scholarly journals Progress and Challenges in the Improvement of Ornamental Plants by Genome Editing

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 687 ◽  
Author(s):  
Chang Ho Ahn ◽  
Mummadireddy Ramya ◽  
Hye Ryun An ◽  
Pil Man Park ◽  
Yae-Jin Kim ◽  
...  

Biotechnological approaches have been used to modify the floral color, size, and fragrance of ornamental plants, as well as to increase disease resistance and vase life. Together with the advancement of whole genome sequencing technologies, new plant breeding techniques have rapidly emerged in recent years. Compared to the early versions of gene editing tools, such as meganucleases (MNs), zinc fingers (ZFNs), and transcription activator-like effector nucleases (TALENs), clustered regularly interspaced short palindromic repeat (CRISPR) is capable of altering a genome more efficiently and with higher accuracy. Most recently, new CRISPR systems, including base editors and prime editors, confer reduced off-target activity with improved DNA specificity and an expanded targeting scope. However, there are still controversial issues worldwide for the recognition of genome-edited plants, including whether genome-edited plants are genetically modified organisms and require a safety evaluation process. In the current review, we briefly summarize the current progress in gene editing systems and also introduce successful/representative cases of the CRISPR system application for the improvement of ornamental plants with desirable traits. Furthermore, potential challenges and future prospects in the use of genome-editing tools for ornamental plants are also discussed.

2014 ◽  
Vol 462 (1) ◽  
pp. 15-24 ◽  
Author(s):  
David A. Wright ◽  
Ting Li ◽  
Bing Yang ◽  
Martin H. Spalding

Genome editing is the practice of making predetermined and precise changes to a genome by controlling the location of DNA DSBs (double-strand breaks) and manipulating the cell's repair mechanisms. This technology results from harnessing natural processes that have taken decades and multiple lines of inquiry to understand. Through many false starts and iterative technology advances, the goal of genome editing is just now falling under the control of human hands as a routine and broadly applicable method. The present review attempts to define the technique and capture the discovery process while following its evolution from meganucleases and zinc finger nucleases to the current state of the art: TALEN (transcription-activator-like effector nuclease) technology. We also discuss factors that influence success, technical challenges and future prospects of this quickly evolving area of study and application.


Author(s):  
Silas Obukosia ◽  
Olalekan Akinbo ◽  
Woldeyesus Sinebo ◽  
Moussa Savadogo ◽  
Samuel Timpo ◽  
...  

A new set of breeding techniques, referred to as New Breeding Techniques developed in the last two decades have potential for enhancing improved productivity in crop and animal breeding globally. These include site directed nucleases based genomic editing procedures-CRISPR and Cas associated proteins, Zinc Finger Nucleases, Meganucleases/Homing Endonucleases and Transcription- Activator Like-Effector Nucleases for genome editing and other technologies including- Oligonucleotide-Directed Mutagenesis, Cisgenesis and intragenesis, RNA-Dependent DNA methylation; Transgrafting, Agroinfiltration, Reverse breeding. There are ongoing global debates on whether the processes of and products emerging from these technologies should be regulated as genetically modified organisms or approved as conventional products. Decisions on whether to regulate as GMOs are based both on understanding of the molecular basis of their development and if the GMO intermediate step was used. For example- cisgenesis, can be developed using Agrobacterium tumefaciens methods of transformation, a process used by GMO but if the selection is properly conducted the intermediate GMO elements will be eliminated and the final product will be identical to the conventionally developed crops. Others like Site Directed Nuclease 3 are regulated as GMOs in countries such as United State of America, Canada, European Union, Argentina, Australia. Progress in genome editing research, testing of genome edited bacterial blight resistant rice, development of Guidelines for regulating new breeding techniques or genome editing in Africa is also covered with special reference to South Africa, Kenya and Nigeria. Science- and evidence-based approach to regulation of new breeding techniques among regulators and policy makers should be strongly supported.


2020 ◽  
Author(s):  
Kun Yu ◽  
Zhiqiang Liu ◽  
Huaping Gui ◽  
Lizhao Geng ◽  
Juan Wei ◽  
...  

