Genome Editing In Plant—Targeted Modification of the Genome Contributes to the Future Prospects of Agricultural Development
|18.2.2021||Posted by tactical33 under Advertising & Marketing|
By transferring genes or genetic elements with known functions to superior crop varieties, genetically modified (GM) crops with beneficial properties can be produced. Despite the promise that GM crops can contribute to global food security, the use of GM crops is affected by largely unproven health and environmental safety issues. The government regulatory framework aimed at maintaining human and environmental biosafety has created a huge cost barrier to the rapid and widespread adoption of new genetically modified properties. As a result, the advantages of transgenic properties have been limited to a few cultivated crops.
Genome editing is defined as a collection of advanced molecular biology techniques that facilitate precise, efficient and targeted modification of genome sites. The risks involved in changing the genome through the use of genome editing techniques are significantly lower than those associated with genetically modified crops, because most edits only change a few nucleotides, and the resulting changes are no different from those found in natural populations. Once the genome editing agent is isolated, it is impossible to distinguish between “naturally occurring” mutations and gene editing. Therefore, introducing genome editing into modern breeding programs should help improve crops quickly and accurately.
Genome editing technology has shown great potential in agriculture, but it is still limited by low HR efficiency, off-target effects, restricted protospacer adjacent motif (PAM) sequence, and other issues. Fortunately, novel innovations are constantly being added to the genome editing toolkit to address these limitations. In plants, cellular processes are usually regulated by complex genetic networks. The manipulation of agronomic traits depends on the precise engineering of complex metabolic pathways, which requires the coordinated expression of multiple genes. Therefore, molecular tools that can manipulate multiple genes at the same time have important value in both basic research and practical applications.
Now that the complete genomes of many crops have been sequenced, the challenge in the post-genomic era is to systematically analyze the functions of all crop genes, because most of the genes sequenced so far have unknown functions and may control important agronomic traits. Gene knockout is a common method to identify gene function. Therefore, a large-scale mutant library at the whole genome level is of great value for functional genomics and crop improvement.
Recently, CRISPR/Cas9 technology has been used for crop improvement by changing the cis-regulation of quantitative trait loci. Differing from applications that mainly focus on changing DNA sequences, genome editing has a role in gene regulation at the transcriptional level and can be used to reveal many non-classical RNA functions related to crop improvement. Since most non-coding transcripts are nuclear and lack an open reading frame, genome editing that directly regulates transcription is most suitable for interrogating the function of such RNAs.
In the past few decades, traditional breeding, which relies on plant populations with sufficient variability, has made great contributions to agriculture. However, this variability mainly comes from spontaneous mutations or mutations induced by chemical mutagens or physical irradiation. Such mutations are usually rare and occur randomly. In addition, superior varieties may not show many types of mutations, so time-consuming and laborious breeding procedures are required to introduce ideal alleles into superior crops. On the contrary, genome editing as an advanced molecular biology technology can produce precise targets in any crop.