scholarly journals Transgenic plants expressing immunosuppressive dsRNA improve entomopathogen efficacy against Spodoptera littoralis larvae

2022 ◽  
Author(s):  
Ilaria Di Lelio ◽  
Eleonora Barra ◽  
Mariangela Coppola ◽  
Giandomenico Corrado ◽  
Rosa Rao ◽  
...  
Keyword(s):  
Immune Response ◽  
Bacillus Thuringiensis ◽  
Transgenic Plants ◽  
Food Consumption ◽  
Spodoptera Littoralis ◽  
Tobacco Plants ◽  
Double Stranded Rna ◽  
Killing Activity ◽  
Lepidopteran Larvae ◽  
Lepidopteran Pest

AbstractTransgenic plants that express double-stranded RNA (dsRNA) targeting vital insect genes have recently emerged as a valuable new tool for pest control. In this study, tobacco plants were transformed to produce dsRNA targeting Sl 102 gene that is involved in the immune response of Spodoptera littoralis larvae, a serious lepidopteran pest of several crops. Experimental larvae reared on transgenic tobacco lines showed (1) a strongly reduced level of Sl 102 transcripts, which was positively associated with food consumption; (2) a substantial impairment of the encapsulation response mediated by hemocytes; and (3) a marked increase in the susceptibility to Xentari™, a Bacillus thuringiensis-based insecticide. Importantly, this approach may allow a reduction in the doses of B. thuringiensis used for field applications and enhance its killing activity on mature larvae. The results obtained thus support the use of immunosuppressive RNAi plants to enhance the performance of microbial insecticides on lepidopteran larvae.

The cryic gene from Bacillus thuringiensis provides protection against Spodoptera littoralis in young transgenic plants

Plant Science ◽  
1997 ◽  
Vol 127 (2) ◽  
pp. 179-190 ◽  
Author(s):  
Marianne Mazier ◽  
Josette Chaufaux ◽  
Vincent Sanchis ◽  
Didier Lereclus ◽  
Marc Giband ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Transgenic Plants ◽  
Spodoptera Littoralis

scholarly journals The frequency of T-DNA integration during the genetic transformation of tobacco (Nicotiana tabacum L.)

2018 ◽  
Vol 22 ◽  
pp. 262-266
Author(s):  
A. G. Komisarenko ◽  
S. I. Mykhalska ◽  
O. O. Khrystan
Keyword(s):  
Nicotiana Tabacum ◽  
Transgenic Plants ◽  
Transformation Frequency ◽  
Tobacco Plants ◽  
Double Stranded Rna ◽  
Dna Integration ◽  
Agrobacterium Mediated Transformation ◽  
Nicotiana Tabacum L ◽  
Is Integration

Aim. Investigation of the is integration frequency of the genes and their components (elements of genetic constructions) in transgenic tobacco-regenerating plants. Methods. Agrobacterium-mediated transformation of tobacco (Nicotiana tabacum L.) in vitro. Results. There were obtained tobacco plants with integrated target and selective genes. It was found that a complete copy of T-DNA or its certain elements were embedded. Conclusions. The possibility of the integration of complete and incomplete DNA copies during in vitro Agrobacterium-mediated transformation of the Nicotiana tabacum were established. This event were observed both during manipulations with pBi2E plasmid with the double-stranded RNA PHD gene suppressor and pBi-OAT plasmid with OAT gene. The transformation frequency with the complete integration of the genetic construction was 91 %. The integration frequencies for various plasmids were: LBA4404 pBi2E – 78 %; AGLO pBi2E – 100 %; AGLO pBi-OAT – 94 %. Keywords: Nicotiana tabacum L., Agrobacterium-mediated transformation in vitro, transgenic plants, T-DNA.

scholarly journals Topical Application of Double-Stranded RNA Targeting 2b and CP Genes of Cucumber mosaic virus Protects Plants against Local and Systemic Viral Infection

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 963
Author(s):  
Maria C. Holeva ◽  
Athanasios Sklavounos ◽  
Rajendran Rajeswaran ◽  
Mikhail M. Pooggin ◽  
Andreas E. Voloudakis
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Topical Application ◽  
Plant Virus ◽  
Plant Protection ◽  
Post Inoculation ◽  
Tobacco Plants ◽  
Double Stranded Rna

