Transgene expression and agronomic improvement of rice

1993 ◽  
Vol 342 (1301) ◽  
pp. 197-201 ◽  
Keyword(s):  
Transgenic Plants ◽  
Triosephosphate Isomerase ◽  
Viral Infections ◽  
Specific Protein ◽  
Coding Region ◽  
Gene Encoding ◽  
Gus Reporter ◽  
Genes Encoding ◽  
Flanking Region ◽  
Viral Sequences

A reliable system for transformation and regeneration of rice protoplasts yielding fertile transgenic plants has been established. After co-electroporation of DNAs encoding a selectable marker and the gene of interest, protoplasts are regenerated to yield fertile plants. To date more than 70 different genes of interest have been successfully introduced and their patterns of expression are being studied. As in the case of dicot plants transformed by the Ti-plasm id vector approach, integration and expression appear to be stable in the transgenic monocots over several generations. Detailed com parative studies on gene expression in rice are underway using promoters for triosephosphate isomerase, a ubiquitously expressed gene encoding a cytosolic enzyme vital in the glycolytic cycle, two genes encoding members of the cyclophilin family, peptidyl-prolyl cis-trans -isomerases that are abundant in meristematic regions and are thought to participate in the correct folding of nascent proteins, and a gene encoding a tissue (root)- specific protein. Initial analyses suggest that the spatial expression of these genes in transgenic plants, using GUS reporter constructs, appears to be very sensitive to the nature of the 3' flanking region present in the gene construct. Constructs containing a coding region for arcelin, a bean seed protein with putative anti-insecticidal properties, and others containing viral sequences that may provide novel approaches for protection against tungro and other viral infections have been introduced into rice plants.

Plant pre-m RNA splicing and splicing components

1993 ◽  
Vol 342 (1301) ◽  
pp. 217-224 ◽  
Keyword(s):  
Transgenic Plants ◽  
Rna Splicing ◽  
Specific Protein ◽  
Messenger Rnas ◽  
Rna Helicases ◽  
Gene Encoding ◽  
Small Nuclear Ribonucleoprotein ◽  
Genes Encoding ◽  
Snrnp Protein

Pre-mRNA splicing or the removal of introns from precursor messenger RNAs depends on the accurate recognition of intron sequences by the plant splicing machinery. The major components of this machinery are small nuclear ribonucleoprotein protein particles (snRNPs) which consist of snRNAs and snRNP proteins. We have analysed various aspects of intron sequence and structure in relation to splice site selection and splicing efficiency and we have cloned snRNA genes and a gene encoding the snRNP protein, U2B". In the absence of an in vitro splicing system for plants, transient expression in protoplasts and stable plant transform ations have been used to analyse splicing of intron constructs. We aim to address the function of the UsnRNP-specific protein, U2B", via the production of transgenic plants expressing antisense U2B" transcripts and epitope-tagged U2B" protein. In addition, we have cloned genes encoding other proteins which potentially interact with RNA, such as RNA helicases, and strategies involving transgenic plants are being developed to analyse their function.

scholarly journals Virus Synergy in Transgenic Plants

2000 ◽  
Author(s):  
Peter Palukaitis ◽  
Amit Gal-On ◽  
Milton Zaitlin ◽  
Victor Gaba
Keyword(s):  
Transgenic Plants ◽  
Plant Species ◽  
Natural Resistance ◽  
Virus Accumulation ◽  
Synergistic Interactions ◽  
Viral Genes ◽  
Genes Encoding ◽  
Movement Synergy ◽  
Plant Genes ◽  
Viral Sequences

