Transgenic Research最新文献

Whether organisms developed with the use of genome editing techniques, or food derived from such organisms, are, or should be, regulated as genetically modified organisms (GMOs) or genetically modified (GM) food, respectively, remains a subject of debate globally. Much of the discussion has been scientific and focussed on the similar genetic outcomes of some genome editing techniques and 'conventional' or natural mutagenesis. Many jurisdictions, including Australia, have considered, or are considering, how their regulatory frameworks will deal with such organisms and products. In Australia, organisms developed with site directed nuclease 1 (SDN-1, with no added template to guide homology-directed repair) are not regulated as GMOs, pursuant to exclusions in the Gene Technology Regulations 2001. The exclusion of SDN-1 organisms from regulation in Australia is sometimes misrepresented, including in scientific peer reviewed publications, as extending to all genome edited organisms. This highlights the importance for researchers, developers and other stakeholders to understand that whether genome edited organisms are, or are not, subject to regulation as GMOs in a particular jurisdiction may quintessentially be a legal question, not a scientific one.

This viewpoint paper emphasises the need to diversify food production methods to simultaneously combat hunger and reduce environmental problems. The recommendations of the UN Food System Summit 2021 relate primarily to (i) the conservation of natural ecosystems, (ii) the sustainable management of existing agricultural land while increasing productivity and (iii) the restoration of already degraded land. Europe in particular faces unique challenges, such as reducing pollution and promoting organic farming up to 25 percent of the agricultural land area while maintaining food production. Ongoing efforts aim to create a transparent, fair and multi-level regulatory framework to support the Green Deal. The implementation of the Corporate Sustainability Reporting Directive (CSRD), which will sooner or later affect a larger proportion of European farmers, should support the transition. Science and innovation play a central role in this, as they are the cornerstones on which sustainable food systems are built. It is imperative that farmers actively participate in the co-design processes and utilise their wealth of experience and creativity to drive these innovations forward. A crucial aspect of the transition to sustainability is changing consumption patterns to limit food waste and reduce meat consumption. While this transition is essential, it is not without its formidable challenges. Diversification of agriculture, encompassing a spectrum of established techniques, is touted as a promising approach to achieving sustainability without sacrificing productivity. Furthermore, integrating truly sustainable agricultural practices with cutting-edge innovations, including new genomic techniques, has the potential to be a transformative solution.

Rice blast disease caused by Magnaporthe oryzae significantly reduces yield production. Blast resistance is closely associated with iron (Fe) status, but the mechanistic basis linking iron status to immune function in rice remains largely unknown. Here, iron-binding haemerythrin RING ubiquitin ligases OsHRZ1 was confirmed to play key roles in iron-mediated rice blast resistance. The expression of OsHRZ1 was suppressed by M. oryzae inoculation and high iron treatment. Both mutants of OsHRZ1 enhanced rice resistance to M. oryzae. OsPR1a was up-regulated in OsHRZ1 mutants. Yeast two-hybrid, bimolecular fluorescence complementation, and Co-IP assay results indicated that OsHRZ1 interacts with Vascular Plant One Zinc Finger 2 (OsVOZ2) in the nucleus. Additionally, the vitro ubiquitination assay indicated that OsHRZ1 can ubiquitinate OsVOZ2 and mediate the degradation of OsVOZ2. The mutants of OsVOZ2 showed reduced resistance to M. oryzae and down-regulated the expression of OsPR1a. Yeast one-hybrid, EMSA, and dual-luciferase reporter assay results indicated that OsVOZ2 directly binds to the promoter of OsPR1a, activating its expression. In summary, OsHRZ1 plays an important role in rice disease resistance by mediated degradation of OsVOZ2 thus shaping PR gene expression dynamics in rice cells. This highlights an important link between iron signaling and rice pathogen defenses.

