Molecular Pathogens 2024, Vol.15, No.5, 237-245 http://microbescipublisher.com/index.php/mp 243 promising results in conferring resistance to multiple strains of Xanthomonas oryzae pv. oryzae (Xoo) (Zeng et al., 2015; Wang et al., 2021; Chen et al., 2021). Further exploration into the genetic diversity of wild rice species and related genera, such as Leersia, could uncover novel resistance genes that can be integrated into cultivated rice varieties (Kumar et al., 2012; Wang et al., 2021). Additionally, the identification of natural variations in the promoter regions of susceptibility genes, like OsSWEET13 and OsSWEET14, can expand the range of resistance against Xoo (Zaka et al., 2018). Comprehensive genomic and transcriptomic analyses can also reveal new candidate genes and pathways involved in plant immunity, which can be targeted for developing resistant cultivars (Bakade et al., 2021). 7.2 Application prospects of emerging gene editing technologies Emerging gene editing technologies, such as CRISPR/Cas9, offer significant potential for engineering disease resistance in rice. These technologies can be employed to precisely modify resistance genes or susceptibility gene promoters to enhance resistance against Xoo. For instance, CRISPR/Cas9 can be used to introduce specific mutations in the effector binding elements (EBEs) of susceptibility genes, thereby preventing the activation of these genes by bacterial effectors (Zaka et al., 2018). Additionally, gene editing can facilitate the pyramiding of multiple resistance genes into a single cultivar, providing a robust and durable defense against a wide range of Xoo strains (Kim and Reinke, 2019). The ability to rapidly and accurately edit the rice genome holds promise for accelerating the development of disease-resistant rice varieties. 7.3 The role of interdisciplinary collaboration in genetic engineering disease resistance research Interdisciplinary collaboration is crucial for advancing genetic engineering research aimed at disease resistance. Integrating expertise from molecular biology, genomics, bioinformatics, and plant pathology can lead to a more comprehensive understanding of the rice-Xoo interaction and the mechanisms underlying disease resistance (Niño-Liu et al., 2006; Jiang et al., 2020). Collaborative efforts can also enhance the development and deployment of advanced genetic tools and technologies, such as high-throughput screening methods and gene editing platforms. Furthermore, partnerships between academic institutions, research organizations, and agricultural industries can facilitate the translation of research findings into practical applications, ensuring that newly developed resistant rice varieties are effectively integrated into breeding programs and agricultural practices (Jiang et al., 2020). 8 Summary and Outlook This study presents significant advancements in the genetic engineering of rice for durable resistance against Xanthomonas oryzae pv. oryzae (Xoo), the pathogen responsible for bacterial blight. The primary contribution is the development of the modified Xa10 gene, designated as Xa10 (E5), which incorporates an EBE-amended promoter with five tandemly arranged EBEs. This modification allows the gene to respond specifically to corresponding virulent or avirulent TAL effectors, providing broad-spectrum and durable resistance to Xoo across various developmental stages of rice. Additionally, the study highlights the successful generation of stable transgenic rice lines containing Xa10 (E5) in the Nipponbare cultivar, which demonstrated resistance to 27 out of 28 Xoo strains collected from 11 countries. This work builds on previous findings, such as the cloning of the Xa21 gene, which also confers multi-isolate resistance to Xoo, and the identification of the Xa7 gene, which provides durable resistance through a unique promoter trap mechanism. Genetic engineering strategies hold immense potential for enhancing resistance to bacterial blight in rice, a critical crop for global food security. The development of genes like Xa10 (E5) and Xa21 demonstrates the feasibility of creating rice varieties with broad-spectrum and durable resistance to multiple Xoo strains. These advancements are crucial in the context of evolving pathogen virulence and climate change, which necessitate the continuous development of new resistance genes and gene-deployment strategies. The identification of natural variations in the promoters of susceptibility genes, such as OsSWEET13 and OsSWEET14, further expands the range of resistance and offers additional avenues for genetic improvement. The integration of these genetic engineering approaches with traditional breeding methods can lead to the development of rice varieties that are not only resistant to bacterial blight but also adaptable to diverse environmental conditions, thereby ensuring sustainable rice production.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==