Transgenic plants expressing viral genes offer novel means of engendering resistance to those viruses. However, some viruses interact synergistically with other viruses and it is now known that transgenic plants expressing particular genes of one virus may also mediate synergy with a second virus. Thus, our specific objectives were to (1) determine if transgenic plants resistant to one virus showed synergy with another virus; (2) determine what viral sequences were essential for synergy; and (3) determine whether one of more mechanisms were involved i synergy. This project would also enable an evaluation of the risks of synergism associated with the use of such transgenic plants. The conclusion deriving from this project are as follows: - There is more than one mechanism of synergy. - The CMV 2b gene is required for synergistic interactions. - Synergy between a potyvirus and CMV can break natural resistance limiting CMV movement. - Synergy operates at two levels - increase in virus accumulation and increase in pathology - independently of each other. - Various sequences of CMV can interact with the host to alter pathogenicity and affect virus accumulation. - The effect of synergy on CMV satellite RNA accumulatio varies in different systems. - The HC-Pro gene may only function in host plant species to induce synergy. - The HC-Pro is a host range determinant of potyviruses. - Transgenic plants expressing some viral sequences showed synergy with one or more viruses. Transgenic plants expressing CMV RNA 1, PVY NIb and the TMV 30K gene all showed synergy with at least one unrelated virus. - Transgenic plants expressing some viral sequences showed interference with the infection of unrelated viruses. Transgenic plants expressing the TMV 30K, 54K and 126K genes, the PVY NIb gene, or the CMV 3a gene all showed some level of interference with the accumulation (and in some cases the pathology) of unrelated viruses. From our observations, there are agricultural implications to the above conclusions. It is apparent that before they are released commercially, transgenic plants expressing viral sequences for resistance to one virus need to be evaluated fro two properties: - Synergism to unrelated viruses that infect the same plant. Most of these evaluations can be made in the greenhouse, and many can be predicted from the known literature of viruses known to interact with each other. In other cases, where transgenic plants are being generated from new plant species, the main corresponding viruses from the same known interacting genera (e.g., potexviruses and cucumoviruses, potyviruses and cucumoviruses, tobamoviruses and potexviruses, etc.) should be evaluated. - Inhibition or enhancement of other resistance genes. Although it is unlikely that plants to be released would be transformed with HC-Pro or 2b genes, there may be other viral genes that can affect the expression of plant genes encoding resistance to other pathogens. Therefore, transgenic plants expressing viral genes to engender pathogen-derived resistance should be evaluated against a spectrum of other pathogens, to determine whether those resistance activities are still present, have been lost, or have been enhanced!

scholarly journals Analysis of recombination between viral RNAs and transgene mRNA under conditions of high selection pressure in favour of recombinants

2009 ◽  
Vol 90 (11) ◽  
pp. 2798-2807 ◽  
Author(s):  
Marco Morroni ◽  
Jeremy R. Thompson ◽  
Mark Tepfer
Keyword(s):  
Transgenic Plants ◽  
Selection Pressure ◽  
In Planta ◽  
Coding Region ◽  
Tobacco Plants ◽  
Viral Rnas ◽  
Transgenic Lines ◽  
High Selection ◽  
The One ◽  
Viral Sequences

One possible environmental risk related to the utilization of virus-resistant transgenic plants expressing viral sequences is the emergence of new viruses generated by recombination between the viral transgene mRNA and the RNA of an infecting virus. This hypothesis has been tested recently for cucumber mosaic virus (CMV) by comparing the recombinant populations in transgenic and non-transgenic plants under conditions of minimal selection pressure in favour of the recombinants. Equivalent populations were observed in transgenic and non-transgenic plants but, in both, there was a strongly dominant hotspot recombinant which was shown recently to be nonviable alone in planta, suggesting that its predominance could be reduced by applying an increased selection pressure in favour of viable recombinants. Partially disabled I17F-CMV mutants were created by engineering 6 nt deletions in five sites in the RNA3 3′-non-coding region (3′-NCR). One mutant was used to inoculate transgenic tobacco plants expressing the coat protein and 3′-NCR of R-CMV. A total of 22 different recombinant types were identified, of which 12 were, as expected, between the transgene mRNA and the mutated I17F-CMV RNA3, while 10 resulted from recombination between the mutated RNA3 and I17F-CMV RNA1. Twenty recombinants were of the aberrant type, while two, including the dominant one detected previously under conditions of minimal selection pressure, were homologous recombinants. All recombinants detected were very similar to ones observed in nature, suggesting that the deployment of transgenic lines similar to the one studied here would not lead to the emergence of new viruses.