The SARS-CoV-2 pandemic has underscored the necessity for functional transgenic animal models for testing. Mouse lines with overexpression of the human receptor ACE2 serve as the common animal model to study COVID-19 infection. Overexpression of ACE2 under a strong ubiquitous promoter facilitates convenient and sensitive testing of COVID-19 pathology. We performed pronuclear microinjections using a 5 kb CAG-ACE2 linear transgene construct and identified three founder lines with 140, 72, and 73 copies, respectively. Two of these lines were further analyzed for ACE2 expression profiles and sensitivity to SARS-CoV-2 infection. Both lines expressed ACE2 in all organs analyzed. Embryonic fibroblast cell lines derived from transgenic embryos demonstrated severe cytopathic effects following infection, even at low doses of SARS-CoV-2 (0,1-1.0 TCID₅₀). Infected mice from the two lines began to show COVID-19 clinical signs three days post-infection and succumbed between days 4 and 7. Histological examination of lung tissues from terminally ill mice revealed severe pathological alterations. To further characterize the integration site in one of the lines, we applied nanopore sequencing combined with Cas9 enrichment to examine the internal transgene concatemer structure. Oxford Nanopore sequencing (ONT) is becoming the gold standard for transgene insert characterization, but it is relatively inefficient without targeted region enrichment. We digested genomic DNA with Cas9 and gRNA against the ACE2 transgene to create ends suitable for ONT adapter ligation. ONT data analysis revealed that most of the transgene copies were arranged in a head-to-tail configuration, with palindromic junctions being rare. We also detected occasional plasmid backbone fragments within the concatemer, likely co-purified during transgene gel extraction, which is a common occurrence in pronuclear microinjections.

Genetically Modified (GM) Organisms have been used in various domains since their introduction in the 1980s. According to ISAAA data, the use of GM crops in agriculture has also increased significantly in the past 30 years. However, even after 3 decades of commercialisation, GM crops are still surrounded with controversies with different countries adopting varying approaches to their introduction in the consumer markets, owing to different stances of various stakeholders. Motivated by this multitude of opinions, and absence of knowledge mapping, this study has undertaken scientometric analysis of the publication (Web of Science) and patent (Lens.org) data about genetically modified technology use in agriculture to explore the changing knowledge patterns and technological advancements in the area. It explores both scientific and technological perspectives regarding the use of Genetically Modified Crops, by using publication as well as patent data. The findings of this study highlight the major domains of research, technology development, and leading actors in the ecosystem. These findings can be helpful in taking effective policy decisions, and furthering the research activities. It presents a composite picture using both publications and patent data. Further, it will be of utility to explore the other technologies which are replacing GM technology in agriculture in future studies.

The study by Zheng et al. (2024) identifies a NAC transcription factor, SOMBRERO (SMB), localized in the root cap of Arabidopsis, which is essential for root halotropism. SMB influences root halotropism by establishing asymmetric auxin distribution in the lateral root cap (LRC) and maintaining the expression of the auxin influx carrier gene AUX1. This mechanism leads to directional root bending away from high salinity areas. The findings reveal the SMB-AUX1-auxin module as a crucial mediator in root cap signaling and root halotropic response.

Nitrogen (N) fertilizers make up the majority of the input used in rice production, and their excess application leads to significant environmental pollution. Developing rice varieties with improved nitrogen use efficiency (NUE) is essential to maintain the sustainability of rice production. This study aims to evaluate the performance of transgenic Oryza sativa japonica cv. Kitaake expressing the barley (Hordeum vulgare) alanine aminotransferase (HvAlaAT) gene in response to different levels of N fertilizer application under tropical paddy field conditions. Results from this study demonstrate that transgenic nitrogen use efficient Kitaake rice (Kitaake NUE) displays a grain yield increase of up to 41% compared to Kitaake null. Transgenic Kitaake NUE expressing the HvAlaAT gene displays a higher N uptake and achieves a higher nitrogen use efficiency compared to control plants while maintaining lower nitrous oxide (N₂O) fluxes. The reduction in N₂O emissions in Kitaake NUE compared to Kitaake null ranges from 37.5 to 96.3%. The transgenic Kitaake NUE used in this study has potential as a donor to improve the nitrogen use efficiency of indica rice for better adaptability to tropical conditions.

