Genomics and Applied Biology 2024, Vol.15, No.6, 285-295 http://bioscipublisher.com/index.php/gab 288 3.3 Molecular mechanisms enhancing photosynthetic efficiency Several molecular mechanisms have been identified that enhance photosynthetic efficiency in sweet potato. The overexpression of antioxidant enzyme genes, such as Cu/Zn SOD and APX, has been shown to maintain higher photosynthetic capacity under drought stress by improving light energy conversion efficiency and reducing photorespiration (Lu et al., 2015). Additionally, genetic variations in starch biosynthesis and sucrose metabolism genes, such as IbAGPb3 and IbGBSS1-1, contribute to the regulation of starch properties, which are essential for efficient photosynthesis and energy storage (Zhang et al., 2020). The vacuolar invertase gene Ibβfruct2-1 also plays a role in regulating starch and glucose content, further influencing photosynthetic efficiency (Zhang et al., 2023). The genetic regulation of photosynthesis in sweet potato is a complex process involving multiple genes, transcription factors, and signaling pathways. Key regulatory genes such as IbVP1 and IbMIPS1, along with transcription factors like IbNAC43 and IbBBX29, play significant roles in modulating photosynthetic efficiency. Signal transduction pathways, including those mediated by PI and ABA, as well as the influence of photoreceptors and hormones, are crucial for maintaining photosynthesis under stress conditions. Understanding these molecular mechanisms provides valuable insights for improving photosynthetic efficiency and crop yield in sweet potato. 4 Recent Advances in Genetic Manipulation for Enhanced Photosynthesis 4.1 Approaches to enhance photosynthetic efficiency Recent advancements in genome-editing technologies, particularly CRISPR/Cas9, have revolutionized plant genetic engineering. CRISPR/Cas9 allows for precise, targeted modifications in plant genomes, which can be used to enhance photosynthetic efficiency. This technology has been successfully applied to various crops, including sweet potato, to improve traits such as starch quality and resistance to biotic and abiotic stresses (Figure 2) (Chen et al., 2019; Wang et al., 2019; Ahmad et al., 2022). The CRISPR/Cas9 system is favored for its simplicity, high efficiency, and cost-effectiveness compared to earlier genome-editing tools like zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) (Wang et al., 2015; Razzaq et al., 2019; Zhou et al., 2023). Additionally, the development of base-editing tools and DNA-free delivery systems has further enhanced the precision and applicability of CRISPR/Cas9 in crop improvement. Traditional breeding methods have long been used to improve crop traits, but they are often time-consuming and less precise. In contrast, molecular breeding techniques, including CRISPR/Cas9, offer a more targeted approach to genetic improvement. Molecular breeding can rapidly introduce desirable traits by directly modifying specific genes, bypassing the lengthy process of crossbreeding and selection (Razzaq et al., 2019; Wang et al., 2022). For instance, CRISPR/Cas9 has been used to create transgene-free, genome-edited plants with enhanced traits, such as improved starch quality in sweet potato and increased resistance to environmental stresses in other crops (Wang et al., 2019; Tussipkan and Manabayeva, 2021; Ahmad et al., 2022). These advancements highlight the potential of molecular breeding to complement and enhance traditional breeding efforts. 4.2 Genetic engineering of photosynthetic pathways in other crops: lessons for sweet potato The application of genetic engineering to enhance photosynthetic pathways has been extensively studied in various crops, providing valuable insights for sweet potato improvement. For example, CRISPR/Cas9 has been used to modify genes involved in starch biosynthesis in potato, leading to improved tuber quality and yield (Wang et al., 2015; Ahmad et al., 2022). These studies demonstrate the potential of genome editing to enhance photosynthetic efficiency and overall crop performance. By leveraging these lessons, similar strategies can be applied to sweet potato to optimize its photosynthetic pathways and improve its productivity and nutritional value (Wang et al., 2019; Tussipkan and Manabayeva, 2021; Wang et al., 2022). 4.3 Potential challenges and risks in genetic modification for photosynthetic efficiency While genetic modification holds great promise for enhancing photosynthetic efficiency, it also presents several challenges and risks. One major concern is the off-target effects of genome editing, which can lead to unintended genetic changes and potential ecological impacts (Chen et al., 2019; Razzaq et al., 2019; Zhou et al., 2023).
RkJQdWJsaXNoZXIy MjQ4ODYzMg==