Evolutionary conservation of the insulin gene structure in invertebrates: cloning of the gene encoding molluscan insulin-related peptide III from Lymnaea stagnalis

1993 ◽  
Vol 11 (1) ◽  
pp. 103-113 ◽  
Author(s):  
A B Smit ◽  
A van Marle ◽  
R van Elk ◽  
J Bogerd ◽  
H van Heerikhuizen ◽  
...  
Keyword(s):  
Lymnaea Stagnalis ◽  
Structural Characteristics ◽  
Freshwater Snail ◽  
Coding Region ◽  
Gene Encoding ◽  
Related Peptide ◽  
Genes Encoding ◽  
The Common ◽  
Type Gene ◽  
The Brain

ABSTRACT Although insulins and structurally related peptides are found in vertebrates as well as in invertebrates, it is not clear whether the genes encoding these hormones have emerged from a single ancestral (insulin)-type of gene or, alternatively, have arisen independently through convergent evolution from different types of gene. To investigate this issue, we cloned the gene encoding the molluscan insulin-related peptide III (MIP III) from the freshwater snail, Lymnaea stagnalis. The predicted MIP III preprohormone had the overall organization of preproinsulin, with a signal peptide and A and B chains, connected by two putative C peptides. Although MIP III was found to share key features with vertebrate insulins, it also had unique structural characteristics in common with the previously identified MIPs I and II, thus forming a distinct class of MIP peptides within the insulin superfamily. MIP III is synthesized in neurones in the brain. It is encoded by a gene with the overall organization of the vertebrate insulin genes, with three exons and two introns, of which the second intron interrupts the coding region of the C peptides. Our data therefore demonstrate that in the Archaemetazoa, the common ancestor of the vertebrates and invertebrates, a primordial peptide with a two-chain insulin configuration encoded by a primordial insulin-type gene must have been present.

scholarly journals Genomic and Proteomic Comparative Analysis of SARS-CoV-2 versus SARS-CoV-GD01

2020 ◽  
Author(s):  
Abdallah A. Hassanin ◽  
EL-Sayed I. Mahgoub ◽  
Basel Sitohy ◽  
Mahmoud Sitohy
Keyword(s):  
Bioinformatics Analysis ◽  
Viral Infections ◽  
Antiviral Agents ◽  
Cell Receptor ◽  
Gene Encoding ◽  
Spike Gene ◽  
Insertion And Deletion ◽  
Host Cell Receptor ◽  
Genes Encoding ◽  
Pathogenic Action

Abstract Background Since the emergence of the pandemic novel pneumonia (COVID-19) disease in Wuhan city in China in November 2019, it is becoming holistically urgent to discover and definitely determine the potential origin of causative virus of this disease, SARS-CoV2 to understand its pathogenic action an better design proper remedies. Methods Using bioinformatics analysis, the whole genome of SARS-CoV2 emerging in 2020 and its deduced proteome were compared with the corresponding information on SARS-CoV-GD01 having emerged in 2003 in China. The genomes squences of the two viruses were obtained from NCBI. Alignment of protein sequences for all genes of both genomes were performed and displayed using Clustal Omega data base. Results Bioinformatics analysis revealed 10 genes encoding 10 proteins in the SARS-CoV2 genome instead of 11 genes encoding 12 proteins in the case of SARS-CoV-GD01, where the first gene is uniquely encoding two glycoproteins. Additionally, bio-informatics analysis disclosed variations in SARS-CoV2 genome size as a result of nucleotides insertion and deletion in all genes of the virus especially orf1ab gene, spike gene, and ORF10 gene. The most conspicuous alteration is apparently noticed in the spike gene, encoding for a novel protein enabling the virus to attach to the cell membrane via the interaction with host cell receptor, initiating probably a new pathway of infection and a specific pathogenic action. This alteration is Conclusions The big alterations in the genome of SARS-CoV-2 from that of SARS-CoV-GD01 may be potentially responsible for the worldwide witnessed high virulence and accelerated spread. The qualified and quantified information presented in the current study on the SARS-CoV-2, detailing the specificity and the magnitude of genomic and proteomic alterations from SARS-CoV-GD01, developed probably during 16 years will not only enable designing right drugs and strategies of confronting the current viral version, but it may rather allow to extrapolate and foresee potential outbreaks of newer versions during the coming decades. At the time of epidemics, nonspecific ways and drugs should be resorted to for confronting emergent viral infections. Chemically modified positively charged proteins and peptides can offer a wealth of potential antiviral agents but need more clinical research.

