Rice Genomics and Genetics 2024, Vol.15, No.4, 190-202 http://cropscipublisher.com/index.php/rgg 198 to revolutionize hybrid rice breeding, including gene editing and synthetic biology, the integration of multi-omics strategies, and the role of policy and regulatory frameworks. 6.1 Emerging trends and innovations CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology has revolutionized genetic engineering, providing a precise and efficient tool for editing plant genomes. In rice breeding, CRISPR/Cas9 and other gene-editing technologies offer unprecedented opportunities to enhance hybrid vigor by targeting specific genes associated with yield, stress resistance, and other desirable traits. Gene editing can be used to create novel genetic variations that enhance heterosis. Zhang et al. (2018) have successfully used CRISPR/Cas9 to knock out genes that negatively affect yield and to introduce beneficial alleles that improve agronomic performance. This technology also allows for the rapid development of hybrids with improved resistance to biotic and abiotic stresses, such as pests, diseases, drought, and salinity (Figure 2). Figure 2 The rapid domestication of NSRPs using precise gene editing (Adopted from Zhang et al., 2018) Image caption: After the reference genome (or assembled transcriptome) of an NSRP is generated, candidate domestication genes can be identified based on their orthologous relationship with domestication genes in the closest crop relative. A CRISPR-Cas9 vector targeting multiple candidate domestication genes can then be generated. CRISPR-Cas9 can be delivered into the plants in at least two ways: (1) the plasmid can be delivered into calli (for example, through particle bombardment), with co-delivery of a plasmid for overexpression of Bbm and Wus2 orthologous genes to facilitate plant regeneration; or (2) the plasmid DNA or Cas9-sgRNA ribonucleoprotein complex can be mixed with magnetic nanoparticles (MNPs), and the coated MNPs can then be drawn by a strong magnetic field into pollen through pollen apertures. The magnetofected pollen is used to pollinate emasculated flowers to generate gene-edited plants. Edited NSRPs with desired traits can then be selected in the field or glasshouse (Adapted from Zhang et al., 2018) One of the key advantages of CRISPR is its ability to make precise modifications without introducing foreign DNA, which can address regulatory and consumer concerns associated with genetically modified organisms (GMOs). This makes CRISPR-edited hybrids more likely to gain acceptance and regulatory approval, paving the way for their adoption in agricultural practices. Synthetic biology, which involves the design and construction of new biological parts, devices, and systems, offers exciting possibilities for hybrid rice breeding. This interdisciplinary field combines principles from biology, engineering, and computer science to create synthetic gene networks and metabolic pathways that can enhance plant traits. In rice, synthetic biology can be used to engineer metabolic pathways that enhance photosynthesis efficiency, nutrient uptake, and stress tolerance. Ermakova et al. (2019) exploring the synthesis of C4 photosynthetic
RkJQdWJsaXNoZXIy MjQ4ODYzNA==