Molecular Microbiology Research 2024, Vol.14, No.6, 277-289 http://microbescipublisher.com/index.php/mmr 280 Figure 2 Transcriptional profile analysis of a time-course of plant infection by the rice blast fungus M. oryzae (Adopted from Yan et al., 2022) Image caption: The figure overall shows how the rice blast fungus progresses in rice tissue over time, visualizing the infection process, the impact on plant tissue, and quantifying the extent of fungal spread or damage under different conditions. The data seem to indicate that certain treatments or genetic factors could mitigate or exacerbate the effects of the fungus, providing insights into possible control strategies (Adopted from Yan et al., 2022) 3.2 Quantitative trait Loci (QTLs) for blast resistance Quantitative Trait Loci (QTLs) are genomic regions that contribute to the variation in complex traits such as disease resistance. In rice, approximately 350 QTLs associated with blast resistance have been identified and mapped, providing a comprehensive resource for understanding the genetic basis of partial resistance (Ballini et al., 2008). For example, a study on the japonica rice cultivar Moroberekan identified ten chromosomal segments associated with partial resistance to blast, illustrating the complex genetic architecture underlying durable resistance. Another study on upland rice identified a major QTL for leaf blast resistance on chromosome 11, which was further fine-mapped to a 108.9-kb genomic region, highlighting the potential for marker-assisted selection in breeding programs (Tan et al., 2022). Most of the cloned R-QTL were associated with leaf rice blast resistance at the seedling stage, whereas only a few genes such as Pb1, Pi25, Pi64 andPi68 were resistant to spike rice blast. While the majority of R-QTL provided race-specific resistance, a few R-QTL including Pi2, Pi54, Pi9, Pigm, Pizt and Pi54 provided broad-spectrum resistance (Shanika et al., 2024). Non-race-specific resistance has been more effective in controlling crop diseases than race-specific resistance because of its broad spectrum and durability. 3.3 Molecular mechanisms of blast resistance In the long-term evolution of rice, two natural immune systems develop when rice is infested with rice blast fungus (Ting et al., 2021). These include pathogenic factor-related molecular pattern-triggered immunity (Pattern-triggered Immunity, PTI) and resistance protein (R protein)-mediated effector protein-triggered immunity (Effector-triggered Immunity, ETI). Both immune systems are capable of inducing rice to develop rice blast
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