CRISPR-Cas systems as antimicrobial agents for agri-food pathogens

name of first author & corresponding author is: Gacem, Mohamed Amine (not Amine, Gacem Mohamed as indicated at publisher's page)The CRISPR-Cas (clustered regularly interspaced short palindromic repeat-CRISPR-associated sequences) systems identified in microorganisms are very diverse in their functional organization and mechanism. They participate in the illustration of the development of the strain that carries them over time. The reason is that each time an exogenous genetic fragment is encountered, a spacer is acquired and then inserted into the CRISPR array. These spacers can provide very important historical information on external aggressors, their ecology, and geography. This complex arrangement has a dynamic protection and defense capacity against exogenous genetic elements, which gives the bacterial cell better protection. On the genomic level, the understanding of its functional mechanism is a key factor in its exploitation as a molecular biology and genome editing tool. This chapter aims at clarifying the applications of the CRISPR/Cas system in the preservation and security of crops and food against viral, fungal, and bacterial alterations. © 2021 Elsevier Inc. All rights reserved.

RNAi-based system a new tool for insects’ control

One of the molecular devices practised recently has been the fusion of RNA interference (RNAi) into some agricultural products. It is a definite genetic controlling system recognized in eukaryotes. Through this system, certain exogenous pathogens are neutralized by deactivating the expression of target genes. The decisive factor for the progress of this gene defence machinery is the double-stranded RNA (dsRNA). The effectiveness and specificity of the RNAi tool in gene silencing have been approved with great precision in small-scale guide tests. The development of this molecular tool as bioinsecticides has started to attract the biotechnology industries. Once the safety and certainty actions respecting the regulatory framework are established by researchers and biotechnology industries for crop protection, for example, sustainability and particularity of defence, develop new resistant cultivars against plant pests, and removal of all unexpected effects on the environment, genetically modified crops incorporating dsRNA can be marketed. The current chapter discusses the RNAi tool and its role in protecting crops from insect pest attacks, dsRNA transfer methods in plant cells, and critical points affecting the achievement of the molecular tool. Finally, some environmental risks identified in the small-scale guide tests are discussed