NORE1A (RASSF5) is a tumor suppressor that is frequently down-regulated in liver tumors. It is an upstream component of the HIPPO pathway, a key regulator of liver development and metabolism. HIPPO disruption can lead to the development of MASLD/MASH. While studying the phenotype of NORE1A knockout mice, we noticed that they exhibit no overt liver tumor phenotype, but have a strong propensity to develop fatty livers characteristic of MASLD/MASH. Additionally, knockdown of NORE1A in liver cells upregulates sterol regulator element binding protein 1 (SREBP1), whose deregulation is central to the development MASLD. Examination of primary human MASLD samples showed an inverse correlation between the expression of NORE1A protein and TAZ, a downstream effector of the HIPPO pathway. Thus, loss of NORE1A expression may contribute to the development of MASLD/MASH in humans and NORE1A knockout mice may provide a new MASLD/MASH model that more accurately mimics the human disease.

Dehydroascorbate reductase (DHAR), an indispensable enzyme in the production of ascorbic acid (AsA) in plants, is vital for plant tolerance to various stresses. However, there is limited research on the stress tolerance functions of DHAR genes in sweet potato (Ipomoea batatas [L.] Lam). In this study, the full-length IbDHAR1 gene was cloned from the leaves of sweet potato cultivar Xu 18. The IbDHAR1 protein is speculated to be located in both the cytoplasm and the nucleus. As revealed by qRT-PCR, the relative expression level of IbDHAR1 in the proximal storage roots was much greater than in the other tissues, and could be upregulated by high-temperature, salinity, drought, and abscisic acid (ABA) stress. The results of pot experiments indicated that under high salinity and drought stress conditions, transgenic Arabidopsis and sweet potato plants exhibited decreases in H₂O₂ and MDA levels. Conversely, the levels of antioxidant enzymes APX, SOD, POD, and ACT, and the content of DHAR increased. Additionally, the ratio of AsA/DHA was greater in transgenic lines than in the wild type. The results showed that overexpression of IbDHAR1 intensified the ascorbic acid-glutathione cycle (AsA-GSH) and promoted the activity of the related antioxidant enzyme systems to improve plant stress tolerance and productivity.

A promoter is a crucial component in driving the expression of a transgene of interest for biotechnological applications in crop improvement and thus characterization of varied regulatory regions is essential. Here, we identified the promoter of COR2-like (codeinone reductase-like) from banana and characterized its tissue specific and stress inducible nature. MusaCOR2-like of banana is closely related to COR2 and CHR (chalcone reductase) sequences from different plant species and contains signature sequences including a catalytic tetrad typical of proteins with aldo-keto reductase activity. Transcript level of MusaCOR2-like was strongly induced in response to drought, salinity and exposure of signaling molecules such as abscisic acid, methyl-jasmonate and salicylic acid. Induction of MusaCOR2-like under stress strongly correlated with the presence of multiple cis-elements associated with stress responses in the P_{MusaCOR2-like} sequence isolated from Musa cultivar Rasthali. Transgenic tobacco lines harbouring P_{MusaCOR2-like}-GUS displayed visible GUS expression in vascular tissue of leaves and stem while its expression was undetectable in roots under control conditions. Exposure to drought, salinity and cold strongly induced GUS expression from P_{MusaCOR2-like}-GUS in transgenic tobacco shoots in a window period of 3H to 12H. Applications of salicylic acid, methyl-jasmonate, abscisic acid and ethephon also activate GUS in transgenic shoots at different period, with salicylic acid and abscisic acid being the stronger stimulants of P_{MusaCOR2-like}. Using P_{MusaCOR2-like}-GUS fusion and expression profiling, the current study sheds insights into a complex regulation of COR2-like, one of the least studied genes of secondary metabolite pathway in plants.