scholarly journals Activation of plant LTR-retrotransposons under in vitro culture stress

2021 ◽  
Vol 18 (1-2) ◽  
pp. 58-69
Author(s):  
I. I. Konvalyuk ◽  
O. M. Bublyk ◽  
I. O. Andreev
Keyword(s):  
In Vitro Culture ◽  
Biotic Stress ◽  
Specific Binding ◽  
Regulatory Elements ◽  
Stress Conditions ◽  
Raw Material ◽  
Plant Genome ◽  
Ltr Retrotransposons ◽  
Abiotic And Biotic Stress

Retrotransposons make up a significant part of plant genome and are probably the most dynamic part of it, so they play a significant role in the generation of genetic variation. In particular, their activation can lead to structural reorganization of genome and changes in genome size, the emergence of novel genetic and phenotypic variants, as well as changes in gene expression, thus providing the raw material for adaptation and evolution. This review summarizes literature data on the activation of LTR-retrotransposons of the superfamilies Ty1/Copia and Ty3/Gypsy during in vitro culture and under various abiotic and biotic stress conditions. Their structure, classification, and significance for the organization and functioning of plant genome are reviewed. The main mechanisms of activation of LTR-retrotransposons under stress conditions are explored, including changes in DNA methylation and interaction of stress-induced transcription factors with retrotransposon promoters due to the presence of specific binding sites and other regulatory elements. The review also discusses consequences of activation of retrotransposons and control of their activity by self-inactivation mechanisms and the epigenetic regulation of genome.Keywords: retrotransposons, Ty1/Copia, Ty3/Gypsy, in vitro culture, abiotic and biotic stress.

scholarly journals Role of ethylene and the APETALA 2/ethylene response factor superfamily in rice under various abiotic and biotic stress conditions

2017 ◽  
Vol 134 ◽  
pp. 33-44 ◽  
Author(s):  
Rambod Abiri ◽  
Noor Azmi Shaharuddin ◽  
Mahmood Maziah ◽  
Zetty Norhana Balia Yusof ◽  
Narges Atabaki ◽  
...  
Keyword(s):  
Biotic Stress ◽  
Stress Conditions ◽  
Ethylene Response Factor ◽  
Response Factor ◽  
Abiotic And Biotic Stress ◽  
Ethylene Response ◽  
Apetala 2

Use of Polyglycolic Acid Unwoven and Woven Fibers for Tendon Engineering In Vitro

2005 ◽  
Vol 288-289 ◽  
pp. 7-10 ◽  
Author(s):  
Xian Wei ◽  
P.H. Zhang ◽  
W.Z. Wang ◽  
Z.Q. Tan ◽  
De Jun Cao ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Mechanical Test ◽  
Biomechanical Properties ◽  
Polyglycolic Acid ◽  
Raw Material ◽  
Control Group ◽  
Proper Form ◽  
Median Diameter ◽  
Observation Period

Objective: To compare biocompatibility, degradation, and mechanical properties of polyglycolic acid (PGA) unwoven and woven fibers as scaffolding materials for tendon engineering in vitro. Methods: Three kinds of PGA fibers were included in this study. PGA raw material (Purac Co, Holland) was spun into single PGA filaments that were further twisted into woven fibers (PGA- 1). PGA filaments (Nantong Holycon, China) were twisted into woven fibers (PGA-2) as well. PGA-1 and PGA-2 served as experimental groups 1 and 2, while unwoven PGA fibers (Albany Co, USA) served as control group. Three types of PGA fibers were made into cord-like scaffolds that mimic tendon shape and compared with each other for biocompatibility, degradation and biomechanical properties. Avian tenocytes were isolated from digital flexor tendon and expanded in vitro. Cells of the second passage were seeded onto the PGA scaffolds. In the first 2 weeks, the cell- PGA constructs were in vitro cultured without tension and observed for cell adhesion and matrix production. The constructs were then cultured under dynamic loading in a bioreactor for another 2 weeks followed by gross and histological examinations. Results: PGA unwoven fibers have the median diameter of 10µm, while PGA-1 and PGA-2 fibers have the median diameters of 200µm and 60µm, respectively. Microscopy showed that tenocytes adhered well to all three types of PGA fibers in the first 10 days and produced abundant matrices. However, cells showed poor viability on PGA-2 fibers after 10 days, yet good viability on the other two PGA fibers over 2 weeks of observation period. H&E staining showed that there were viable cells and abundant matrices in the control and PGA-1 groups, but not in PGA-2 group after 4 weeks of in vitro culture. Additionally, PGA unwoven fibers degraded faster than woven fibers (PGA-1 and -2). Interestingly, the PGAtenocyte constructs formed tendon-like tissue after 4 weeks of in vitro culture grossly and histologically. Furthermore, mechanical test demonstrated that both PGA woven fibers had much higher tensile strength than unwoven fibers. Conclusion: Different PGA fibers have different biocompatibility with seeded tenocytes. PGA woven fibers could bear more intense mechanical loading and degrade slower than unwoven fibers, which is essential for in vitro generation of tendon tissue. Thus PGA woven fibers might serve as a proper form of scaffolding material for in vitro tendon engineering in a bioreactor.

