scholarly journals Improved Transformation and Regeneration of Indica Rice: Disruption of SUB1A as a Test Case via CRISPR-Cas9

2021 ◽  
Vol 22 (13) ◽  
pp. 6989
Author(s):  
Yuya Liang ◽  
Sudip Biswas ◽  
Backki Kim ◽  
Julia Bailey-Serres ◽  
Endang M. Septiningsih

Gene editing by use of clustered regularly interspaced short palindromic repeats (CRISPR) has become a powerful tool for crop improvement. However, a common bottleneck in the application of this approach to grain crops, including rice (Oryza sativa), is efficient vector delivery and calli regeneration, which can be hampered by genotype-dependent requirements for plant regeneration. Here, methods for Agrobacterium-mediated and biolistic transformation and regeneration of indica rice were optimized using CRISPR-Cas9 gene-editing of the submergence tolerance regulator SUBMERGENCE 1A-1 gene of the cultivar Ciherang-Sub1. Callus induction and plantlet regeneration methods were optimized for embryogenic calli derived from immature embryos and mature seed-derived calli. Optimized regeneration (95%) and maximal editing efficiency (100%) were obtained from the immature embryo-derived calli. Phenotyping of T1 seeds derived from the edited T0 plants under submergence stress demonstrated inferior phenotype compared to their controls, which phenotypically validates the disruption of SUB1A-1 function. The methods pave the way for rapid CRISPR-Cas9 gene editing of recalcitrant indica rice cultivars.

Author(s):  
Aananthi. N

Five rice cultivars viz., ASD 16, White Ponni, Pusa Basmati 1, Pusa Sugandh 4 and Pusa Sugandh 5 belonging to subspecies indica were compared for its ability in callus formation and regeneration. In this experiment, the different parameters viz., the effect of hormones (2,4-D and kinetin), organic supplement (coconut milk O1-CM 100 mll-1, O2-CM 75 mll-1, O3-CM 50 mll-1), explants (seed and immature embryo), media (MS and N6), carbon source (sucrose and maltose) using five genotypes on callus response was studied. The effect of hardening methods was also assessed. Results showed that for enhanced callus induction was with MS medium supplemented with 2.0 mgl-1 2, 4-D + 0.5 mgl-1 kinetin + 30 gl-1 maltose irrespective of explants used. Addition of 100 ml l-1 coconut milk was found have improvement in callus response. The performance of immature embryo was better than seed for callus induction, emrbyogenic callus formation, rhizogenic callus formation and regeneration. MS media provided superiority over N6. Among the genotypes Pusa Basmati 1 rendered outstanding performance in callus behavior. The treatment combination MS + 2.5 mgl-1 BAP + 0.5 mgl-1 NAA + 1.0 mgl-1 KN gave the highest organogenesis response and regeneration of plantlets. Hardening in mist chamber was recognized as the best method to give the highest per cent of regenerated plant lets.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 56-56
Author(s):  
Michael Thomson

Abstract The precision and ease of use of CRISPR nucleases, such as Cas9 and Cpf1, for plant genome editing has the potential to accelerate a wide range of applications for crop improvement. For upstream research on gene discovery and validation, rapid gene knock-outs can enable testing of single genes and multi-gene families for functional effects. Large chromosomal deletions can test the function of tandem gene arrays and assist with positional cloning of QTLs by helping to narrow down the target region. Nuclease-deactivated Cas9 fusion proteins with transcriptional activators and repressors can be used to up and down-regulate gene expression. Even more promising, gene insertions and allele replacements can provide the opportunity to rapidly test the effects of different alleles at key loci in the same genetic background, providing a more precise alternative to marker-assisted backcrossing. Recently, Texas A&M AgriLife Research has supported the development of a Crop Genome Editing Lab at Texas A&M working towards optimizing a high-throughput gene editing pipeline and providing an efficient and cost-effective gene editing service for research and breeding groups. The lab is using rice as a model to test and optimize new approaches aimed towards overcoming current bottlenecks. For example, a wealth of genomics data from the rice community enables the development of novel approaches to predict which genes and target modifications may be most beneficial for crop improvement, taking advantage of known major genes, high-resolution GWAS data, multiple high-quality reference genomes, transcriptomics data, and resequencing data from the 3,000 Rice Genomes Project. Current projects have now expanded to work across multiple crops to provide breeding and research groups with a rapid gene editing pipeline to test candidate genes in their programs, with the ultimate goal of developing nutritious, high-yielding, stress-tolerant crops for the future.