Abstract Background Rice leaf blight is a worldwide devastating disease caused by bacteria Xanthomonas oryzae pv. Oryzae (Xoo). The UPT (up-regulated by transcription activator-like 1 effector) box in promoter region of the rice Xa13 gene played a key role in Xoo pathogenicity. Mutation of key bacterial protein binding site in UPT box of Xa13 to abolish PXO99-induced Xa13 expression is a way to improve rice resistant to bacterial.Highly efficient generation and selection transgene-free, edited plants helpful to shorten and simple the gene editing breeding process. Selective elimination of transgenic pollen of E0 plants can enrich proportion of E1 transgene-free offspring and expression of the color mark gene in seeds makes the selection of E2 plants is very convenient and efficient. In this study, a genome editing and multiplexed selection system was used to generate bacteria leaf blight resistance and transgene-free rice plants.Results We introduced site specific mutations into the UPT box using CRISPR/Cas12a technology to hamper TAL (Transcription-Activator Like effectors) protein binding and gene activation, and generated genome edited rice with improved bacteria blight resistance. Transgenic pollens of E0 plants were eliminated by pollen specific expression of α-amylase gene Zmaa1, the proportion of transgene-free plants were enriched from 25% to 50% in single T-DNA insertion events in E1 generation. Transgenic seeds were visually identified and discarded by specific aleuronic expression of DsRed, which reduced 50% cost and achieved up to 98.64% of accuracy for selection of transgene-free edited plants. Conclusion We demonstrated core nucleotide deletion in the UPT box of Xa13 promoter conferred resistance to rice blight and selection of transgene-free plants were boosted by introducing multiplexed selection. The combination of genome editing and transgene-free selection is an efficient strategy to accelerate functional genomic research and plant breeding.


2020 ◽  
Vol 21 (16) ◽  
pp. 5665 ◽  
Author(s):  
Sunny Ahmar ◽  
Sumbul Saeed ◽  
Muhammad Hafeez Ullah Khan ◽  
Shahid Ullah Khan ◽  
Freddy Mora-Poblete ◽  
...  

Genome editing is a relevant, versatile, and preferred tool for crop improvement, as well as for functional genomics. In this review, we summarize the advances in gene-editing techniques, such as zinc-finger nucleases (ZFNs), transcription activator-like (TAL) effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR) associated with the Cas9 and Cpf1 proteins. These tools support great opportunities for the future development of plant science and rapid remodeling of crops. Furthermore, we discuss the brief history of each tool and provide their comparison and different applications. Among the various genome-editing tools, CRISPR has become the most popular; hence, it is discussed in the greatest detail. CRISPR has helped clarify the genomic structure and its role in plants: For example, the transcriptional control of Cas9 and Cpf1, genetic locus monitoring, the mechanism and control of promoter activity, and the alteration and detection of epigenetic behavior between single-nucleotide polymorphisms (SNPs) investigated based on genetic traits and related genome-wide studies. The present review describes how CRISPR/Cas9 systems can play a valuable role in the characterization of the genomic rearrangement and plant gene functions, as well as the improvement of the important traits of field crops with the greatest precision. In addition, the speed editing strategy of gene-family members was introduced to accelerate the applications of gene-editing systems to crop improvement. For this, the CRISPR technology has a valuable advantage that particularly holds the scientist’s mind, as it allows genome editing in multiple biological systems.


Author(s):  
T Tahir ◽  
Q Ali ◽  
MS Rashid ◽  
A Malik

Today we can use multiple of endonucleases for genome editing which has become very important and used in number of applications. We use sequence specific molecular scissors out of which, most important are mega nucleases, zinc finger nucleases, TALENS (Transcription Activator Like-Effector Nucleases) and CRISPR-Cas9 which is currently the most famous due to a number of reasons, they are cheap, easy to build, very specific in nature and their success rate in plants and animals is also high. Who knew that one day these CRISPR discovered as a part of immune system of bacteria will be this much worthwhile in the field of genetic engineering? This review interprets the science behind their mechanism and how several advancements were made with the passage of time to make them more efficient for the assigned job.


Author(s):  
MU Farooq ◽  
MF Bashir ◽  
MUS Khan ◽  
B Iqbal ◽  
Q Ali

The study for genetic variation in plant genomes for a variety of crops, as well as developments of genome editing techniques, have made it possible to cultivate for about any desired trait. Zinc finger enzymes; have made strides in genome-editing. Molecular biologists can now more specifically target every gene using transcription activator-like effector nucleases and ZFNs. These methods, on the other hand, are expensive and time-consuming because they involve complex procedures. Referring to various genome editing techniques, CRISPR/Cas9 genetic modification is simple to construct and clone and the Cas9 could be used with different guide RNAs controlling different genes. Following solid evidence demonstrations using the main CRISPR-Cas9 unit in field crops, multiple updated Cas9 cassettes are often used in plant species to improve target precision and reduce off target cleavage. Nmcas9, Sacas9, as well as Stcas9 are a few examples. Furthermore, Cas9 enzymes are readily available from a variety of sources. Bacteria that had never been discovered before has found solutions available to improve specificity and efficacy of gene editing techniques. The choices are summarized in this analysis to plant's experiment to develop crops using CRISPR/Cas9 technology; the tolerance of biotic & abiotic stress may be improved. These strategies will lead to the growth of non-genetically engineered crops with the target phenotype, which will further improve yield capacity under biotic & abiotic stress environments.