scholarly journals Morpho-agronomic characteristics of valerian (Valeriana officinalis L.) derived from in-vitro culture

2021 ◽  
Vol 306 ◽  
pp. 01001
Author(s):  
Siti Fatimah Syahid ◽  
Hera Nurhayati ◽  
Budi Hartoyo
Keyword(s):  
Pharmaceutical Industry ◽  
In Vitro Culture ◽  
Morphological Characteristics ◽  
Culture Technique ◽  
Raw Material ◽  
Valeriana Officinalis ◽  
Agronomic Characteristics ◽  
Randomized Design ◽  
Medicinal Crops

Valeriana officinalis belongs to the Valerianaceae family, is a well-known herb and medicinal plant. Plant roots are commonly used as medicine by the pharmaceutical industry. Observation on morpho-agronomic characteristics of valerian propagated in vitro is needed to determine their morphological characteristics and production in the field. The study aimed to observe the morphological characteristics of valerian derived from in vitro culture. The experiment was conducted at the Indonesian Spices and Medicinal Crops Research Institute (ISMCRI) Bogor, arranged in a Completely Randomized Design with three replications. Each replication consisted of ten individual plants. Valerian plantlets from in vitro culture were acclimatized in the greenhouse and planted in media composed of a mixture of soil, compost, and husk. Afterward, 3 months old valerian was then transferred into a polybag. The plants were harvested at 9 and 12 months after planting (MAP). Valerian plantlets from in vitro propagation were successfully acclimatized in the greenhouse. Furthermore, the morphological characteristics of the plant were similar to the parents. The yield was significantly higher at 12 MAP than 9 MAP. The tissue culture technique was prospective for valerian propagation to support rapid plant material provision for seeds or raw material for the pharmaceutical industry.

cis- and trans-acting regulatory elements of the yeast URA3 promoter

1990 ◽  
Vol 10 (10) ◽  
pp. 5257-5270
Author(s):  
A Roy ◽  
F Exinger ◽  
R Losson
Keyword(s):  
Specific Binding ◽  
Point Mutations ◽  
Regulatory Elements ◽  
Cis Acting ◽  
Cell Extracts ◽  
Dnase I Footprinting ◽  
Pair Sequence ◽  
Dyad Symmetry

Expression of the yeast pyrimidine biosynthetic gene, URA3, is induced three- to fivefold in response to uracil starvation, and this regulation is mediated by the transcriptional activator PPR1 (pyrimidine pathway regulator 1). In this study, we have analyzed the regulatory elements of the URA3 promoter by DNase I footprinting, using partially purified yeast cell extracts, by deletion mutagenesis, and by 5'-end mapping of RNA transcripts. Two DNA-binding activities have been detected, and at least four distinct cis-acting regions have been identified. A region rich in poly(dA-dT) serves as an upstream promoter element necessary for the basal level of URA3 expression. A 16-base-pair sequence with dyad symmetry acts acts as a uracil-controlled upstream activating site (UASURA) and shows a specific binding only with cell extracts from strains overproducing PPR1. This in vitro binding does not require dihydroorotic acid, the physiological inducer of URA3. The TATA region appears to be composed of two functionally distinct (constitutive and regulatory) elements. Two G + A-rich regions surrounding this TATA box bind an unidentified factor called GA-binding factor. The 5' copy, GA1, is involved in PPR1 induction and overlaps the constitutive TATA region. The 3' region, GA2, is necessary for maximal expression. Neither of these GA sequences acts as a UAS in a CYC1-lacZ context. The promoters of the unlinked but coordinately regulated URA1 and URA4 genes contain highly conserved copies of the UASURA sequence, which prompted us to investigate the effects of many point mutations within this UASURA sequence on PPR1-dependent binding. In this way, we have identified the most important residues of this binding site and found that a nonsymmetrical change of these bases is sufficient to prevent the specific binding and to suppress the UASURA activity in vivo. In addition, we showed that UASURA contains a constitutive activating element which can stimulate transcription from a heterologous promoter independently of dihydroorotic acid and PPR1.

