Transgenic Research最新文献

Plant WRKY transcription factors are responsible for biotic and abiotic stresses and play an important role in enhancing their adaptability. The AtWRKY33 is a gene that functions in response to abiotic stresses such as low temperature, drought, salinity, etc. In this study, a recombinant vector YG8198-ZmWRKY53 carrying the ZmWRKY53, an interspecific homolog of the dicotyledonous AtWRKY33, was transferred to rice plants by Agrobacterium mediated transformation. The ectopic expression of the ZmWRKY53 in transgenic rice plants conferred cold tolerance with a higher accumulation of free proline and water-soluble sugars, an increase in chlorophyll content, a decrease in electrolyte leakage rate and MDA levels compared to control plants. This result suggests that ZmWRKY53 may confer cold tolerance in rice.

Phytoremediation is an environmental safety strategy that might serve as a viable preventative approach to reduce soil contamination in a cost-effective manner. Using plants to remediate pollution from the environment is referred to as phytoremediation. In the past few decades, plants have undergone genetic manipulation to overcome inherent limitations by using genetically modified plants. This review illustrates the eco-friendly process of cleaning the environment using transgenic strategies combined with omics technologies. Herbicides tolerance and phytoremediation abilities have been established in genetically modified plants. Transgenic plants have eliminated the pesticides atrazine and metolachlor from the soil. To expand the application of genetically engineered plants for phytoremediation process, it is essential to test strategies in the field and have contingency planning. Omics techniques were used for understanding various genetic, hormonal, and metabolic pathways responsible for phytoremediation in soil. Transcriptomics and metabolomics provide useful information as resources to understand the mechanisms behind phytoremediation. This review aims to highlight the integration of transgenic strategies and omics technologies to enhance phytoremediation efficiency, emphasizing the need for field testing and comprehensive planning for successful implementation.

Plants evolved, over millions of years, complex defense systems against pathogens. Once infected, the interaction between pathogen effector molecules and host receptors triggers plant immune responses, which include apoptosis, systemic immune response, among others. An important protein family responsible for pathogen effector recognition is the nucleotide binding site-leucine repeat rich (NBS-LRR) proteins. The NBS-LRR gene family is the largest disease resistance gene class in plants. These proteins are widely distributed in vascular plants and have a complex multigenic cluster distribution in plant genomes. To counteract the genetic load of such a large gene family on fitness cost, plants evolved a mechanism using post transcriptional gene silencing induced by small RNAs, particularly microRNAs. For the NBS-LRR gene family, the small RNAs involved in this silencing mechanism are mainly the microRNA482/2118 superfamily. This suppression mechanism is relieved upon pathogen infection, thus allowing increased NBS-LRR expression and triggering plant immunity. In this review, we will discuss the biogenesis of microRNAs and secondary RNAs involved in this silencing mechanism, biochemical and structural features of NBS-LRR proteins in response to pathogen effectors and the evolution of microRNA-based silencing mechanism with a focus on the miR482/2118 family. Furthermore, the biotechnological manipulation of microRNA expression, using both transgenic or genome editing approaches to improve cultivated plants will be discussed, with a focus on the miR482/2118 family in soybean.

The p75NTR neurotrophin receptor has positive and negative roles regulating cell survival in the nervous system. Unambiguous interpretation of p75NTR function in vivo has been complicated, however, by residual expression of alternate forms of p75NTR protein in initial p75NTR knock-out mouse models. As rats are the preferred rodent for studying brain and behaviour, and to simplify interpretation of the knock-out phenotype, we report here the generation of a mutant rat devoid of the p75NTR protein. TALEN-mediated recombination in embryonic stem cells (ESCs) was used to flank exon 2 of p75NTR with Lox P sites and produce transgenic rats carrying either un-recombined floxed p75NTR^Ex2-fl, or recombined, exon-2 deleted p75NTR^Ex2-Δ alleles. Crossing p75NTR^Ex2-fl rats with a Cre-deleter strain efficiently removed exon 2 in vivo. Excision of exon 2 causes a frameshift after p75NTR Gly23 and eliminated p75NTR protein expression. Rats lacking p75NTR were healthy, fertile, and histological analysis did not reveal significant changes in cellular density or overall structure in their brains. p75NTR function is therefore largely dispensable for normal development, growth and basal homeostasis in the rat. However, the availability of constitutive and conditional p75NTR^Ex2-Δ rats provides new opportunities to investigate specific roles of p75NTR upon injury and during tissue repair.