Cucumber mosaic virus (CMV) is a destructive plant virus with worldwide distribution and the broadest host range of any known plant virus, as well as a model plant virus for understanding plant–virus interactions. Since the discovery of RNA interference (RNAi) as a major antiviral defense, RNAi-based technologies have been developed for plant protection against viral diseases. In plants and animals, a key trigger of RNAi is double-stranded RNA (dsRNA) processed by Dicer and Dicer-like (DCL) family proteins in small interfering RNAs (siRNAs). In the present study, dsRNAs for coat protein (CP) and 2b genes of CMV were produced in vitro and in vivo and applied onto tobacco plants representing a systemic solanaceous host as well as on a local host plant Chenopodium quinoa. Both dsRNA treatments protected plants from local and systemic infection with CMV, but not against infection with unrelated viruses, confirming sequence specificity of antiviral RNAi. Antiviral RNAi was effective when dsRNAs were applied simultaneously with or four days prior to CMV inoculation, but not four days post inoculation. In vivo-produced dsRNAs were more effective than the in vitro-produced; in treatments with in vivo dsRNAs, dsRNA-CP was more effective than dsRNA-2b, while the effects were opposite with in vitro dsRNAs. Illumina sequencing of small RNAs from in vivo dsRNA-CP treated and non-treated tobacco plants revealed that interference with CMV infection in systemic leaves coincides with strongly reduced accumulation of virus-derived 21- and 22-nucleotide (nt) siRNAs, likely generated by tobacco DCL4 and DCL2, respectively. While the 21-nt class of viral siRNAs was predominant in non-treated plants, 21-nt and 22-nt classes accumulated at almost equal (but low) levels in dsRNA treated plants, suggesting that dsRNA treatment may boost DCL2 activity. Taken together, our findings confirm the efficacy of topical application of dsRNA for plant protection against viruses and shed more light on the mechanism of antiviral RNAi.

scholarly journals Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

2021 ◽  
Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Transgenic Tobacco ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

scholarly journals Channeling of Eukaryotic Diacylglycerol into the Biosynthesis of Plastidial Phosphatidylglycerol

2006 ◽  
Vol 282 (7) ◽  
pp. 4613-4625 ◽  
Author(s):  
Markus Fritz ◽  
Heiko Lokstein ◽  
Dieter Hackenberg ◽  
Ruth Welti ◽  
Mary Roth ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Transgenic Plants ◽  
Phosphatidic Acid ◽  
Lipid Analysis ◽  
Photosynthetic Apparatus ◽  
Hexadecenoic Acid ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants

Plastidial glycolipids contain diacylglycerol (DAG) moieties, which are either synthesized in the plastids (prokaryotic lipids) or originate in the extraplastidial compartment (eukaryotic lipids) necessitating their transfer into plastids. In contrast, the only phospholipid in plastids, phosphatidylglycerol (PG), contains exclusively prokaryotic DAG backbones. PG contributes in several ways to the functions of chloroplasts, but it is not known to what extent its prokaryotic nature is required to fulfill these tasks. As a first step toward answering this question, we produced transgenic tobacco plants that contain eukaryotic PG in thylakoids. This was achieved by targeting a bacterial DAG kinase into chloroplasts in which the heterologous enzyme was also incorporated into the envelope fraction. From lipid analysis we conclude that the DAG kinase phosphorylated eukaryotic DAG forming phosphatidic acid, which was converted into PG. This resulted in PG with 2–3 times more eukaryotic than prokaryotic DAG backbones. In the newly formed PG the unique Δ3-trans-double bond, normally confined to 3-trans-hexadecenoic acid, was also found in sn-2-bound cis-unsaturated C18 fatty acids. In addition, a lipidomics technique allowed the characterization of phosphatidic acid, which is assumed to be derived from eukaryotic DAG precursors in the chloroplasts of the transgenic plants. The differences in lipid composition had only minor effects on measured functions of the photosynthetic apparatus, whereas the most obvious phenotype was a significant reduction in growth.

scholarly journals Effect of nuclear matrix attachment regions on transgene expression in tobacco plants.

