given year. Microscopic observations revealed presence of bipolar somatic embryos in all initiated embryogenic tissues. Besides the typical bipolar somatic embryos, huge polyembryonal complexes, as well as “twin” embryos, were observed. Maturation of somatic embryos occurred on a DCR medium supplemented by abscisic acid (10 mg.L−1), polyethylene glycol (PEG-4000, 7.5%) and 3% maltose. The maturation capacity was cell-line dependent. All of the four tested cell lines produced cotyledonary somatic embryos, though at different quantities, of 16 to 252 per g of fresh weight. After germination, seedlings developed, but their further growth soon stopped after the formation of a resting bud. Altogether, seven cell lines were cryopreserved, using the slow-freezing technique. After rewarming, all tested cell lines showed regrowth rates between 81.8 and 100%.

scholarly journals Tolerance of Norway spruce (Picea abies [L.] Karst.) embryogenic tissue to penicillin, carbapenem and aminoglycoside antibiotics

2009 ◽  
Vol 55 (No. 4) ◽  
pp. 156-161 ◽  
Author(s):  
J. Malá ◽  
D. Pavingerová ◽  
H. Cvrčková ◽  
J. Bříza ◽  
J. Dostál ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Picea Abies ◽  
Norway Spruce ◽  
Aminoglycoside Antibiotic ◽  
Embryogenic Tissue ◽  
Transformation Protocol ◽  
Selective Media ◽  
Accelerated Growth ◽  
Embryogenic Tissues ◽  
Carbapenem Antibiotic

Somatic embryogenesis is conveniently utilized for the preparation of Norway spruce (<I>Picea abies</I> [L.] Karst.) transgenic clones by means of <I>Agrobacterium</I>. The establishment of successful transformation protocol requires to determine the tolerance of growing embryogenic tissue to antibiotics in culture and selective media. In 5 Norway spruce lines (genotypes) differences in the tolerance of embryogenic tissues to penicillin antibiotics (amoxicillin, carbenicillin, and ticarcillin), carbapenem antibiotic (meropenem) used for the <I>Agrobacterium</I> growth prevention, and aminoglycoside antibiotic (kanamycin) used in selective media were determined. Of the penicillin derivatives, amoxicillin was optimally tolerated in all lines and, in addition, its highest concentration accelerated growth in more rapidly growing lines. Ticarcillin was similarly tolerated but no growth acceleration was observed in any line. As regards carbenicillin, only the lowest concentration was observed to be well tolerated by all lines whereas all concentrations of meropenem were well tolerated in all lines except for slowly growing line 28, the growth of which was retarded by the concentration of 20 mg/l. The aminoglycoside antibiotic kanamycin was well tolerated by the embryonic tissue of all lines in the concentration of 10 mg/l and less in the concentration of 25 mg/l. The concentrations of 50 mg/l and 100 mg/l appeared as intolerable in all lines. Toxicity of kanamycin manifested at first in the browning and later in the growth cessation of embryogenic tissue.

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