An essential aromatic plant, Pelargonium graveolens, does not grow well in areas where chromium contamination is a problem. Because of oxidative stress and the collapse of the photosynthetic system, crops frequently sustain severe damage. The production of excess ethylene, known as stress ethylene, which is detrimental to plant growth, the formation of roots, and early senescence, is also increased by heavy metal exposure. The effectiveness of the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase gene in transgenic Pelargonium graveolens under the control of CaMV 35S promoter was investigated to lessen the stress ethylene during chromium stress. Chromium was administered as potassium dichromate (K₂Cr₂O₇) at four distinct concentrations (100 µM, 200 µM, 300 µM, and 500 µM) to transgenic and wild-type P. graveolens and stress-induced physiological changes were monitored. Transgenic P. graveolens demonstrated greater tolerance to chromium stress than wild-type P. graveolens, as evidenced by higher leaf-relative water content, chlorophyll content, CO₂ absorption, transpiration rate, stomatal conductance, proline buildup, and antioxidant activity. The L1, L5, and L7, ACC deaminase-expressing transgenic lines also show a drop in ACC content during chromium stress, which subsequently lowered ethylene synthesis. Therefore, the reported transgenic P. graveolens lines having the ACC deaminase gene could be useful resources for growing in chromium-prone regions.

Ethylene response factors have been shown to be involved in the effects of plant developmental processes and to regulate stress tolerance. The aim of this study was to recognize the regulatory mechanisms of ethylene response factors on tobacco plant height. In this study, a gene-edited mutant (ERF10-KO) and wild type (WT) were utilized as experimental materials. Transcriptome and metabolome analyses were used to investigate the regulatory mechanism of NtERF10 gene editing on plant height in tobacco. Here, through the analysis of differentially expressed genes (DEGs), 2051 genes were upregulated and 1965 genes were downregulated. We characterized the different ERF10-KO and WT plant heights and identified key genes for photosynthesis, the plant hormone signal transduction pathway and the terpene biosynthesis pathway. NtERF10 was found to affect the growth and development of tobacco by regulating the expression levels of the PSAA, PSBA, GLY17 and GGP3 genes. Amino acid metabolism was analyzed by combining analyses of differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs). In addition, we found that members of the bHLH, NAC, MYB, and WRKY transcription factor families have vital roles in regulating plant height. This study not only provides important insights into the positive regulation of the ethylene response factor NtERF10 on plant height during plant growth and development but also provides new research ideas for tobacco molecular breeding.

The 18th Transgenic Technology Meeting, held in Houston, Texas from November 12-15, 2023, was a vibrant international forum. It brought together nearly 400 delegates to discuss advances in transgenic technologies and the science these technologies support. Among them were 329 in-person and 70 remote delegates, representing 26 countries from 5 continents. The event, hosted by the International Society for Transgenic Technologies (ISTT), was set against the backdrop of the Hyatt Regency's panoramic views, reflecting the innovative spirit of the conference. A notable precursor to the main conference was the Allele Design Pre-conference Workshop, which fostered in-depth discussions on state-of-the-art methodologies. The main conference encompassed ten sessions, delving into diverse topics from Precision Animal Models of Human Disease to the use of transgenic animals in Space Biology. Eighty posters provided for a lively exchange of ideas, while the ISTT Prize and other awards highlighted the event's commitment to excellence. Beyond the conference halls, attendees had the opportunity to venture into Houston's Museum District, home to 19 museums in the downtown area, or indulge in unique dining experiences.

