CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a revolutionary gene editing tool that allows scientists to make precise changes to the DNA of an organism with remarkable ease and accuracy. By using an enzyme called Cas9 guided by a small RNA molecule, CRISPR enables the targeting and modification of specific genes, opening up new possibilities for research and applications in fields such as medicine, agriculture, and biotechnology.
According to a review of gene editing techniques, the CRISPR/Cas method has the potential to be a “savior” for rice crops facing challenges from climate change and high food demand.
A study on gene editing shows CRISPR/Cas may be the answer to saving rice crops facing challenges from climate change and increased food demand.
The study, published in CABI Reviews, highlights that rice, a cereal consumed by billions worldwide, is facing production and quality challenges due to climate stressors. Despite rice providing sustenance for three billion people, it is being impacted by both biotic and abiotic stress caused by the changing climate.
Dr. Antonio Costa de Oliveira, lead author of the Federal University of Pelotas, Brazil, and a team of fellow scientists found that the CRISPR/Cas tool was efficient in gene editing in studies related to yield, tolerance to biotic and abiotic stresses, and rice grain quality.
A scientist inspects rice in China. Credit: CABI
However, the review, which sought to describe the different gene editing techniques and their respective applications in rice breeding, argues that the impact of the CRISPR/Cas approach in breeding programs depends upon the cultivation of the edited plants on a large scale in the field.
Dr. Costa de Oliveira said, “The development of new, higher-yielding cultivars is necessary to ensure global food security.
“Although great progress has already been achieved by conventional breeding, biotechnological tools, such as transgenics and genome editing, can aid in meeting future demands.
“Gene editing is characterized by cutting and modifying target genes. Among the genome editing techniques, CRISPR/Cas has been proposed because of its ease of manipulation.
“Variants such as multiple Cas proteins, base editing, and prime editing, which aim to increase editing efficiency have also been proposed. Edited plants are also more accepted because they are transgene-free.”
The study outlines that a 50% increase in the current consumption of rice is projected for 2050 – which would mean a demand as high as 1.125 billion tonnes.
But the occurrence of biotic stresses (diseases – viruses, bacteria, fungi, nematodes, pests, and weeds) coupled with abiotic stresses (drought, submergence, salinity, heat, cold and heavy metals) is a limiting factor for rice production.
Climate change also influences the frequency, intensity, and duration of these stresses, the scientists say. Therefore, it is necessary to develop new rice cultivars with tolerance to stress and higher yield potential, since the expansion of the cultivated area is limited.
Dr. Costa de Oliveira added, “The high potential of CRISPR/Cas9 editing, for instance, has aided in the development of broad-spectrum resistance against bacteria, fungi, and viruses by silencing susceptibility genes and the insertion of resistance genes.
“In this sense, CRISPR/Cas9-mediated genome editing has made it possible to introduce mutations in three promoters of the SWEET gene that resulted in rice lines with broad-spectrum resistance to Xanthomonas oryzae pv. Oryzae.”
The researchers conclude by stating that although conventional breeding has been decisive so far, there is still a long way to go in order to meet future demands and face the challenges of rice cultivation.
“plants improved from genome editing and conventional breeding are similar in terms of risks to the environment and human health, which are practically non-existent,” Dr. Costa de Oliveira said. “Therefore, it is expected that edited plants, in addition to meeting the demands, have good acceptance among consumers.”
Reference: “Genome editing in rice: New paths for an old crop” by Valeria Oliveira Nizolli, Victoria Freitas de Oliveira, Luciano Carlos da Maia, Camila Pegoraro and Antonio Costa de Oliveira, 3 March 2023, CABI Reviews.
DOI: 10.1079/cabireviews.2023.0008
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