2001 ◽  
Vol 48 (3) ◽  
pp. 637-646 ◽  
Author(s):  
W Nowak ◽  
M Gawłowska ◽  
A Jarmołowski ◽  
J Augustyniak
Keyword(s):  
Transgenic Plants ◽  
Reporter Gene ◽  
Transgene Expression ◽  
Binary Vector ◽  
Special Property ◽  
Matrix Attachment Regions ◽  
Plant Populations ◽  
Tobacco Plants ◽  
Gus Reporter ◽  
Loop Domains

Matrix attachment regions (MARs) are thought to participate in the organization and segregation of independent chromosomal loop domains. Although there are several reports on the action of natural MARs in the context of heterologous genes in transgenic plants, in our study we tested a synthetic MAR (sMAR) with the special property of unpairing when under superhelical strain, for its effect on reporter gene expression in tobacco plants. The synthetic MAR was a multimer of a short sequence from the MAR 3' end of the immunoglobulin heavy chain (IgH) enhancer. This sMAR sequence was used to flank the beta-glucuronidase (GUS) reporter gene within the T-DNA of the binary vector pBI121. Vectors with or without the sMARs were then used to transform tobacco plants by Agrobacterium tumefaciens. Transgenic plants containing the sMAR sequences flanking the GUS gene exhibited higher levels of transgene expression compared with transgenic plants which lacked the sMARs. This effect was observed independently of the position of the sMAR at the 5' side of the reporter gene. However, variation of the detected transgene expression was significant in all transformed plant populations, irrespective of the construct used.

scholarly journals Overexpression of NtCBL5A Leads to Necrotic Lesions by Enhancing Na+ Sensitivity of Tobacco Leaves Under Salt Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingjing Mao ◽  
Jiaping Yuan ◽  
Zhijie Mo ◽  
Lulu An ◽  
Sujuan Shi ◽  
...  
Keyword(s):  
Immune Response ◽  
Salt Stress ◽  
Stress Response ◽  
Transcriptome Profiling ◽  
Tobacco Plants ◽  
Salt Stress Response ◽  
Cation Homeostasis ◽  
Constitutive Overexpression ◽  
Plant Photosynthesis ◽  
Sensor Proteins

Many tobacco (Nicotiana tabacum) cultivars are salt-tolerant and thus are potential model plants to study the mechanisms of salt stress tolerance. The CALCINEURIN B-LIKE PROTEIN (CBL) is a vital family of plant calcium sensor proteins that can transmit Ca2+ signals triggered by environmental stimuli including salt stress. Therefore, assessing the potential of NtCBL for genetic improvement of salt stress is valuable. In our studies on NtCBL members, constitutive overexpression of NtCBL5A was found to cause salt supersensitivity with necrotic lesions on leaves. NtCBL5A-overexpressing (OE) leaves tended to curl and accumulated high levels of reactive oxygen species (ROS) under salt stress. The supersensitivity of NtCBL5A-OE leaves was specifically induced by Na+, but not by Cl−, osmotic stress, or drought stress. Ion content measurements indicated that NtCBL5A-OE leaves showed sensitivity to the Na+ accumulation levels that wild-type leaves could tolerate. Furthermore, transcriptome profiling showed that many immune response-related genes are significantly upregulated and photosynthetic machinery-related genes are significantly downregulated in salt-stressed NtCBL5A-OE leaves. In addition, the expression of several cation homeostasis-related genes was also affected in salt-stressed NtCBL5A-OE leaves. In conclusion, the constitutive overexpression of NtCBL5A interferes with the normal salt stress response of tobacco plants and leads to Na+-dependent leaf necrosis by enhancing the sensitivity of transgenic leaves to Na+. This Na+ sensitivity of NtCBL5A-OE leaves might result from the abnormal Na+ compartmentalization, plant photosynthesis, and plant immune response triggered by the constitutive overexpression of NtCBL5A. Identifying genes and pathways involved in this unusual salt stress response can provide new insights into the salt stress response of tobacco plants.

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