Insect-protected soybean (SIP) that produces the Cry1A.105 and Cry2Ab2 insecticidal crystal proteins has been developed to provide protection from feeding damage caused by targeted lepidopteran insect pests. Typically, as part of environmental risk assessment (ERA), plant characterization is conducted, and the data submitted to regulatory agencies prior to commercialization of genetically modified (GM) crops. The objectives of this research were to: (a) compare soybean with and without the SIP trait in plant characterization field trials designed to fulfill requirements for submissions to global regulatory agencies and address China-specific considerations and (b) compare risk assessment conclusions across regions and the methodologies used in the field trials. The soybean with and without the SIP trait in temperate, tropical, and subtropical germplasm were planted in replicated multi-location trials in the USA (in 2012 and 2018) and Brazil (in 2013/2014 and 2017/2018). Agronomic, phenotypic, plant competitiveness, and survival characteristics were assessed for soybean entries with and without the SIP trait. Regardless of genetic background, growing region, season, or testing methodology, the risk assessment conclusions were the same: the evaluated insect-protected soybean did not differ from conventional soybean in evaluated agronomic, phenotypic, competitiveness, and survival characteristics indicating no change in plant pest/weed potential. These results reinforce the concept of data transportability across global regions, different seasons, germplasm, and methodologies that should be considered when assessing environmental risks of GM crops.

RNA silencing is an innate immune mechanism of plants against invasion by viral pathogens. Artificial microRNA (amiRNA) can be engineered to specifically induce RNA silencing against viruses in transgenic plants and has great potential for disease control. Here, we describe the development and application of amiRNA-based technology to induce resistance to soybean mosaic virus (SMV), a plant virus with a positive-sense single-stranded RNA genome. We have shown that the amiRNA targeting the SMV P1 coding region has the highest antiviral activity than those targeting other SMV genes in a transient amiRNA expression assay. We transformed the gene encoding the P1-targeting amiRNA and obtained stable transgenic Nicotiana benthamiana lines (amiR-P1-3-1-2-1 and amiR-P1-4-1-2-1). Our results have demonstrated the efficient suppression of SMV infection in the P1-targeting amiRNA transgenic plants in an expression level-dependent manner. In particular, the amiR-P1-3-1-2-1 transgenic plant showed high expression of amiR-P1 and low SMV accumulation after being challenged with SMV. Thus, a transgenic approach utilizing the amiRNA technology appears to be effective in generating resistance to SMV.

Δ¹-pyrroline-5-carboxylate synthetase (P5CS) is one of the key regulatory enzymes involved in the proline biosynthetic pathway. Proline acts as an osmoprotectant, molecular chaperone, antioxidant, and regulator of redox homeostasis. The accumulation of proline during stress is believed to confer tolerance in plants. In this study, we cloned the complete CDS of the P5CS from pearl millet (Pennisetum glaucum (L.) R.Br. and transformed into tobacco. Three transgenic tobacco plants with single-copy insertion were analyzed for drought and heat stress tolerance. No difference was observed between transgenic and wild-type (WT) plants when both were grown in normal conditions. However, under heat and drought, transgenic plants have been found to have higher chlorophyll, relative water, and proline content, and lower malondialdehyde (MDA) levels than WT plants. The photosynthetic parameters (stomatal conductance, intracellular CO₂ concentration, and transpiration rate) were also observed to be high in transgenic plants under abiotic stress conditions. qRT-PCR analysis revealed that the expression of the transgene in drought and heat conditions was 2-10 and 2-7.5 fold higher than in normal conditions, respectively. Surprisingly, only P5CS was increased under heat stress conditions, indicating the possibility of feedback inhibition. Our results demonstrate the positive role of PgP5CS in enhancing abiotic stress tolerance in tobacco, suggesting its possible use to increase abiotic stress-tolerance in crops for sustained yield under adverse climatic conditions.