2020 ◽  
Vol 40 (4) ◽  
Author(s):  
Matthew P. Hirakawa ◽  
Raga Krishnakumar ◽  
Jerilyn A. Timlin ◽  
James P. Carney ◽  
Kimberly S. Butler

Abstract Genome editing technologies, particularly those based on zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and CRISPR (clustered regularly interspaced short palindromic repeat DNA sequences)/Cas9 are rapidly progressing into clinical trials. Most clinical use of CRISPR to date has focused on ex vivo gene editing of cells followed by their re-introduction back into the patient. The ex vivo editing approach is highly effective for many disease states, including cancers and sickle cell disease, but ideally genome editing would also be applied to diseases which require cell modification in vivo. However, in vivo use of CRISPR technologies can be confounded by problems such as off-target editing, inefficient or off-target delivery, and stimulation of counterproductive immune responses. Current research addressing these issues may provide new opportunities for use of CRISPR in the clinical space. In this review, we examine the current status and scientific basis of clinical trials featuring ZFNs, TALENs, and CRISPR-based genome editing, the known limitations of CRISPR use in humans, and the rapidly developing CRISPR engineering space that should lay the groundwork for further translation to clinical application.


2016 ◽  
Vol 41 (3) ◽  
pp. 1-3
Author(s):  
Nicanor Pier Giorgio Austriaco ◽  

There has been much discussion regarding the proper use of the powerful CRISPR technologies that can be used to edit the genome. CRISPR is a technique borrowed from bacterial cells that will allow scientists to quickly and precisely change the DNA of nearly any organism, including humans. Unlike other gene-editing technologies, CRISPR is cheap, quick, and easy to use. In fact, do-it-yourself CRISPR genome editing kits are available online for less than $200, which will enable anyone, including so-called biohackers, to do genetic engineering at the kitchen table. In only three years—CRISPR as a genome-editing tool was first described in 2012—it is already universally acknowledged that this technology will revolutionize the life sciences. But CRISPR’s great promise has also sparked a great ethical and societal debate on its legitimate uses, most significantly on whether it should be used to alter the genomes of our children and grandchildren.


Author(s):  
Hongyi Li ◽  
Yang Yang ◽  
Weiqi Hong ◽  
Mengyuan Huang ◽  
Min Wu ◽  
...  

AbstractBased on engineered or bacterial nucleases, the development of genome editing technologies has opened up the possibility of directly targeting and modifying genomic sequences in almost all eukaryotic cells. Genome editing has extended our ability to elucidate the contribution of genetics to disease by promoting the creation of more accurate cellular and animal models of pathological processes and has begun to show extraordinary potential in a variety of fields, ranging from basic research to applied biotechnology and biomedical research. Recent progress in developing programmable nucleases, such as zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeat (CRISPR)–Cas-associated nucleases, has greatly expedited the progress of gene editing from concept to clinical practice. Here, we review recent advances of the three major genome editing technologies (ZFNs, TALENs, and CRISPR/Cas9) and discuss the applications of their derivative reagents as gene editing tools in various human diseases and potential future therapies, focusing on eukaryotic cells and animal models. Finally, we provide an overview of the clinical trials applying genome editing platforms for disease treatment and some of the challenges in the implementation of this technology.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kun Yu ◽  
Zhiqiang Liu ◽  
Huaping Gui ◽  
Lizhao Geng ◽  
Juan Wei ◽  
...  

Abstract Background Rice leaf blight, which is a devastating disease worldwide, is caused by the bacterium Xanthomonas oryzae pv. oryzae (Xoo). The upregulated by transcription activator-like 1 (UPT) effector box in the promoter region of the rice Xa13 gene plays a key role in Xoo pathogenicity. Mutation of a key bacterial protein-binding site in the UPT box of Xa13 to abolish PXO99-induced Xa13 expression is a way to improve rice resistance to bacteria. Highly efficient generation and selection of transgene-free edited plants are helpful to shorten and simplify the gene editing-based breeding process. Selective elimination of transgenic pollen of T0 plants can enrich the proportion of T1 transgene-free offspring, and expression of a color marker gene in seeds makes the selection of T2 plants very convenient and efficient. In this study, a genome editing and multiplexed selection system was used to generate bacterial leaf blight-resistant and transgene-free rice plants. Results We introduced site-specific mutations into the UPT box using CRISPR/Cas12a technology to hamper with transcription-activator-like effector (TAL) protein binding and gene activation and generated genome-edited rice with improved bacterial blight resistance. Transgenic pollen of T0 plants was eliminated by pollen-specific expression of the α-amylase gene Zmaa1, and the proportion of transgene-free plants increased from 25 to 50% among single T-DNA insertion events in the T1 generation. Transgenic seeds were visually identified and discarded by specific aleuronic expression of DsRed, which reduced the cost by 50% and led to up to 98.64% accuracy for the selection of transgene-free edited plants. Conclusion We demonstrated that core nucleotide deletion in the UPT box of the Xa13 promoter conferred resistance to rice blight, and selection of transgene-free plants was boosted by introducing multiplexed selection. The combination of genome editing and transgene-free selection is an efficient strategy to accelerate functional genomic research and plant breeding.


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