2020 ◽  
Author(s):  
Koushik Chakraborty ◽  
Akankhya Guru ◽  
Priyanka Jena ◽  
Soham Ray ◽  
Arti Guhey ◽  
...  

Abstract Background and Aims Submergence tolerance in rice is primarily attributed to the action of the SUB1 gene, but other associated traits such as leaf gas film (LGF) thickness, leaf hydrophobicity, porosity and leaf density have been known to aid submergence tolerance in rice. However, association of these traits with SUB1 quantitative trait locus (QTL) has not been demonstrated. In this study, we aim to investigate (1) whether the presence of the SUB1 QTL in the genetic background has any influence on the thickness of the LGF and (ii) whether its removal has any impact on stress perception and submergence tolerance in Sub1 and non-Sub1 rice. Methods We examined 12 genotypes (including both Sub1 and non-Sub1 types) for different leaf traits such as initial LGF thickness, leaf hydrophobicity, tissue porosity and leaf density in order to work out the relatioship of these traits to the SUB1 QTL in rice. Furthermore, we investigated the changes in the gene expression profile and different metabolic processes in selected genotypes in the presence and absence of their LGF to study its impact on stress perception and adaptation. Key Results The initial thickness of the LGF and hydrophobicity seemed to have a highly positive correlation with the presence of the SUB1 QTL in the genetic background of rice; however, other leaf traits such as porosity and density seemed to be independent of it. Artificial removal of the LGF resulted in partial loss of tolerance, showing increased ethylene production and early induction of anoxia-related genes (SUB1A-1, ACS5, Ramy3D and ADH1) which manifested symptoms such as increased stem elongation, faster chlorophyll and starch breakdown, and partial loss of quiescence in SUB1-containing rice genotypes. Stripping of the LGF resulted in early and enhanced induction of SUB1A-1, indicating a quicker perception of stress. Conclusions The presence of SUB1 in the genetic background positively influences surface hydrophobicity and the concomitant LGF thickness of rice. Furthermore, LGF helps in terms of providing better ethylene dissipation and reduced in planta accumulation, owing to the slowing down of ethylene-induced leaf senescence under submergence stress.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 789 ◽  
Author(s):  
Temitope Jekayinoluwa ◽  
Jaindra Nath Tripathi ◽  
George Obiero ◽  
Edward Muge ◽  
Leena Tripathi

Banana and plantain are among the foremost staple food crops providing food and livelihood to over 500 million people in tropical countries. Despite the importance, their production is hampered due to several biotic and abiotic stresses. Plant tissue culture techniques such as somatic embryogenesis and genetic transformation offer a valuable tool for genetic improvement. Identification and quantification of phytochemicals found in banana and plantain are essential in optimizing in vitro activities for crop improvement. Total antioxidants, phenolics, flavonoids, and tannins were quantified in various explants obtained from the field, as well as in vitro plants of banana and plantain cultivars. The result showed genotypic variation in the phytochemicals of selected cultivars. The embryogenic cell suspensions were developed for three farmer-preferred plantain cultivars, Agbagba, Obino l’Ewai, and Orishele, using different MS and B5-based culture media. Both culture media supported the development of friable embryogenic calli (FEC), while MS culture media supported the proliferation of fine cell suspension in liquid culture media. The percentage of FEC generated for Agbagba, Obino l’Ewai, and Orishele were 22 ± 24%, 13 ± 28%, and 9 ± 16%, respectively. Cell suspensions produced from FECs were successfully transformed by Agrobacterium-mediated transformation with reporter gene constructs and regenerated into whole plants.


2018 ◽  
Vol 19 (10) ◽  
pp. 3000 ◽  
Author(s):  
Shouhong Zhu ◽  
Xiuli Yu ◽  
Yanjun Li ◽  
Yuqiang Sun ◽  
Qianhao Zhu ◽  
...  

The clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) gene editing system has been shown to be able to induce highly efficient mutagenesis in the targeted DNA of many plants, including cotton, and has become an important tool for investigation of gene function and crop improvement. Here, we developed a simple and easy to operate CRISPR/Cas9 system and demonstrated its high editing efficiency in cotton by targeting-ALARP, a gene encoding alanine-rich protein that is preferentially expressed in cotton fibers. Based on sequence analysis of the target site in the 10 transgenic cottons containing CRISPR/Cas9, we found that the mutation frequencies of GhALARP-A and GhALARP-D target sites were 71.4–100% and 92.9–100%, respectively. The most common editing event was deletion, but deletion together with large insertion was also observed. Mosaic mutation editing events were detected in most transgenic plants. No off-target mutation event was detected in any the 15 predicted sites analyzed. This study provided mutants for further study of the function of GhALARP in cotton fiber development. Our results further demonstrated the feasibility of use of CRISPR/Cas9 as a targeted mutagenesis tool in cotton, and provided an efficient tool for targeted mutagenesis and functional genomics in cotton.


Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1535 ◽  
Author(s):  
Anastasiya S. Poltavets ◽  
Polina A. Vishnyakova ◽  
Andrey V. Elchaninov ◽  
Gennady T. Sukhikh ◽  
Timur Kh. Fatkhudinov

Macrophages, important cells of innate immunity, are known for their phagocytic activity, capability for antigen presentation, and flexible phenotypes. Macrophages are found in all tissues and therefore represent an attractive therapeutic target for the treatment of diseases of various etiology. Genetic programming of macrophages is an important issue of modern molecular and cellular medicine. The controllable activation of macrophages towards desirable phenotypes in vivo and in vitro will provide effective treatments for a number of inflammatory and proliferative diseases. This review is focused on the methods for specific alteration of gene expression in macrophages, including the controllable promotion of the desired M1 (pro-inflammatory) or M2 (anti-inflammatory) phenotypes in certain pathologies or model systems. Here we review the strategies of target selection, the methods of vector delivery, and the gene editing approaches used for modification of macrophages.


1996 ◽  
Vol 15 (5) ◽  
pp. 322-327 ◽  
Author(s):  
Elumalai Sivamani ◽  
Ping Shen ◽  
Natacha Opalka ◽  
Roger N. Beachy ◽  
Claude M. Fauquet

2017 ◽  
Vol 1 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Joyce Van Eck

Tomato is an effective model plant species because it possesses the qualities necessary for genetic and functional studies, but is also a food crop making what is learned more translatable for crop improvement when compared with other non-food crop models. The availability of genome sequences for many genotypes and amenability to transformation methodologies (Agrobacterium-mediated, direct DNA uptake via protoplasts, biolistics) make tomato the perfect platform to study the application of gene-editing technologies. This review includes information related to tomato transformation methodology, one of the necessary requirements for gene editing, along with the status of site-directed mutagenesis by TALENs (transcription activator-like effector nucleases) and CRISPR/Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated Proteins). In addition to the reports on proof-of-concept experiments to demonstrate the feasibility of gene editing in tomato, there are many reports that show the power of these technologies for modification of traits, such as fruit characteristics (ripening, size, and parthenocarpy), pathogen susceptibility, architecture (plant and inflorescence), and metabolic engineering. Also highlighted in this review are reports on the application of a recent CRISPR technology called base editing that allows the modification of one base pair in a gene sequence and a strategy that takes advantage of a geminivirus replicon for delivery of DNA repair template.


Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1914
Author(s):  
Meenakshi Rajput ◽  
Khushboo Choudhary ◽  
Manish Kumar ◽  
V. Vivekanand ◽  
Aakash Chawade ◽  
...  

With the rapid population growth, there is an urgent need for innovative crop improvement approaches to meet the increasing demand for food. Classical crop improvement approaches involve, however, a backbreaking process that cannot equipoise with increasing crop demand. RNA-based approaches i.e., RNAi-mediated gene regulation and the site-specific nuclease-based CRISPR/Cas9 system for gene editing has made advances in the efficient targeted modification in many crops for the higher yield and resistance to diseases and different stresses. In functional genomics, RNA interference (RNAi) is a propitious gene regulatory approach that plays a significant role in crop improvement by permitting the downregulation of gene expression by small molecules of interfering RNA without affecting the expression of other genes. Gene editing technologies viz. the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (CRISPR/Cas) have appeared prominently as a powerful tool for precise targeted modification of nearly all crops’ genome sequences to generate variation and accelerate breeding efforts. In this regard, the review highlights the diverse roles and applications of RNAi and CRISPR/Cas9 system as powerful technologies to improve agronomically important plants to enhance crop yields and increase tolerance to environmental stress (biotic or abiotic). Ultimately, these technologies can prove to be important in view of global food security and sustainable agriculture.


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