scholarly journals Unmasking viral sequences by metagenomic next-generation sequencing in adult human blood samples during steroid-refractory/dependent graft-versus-host disease

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
M. C. Zanella ◽  
S. Cordey ◽  
F. Laubscher ◽  
M. Docquier ◽  
G. Vieille ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Graft Versus Host Disease ◽  
Rubella Virus ◽  
Viral Infections ◽  
Next Generation ◽  
Host Disease ◽  
Graft Versus Host ◽  
Viral Sequences ◽  
Generation Sequencing ◽  
Steroid Refractory

Abstract Background Viral infections are common complications following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Allo-HSCT recipients with steroid-refractory/dependent graft-versus-host disease (GvHD) are highly immunosuppressed and are more vulnerable to infections with weakly pathogenic or commensal viruses. Here, twenty-five adult allo-HSCT recipients from 2016 to 2019 with acute or chronic steroid-refractory/dependent GvHD were enrolled in a prospective cohort at Geneva University Hospitals. We performed metagenomics next-generation sequencing (mNGS) analysis using a validated pipeline and de novo analysis on pooled routine plasma samples collected throughout the period of intensive steroid treatment or second-line GvHD therapy to identify weakly pathogenic, commensal, and unexpected viruses. Results Median duration of intensive immunosuppression was 5.1 months (IQR 5.5). GvHD-related mortality rate was 36%. mNGS analysis detected viral nucleotide sequences in 24/25 patients. Sequences of ≥ 3 distinct viruses were detected in 16/25 patients; Anelloviridae (24/25) and human pegivirus-1 (9/25) were the most prevalent. In 7 patients with fatal outcomes, viral sequences not assessed by routine investigations were identified with mNGS and confirmed by RT-PCR. These cases included Usutu virus (1), rubella virus (1 vaccine strain and 1 wild-type), novel human astrovirus (HAstV) MLB2 (1), classic HAstV (1), human polyomavirus 6 and 7 (2), cutavirus (1), and bufavirus (1). Conclusions Clinically unrecognized viral infections were identified in 28% of highly immunocompromised allo-HSCT recipients with steroid-refractory/dependent GvHD in consecutive samples. These identified viruses have all been previously described in humans, but have poorly understood clinical significance. Rubella virus identification raises the possibility of re-emergence from past infections or vaccinations, or re-infection.

scholarly journals Expression and function of the cdgD gene, encoding a CHASE–PAS-DGC-EAL domain protein, in Azospirillum brasilense

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Francisco Cruz-Pérez ◽  
Roxana Lara-Oueilhe ◽  
Cynthia Marcos-Jiménez ◽  
Ricardo Cuatlayotl-Olarte ◽  
María Luisa Xiqui-Vázquez ◽  
...  
Keyword(s):  
Azospirillum Brasilense ◽  
Type Strain ◽  
Wild Type Strain ◽  
Soil Conditions ◽  
Wild Type ◽  
Gene Encoding ◽  
Wheat Roots ◽  
Genes Encoding ◽  
In The Wild ◽  
Plant Growth Promoting