scholarly journals Methodologies for In Vitro Cloning of Small RNAs and Application for Plant Genome(s)

2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
Eric J. Devor ◽  
Lingyan Huang ◽  
Abdusattor Abdukarimov ◽  
Ibrokhim Y. Abdurakhmonov
Keyword(s):  
Small Rna ◽  
High Throughput Sequencing ◽  
Rna World ◽  
Regulatory Elements ◽  
Plant Genome ◽  
Transcriptional Gene Silencing ◽  
Small Interfering Rnas ◽  
Sequencing Technologies ◽  
Post Transcriptional Gene Silencing

The “RNA revolution” that started at the end of the 20th century with the discovery of post-transcriptional gene silencing and its mechanism via RNA interference (RNAi) placed tiny 21-24 nucleotide long noncoding RNAs (ncRNAs) in the forefront of biology as one of the most important regulatory elements in a host of physiologic processes. The discovery of new classes of ncRNAs including endogenous small interfering RNAs, microRNAs, and PIWI-interacting RNAs is a hallmark in the understanding of RNA-dependent gene regulation. New generation high-throughput sequencing technologies further accelerated the studies of this “tiny world” and provided their global characterization and validation in many biological systems with sequenced genomes. Nevertheless, for the many “yet-unsequenced” plant genomes, the discovery of small RNA world requires in vitro cloning from purified cellular RNAs. Thus, reproducible methods for in vitro small RNA cloning are of paramount importance and will remain so into the foreseeable future. In this paper, we present a description of existing small RNA cloning methods as well as next-generation sequencing methods that have accelerated this research along with a description of the application of one in vitro cloning method in an initial small RNA survey in the “still unsequenced” allotetraploid cotton genome.

Physiological Characterisation of Salt-resistant Rice (Oryza sativa) Somaclones

1999 ◽  
Vol 47 (6) ◽  
pp. 835 ◽  
Author(s):  
Stanley Lutts ◽  
Jules Bouharmont ◽  
Jean-Marie Kinet
Keyword(s):  
Oryza Sativa ◽  
In Vitro Culture ◽  
Oryza Sativa L ◽  
Mature Embryo ◽  
Nacl Stress ◽  
Stress Conditions ◽  
Mass Selection ◽  
Cell Membrane Stability ◽  
Culture Techniques

The progenies of 90 R0 plants regenerated from mature embryo-derived rice (Oryza sativa L.) calli obtained from two cultivars (I Kong Pao, salt-sensitive and Aiwu, moderately resistant) exposed to NaCl stress at various steps of in vitro culture, were screened for their salinity resistance in nutritive solution. Sixteen R1 families presented a higher survival rate in stress conditions than their corresponding initial cultivar and several of them exhibited an improvement in the mean number of spikelets per panicle and total grain weight produced per stressed plant. In four cases, the better behaviour of the somaclonal family could be related to physiological modifications such as a higher K+ :Na+ discrimination, preferential Na+ accumulation in the oldest leaves, lower decrease in cell membrane stability or higher tissue tolerance to internal Na+ accumulation. In some cases, these physiological properties were transmitted to R2 progenies. Heritabilities of yield-related parameters were quantified in control and stress conditions. The relationships between these parameters and the physiological behaviour of stressed material are discussed in relation to the effectiveness of in vitro culture techniques for the selection of salt-resistant plants in rice compared with a simple mass selection.

Sign in / Sign up

Export Citation Format

Share Document