CRISPR-Cas genetic engineering of plants holds tremendous potential for providing food security, battling biotic and abiotic crop stresses caused by climate change, and for environmental remediation and sustainability. Since the discovery of CRISPR-Cas technology, its usefulness has been demonstrated widely, including for genome editing in plants. Despite the revolutionary nature of genome-editing tools and the notable progress that these tools have enabled in plant genetic engineering, there remain many challenges for CRISPR applications in plant biotechnology. Nanomaterials could address some of the most critical challenges of CRISPR genome editing in plants through improvements in cargo delivery, species independence, germline transformation and gene editing efficiency. This Perspective identifies major barriers preventing CRISPR-mediated plant genetic engineering from reaching its full potential, and discusses ways that nanoparticle technologies can lower or eliminate these barriers. We also describe advances that are needed in nanotechnology to facilitate and accelerate plant genome editing. Timely advancement of the application of CRISPR technologies in plant engineering is crucial for our ability to feed and sustain the growing human population under a changing global climate.

Nanotechnology to advance CRISPR-Cas genetic engineering of plants.

Viruses are obligate parasites that exist in an inactive state until they enter the host body. Upon entry, viruses become active and start replicating by using the host cell machinery. All plant viruses can augment their transmission, thus powering their detrimental effects on the host plant. To diminish infection and diseases caused by viruses, the plant has a defence mechanism known as pathogenesis-related biochemicals, which are metabolites and proteins. Proteins that ultimately prevent pathogenic diseases are called R proteins. Several plant R genes (that confirm resistance) and avirulence protein (Avr) (pathogen Avr gene-encoded proteins [effector/elicitor proteins involved in pathogenicity]) molecules have been identified. The recognition of such a factor results in the plant defence mechanism. During plant viral infection, the replication and expression of a viral molecule lead to a series of a hypersensitive response (HR) and affect the host plant's immunity (pathogen-associated molecular pattern-triggered immunity and effector-triggered immunity). Avr protein renders the host RNA silencing mechanism and its innate immunity, chiefly known as silencing suppressors towards the plant defensive machinery. This is a strong reply to the plant defensive machinery by harmful plant viruses. In this review, we describe the plant pathogen resistance protein and how these proteins regulate host immunity during plant-virus interactions. Furthermore, we have discussed regarding ribosome-inactivating proteins, ubiquitin proteasome system, translation repression (nuclear shuttle protein interacting kinase 1), DNA methylation, dominant resistance genes, and autophagy-mediated protein degradation, which are crucial in antiviral defences.

Host Plant Strategies to Combat Against Viruses Effector Proteins

The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas gene editing technology has opened a new era of genome interrogation and genome engineering because of its ease operation and high efficiency. An increasing number of plant species have been subjected to site-directed gene editing through this technology. However, the application of CRISPR-Cas technology to medicinal plants is still in the early stages. Here, we review the research history, structural characteristics, working mechanism and the latest derivatives of CRISPR-Cas technology, and discussed their application in medicinal plants for the first time. Furthermore, we creatively put forward the development direction of CRISPR technology applied to medicinal plant gene editing. The aim is to provide a reference for the application of this technology to genome functional studies, synthetic biology, genetic improvement, and germplasm innovation of medicinal plants. CRISPR-Cas is expected to revolutionize medicinal plant biotechnology in the near future. 

/pdf/crispr-cas-gene-editing-technology-and-its-application-3t433igy.pdf

CRISPR-Cas gene editing technology and its application prospect in medicinal plants

The search for technologies for crop improvement has been a continuous practice to address the food insecurity to the growing human population with an ever-decreasing arable land and dynamic climate change around the world. Considering the potential technologies for crop improvement could close the rooms of poverty in developing countries in particular and around the globe at large. This review aimed to assess the site-directed mutation creation methods and show the potential tools for future crop improvement programs. Site-directed mutagenesis was found to be an efficient process to create targeted mutation on cereal crops, horticultural crops, oilseed crops, and others. Agronomic traits such as yield, quality, and stress tolerance have been improved using site-directed mutagenesis. Besides, selectable marker elimination was also reported from transgenic crops by targeted mutation. Most of the reports on site-directed mutagenesis is focusing on cereal crops (58.339%) followed by horticultural crops (22.92%). Among the four mutagenic tools that have been reported, the CRISPR/Ca9 technology was found to be frequently used (66.67%) followed by TALENs. This tool is potential, since it is efficient in creating targeted mutagenesis and less likely off-target effect, so it is repeatedly used in different research works. TALENs were used usually to knockout genes with bad traits. Moreover, the mutation created by mutagenic tools was found to be efficient, and the mutated traits proved to be heritable to generations. Hence, site-directed mutagenesis by the CRISPR/Cas9 system is advisable for agricultural development, thereby ensuring food sustainability around the world.

/pdf/the-potential-applications-of-site-directed-mutagenesis-for-tm255wuqr5.pdf

The potential applications of site-directed mutagenesis for crop improvement: a review

The search for technologies for crop improvement has been a continuous practice to address the food insecurity to the growing human population with an ever decreasing arable land and dynamic climate change around the world. Considering the potential technologies for crop improvement could close the rooms of poverty in developing countries in particular and around the globe at large. This review aimed to assess the site-directed mutation creation methods and to show the potential tools for future crop improvement programs. Site-directed mutagenesis was found to be an efficient process to create targeted mutation on cereal crops, horticultural crops, oilseed crops, and others. Agronomic traits such as yield, quality, and stress tolerance have been improved using site-directed mutagenesis. Besides, selectable marker elimination was also reported from transgenic crops by targeted mutation. Most of the reports on site-directed mutagenesis is focusing on cereal crops (58.339%) followed by horticultural crops (22.92%). Among the four mutagenic tools that have been reported, the CRISPR/Ca9 technology was found to be frequently used (66.67%) followed by TALENs. This tool is potential since it is efficient in creating targeted mutagenesis and less likely off-target effect, so it is repeatedly used in different research works. TALENs were used usually to knockout genes with bad traits. Moreover, the mutation created by mutagenic tools found to be efficient, and the mutated traits proved as it was heritable to generations. Hence, site-directed mutagenesis by the CRISPR/Cas9 system is advisable for agricultural development thereby ensuring food sustainability around the world.

/pdf/the-potential-applications-of-site-directed-mutagenesis-for-3wm449ugpy.pdf

Monika Gupta

Papers

Trends of CRISPR technology development and deployment into Agricultural Production-Consumption Systems