AbstractThe plant growth-promoting bacterium Azospirillum brasilense contains several genes encoding proteins involved in the biosynthesis and degradation of the second messenger cyclic-di-GMP, which may control key bacterial functions, such as biofilm formation and motility. Here, we analysed the function and expression of the cdgD gene, encoding a multidomain protein that includes GGDEF-EAL domains and CHASE and PAS domains. An insertional cdgD gene mutant was constructed, and analysis of biofilm and extracellular polymeric substance production, as well as the motility phenotype indicated that cdgD encoded a functional diguanylate protein. These results were correlated with a reduced overall cellular concentration of cyclic-di-GMP in the mutant over 48 h compared with that observed in the wild-type strain, which was recovered in the complemented strain. In addition, cdgD gene expression was measured in cells growing under planktonic or biofilm conditions, and differential expression was observed when KNO3 or NH4Cl was added to the minimal medium as a nitrogen source. The transcriptional fusion of the cdgD promoter with the gene encoding the autofluorescent mCherry protein indicated that the cdgD gene was expressed both under abiotic conditions and in association with wheat roots. Reduced colonization of wheat roots was observed for the mutant compared with the wild-type strain grown in the same soil conditions. The Azospirillum-plant association begins with the motility of the bacterium towards the plant rhizosphere followed by the adsorption and adherence of these bacteria to plant roots. Therefore, it is important to study the genes that contribute to this initial interaction of the bacterium with its host plant.

Structure, expression, chromosomal location and product of the gene encoding Adh2 in Petunia.

Genetics ◽  
1993 ◽  
Vol 133 (4) ◽  
pp. 999-1007
Author(s):  
R G Gregerson ◽  
L Cameron ◽  
M McLean ◽  
P Dennis ◽  
J Strommer
Keyword(s):  
Chromosomal Location ◽  
Higher Plants ◽  
Gene Encoding ◽  
Genomic Libraries ◽  
Regulatory Strategy ◽  
Adh1 Gene ◽  
Adh Genes ◽  
Genes Encoding ◽  
Adh Gene ◽  
Polymerase Chain

Abstract In most higher plants the genes encoding alcohol dehydrogenase comprise a small gene family, usually with two members. The Adh1 gene of Petunia has been cloned and analyzed, but a second identifiable gene was not recovered from any of three genomic libraries. We have therefore employed the polymerase chain reaction to obtain the major portion of a second Adh gene. From sequence, mapping and northern data we conclude this gene encodes ADH2, the major anaerobically inducible Adh gene of Petunia. The availability of both Adh1 and Adh2 from Petunia has permitted us to compare their structures and patterns of expression to those of the well-studied Adh genes of maize, of which one is highly expressed developmentally, while both are induced in response to hypoxia. Despite their evolutionary distance, evidenced by deduced amino acid sequence as well as taxonomic classification, the pairs of genes are regulated in strikingly similar ways in maize and Petunia. Our findings suggest a significant biological basis for the regulatory strategy employed by these distant species for differential expression of multiple Adh genes.

scholarly journals Mutations in calphotin, the gene encoding a Drosophila photoreceptor cell-specific calcium-binding protein, reveal roles in cellular morphogenesis and survival.

Genetics ◽  
1994 ◽  
Vol 138 (2) ◽  
pp. 413-421 ◽  
Author(s):  
Y Yang ◽  
D Ballinger
Keyword(s):  
Calcium Binding ◽  
Photoreceptor Cell ◽  
Cell Structure ◽  
Specific Protein ◽  
Cell Organelle ◽  
Cell Type ◽  
Gene Encoding ◽  
Cellular Morphogenesis ◽  
Transgenic Flies ◽  
Drosophila Photoreceptor

Abstract Calphotin is a Drosophila photoreceptor cell-specific protein expressed very early in eye development, at the time when cell-type decisions are being made. Calphotin is a very hydrophobic and proline-rich protein which lacks obvious transmembrane domains. The cDNA encoding Calphotin was mapped to a region removed by a set of existing chromosomal deletions. Mutations that alter photoreceptor cell structure and development were isolated that fail to complement these deletions. These mutations fall into two classes. Class I mutations alter the structure of the rhabdomere, a photoreceptor cell organelle specialized for phototransduction. Class II mutations have rough eyes, due to misorientation of the rhabdomeres and photoreceptor cell death. Transformation rescue of these phenotypes in transgenic flies bearing calphotin genomic DNA indicates that both classes of mutations are in the calphotin gene. Analysis of these mutations suggest that Calphotin plays important roles in both rhabdomere development and in photoreceptor cell survival.

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