Molecular Pathogens 2024, Vol.15, No.5, 227-236 http://microbescipublisher.com/index.php/mp 228 detect and manage effectively. RSD leads to substantial yield losses globally due to its highly contagious nature and the challenges associated with its detection and control (Cia et al., 2018; Zhu et al., 2021). Recent studies have provided insights into the molecular and physiological responses of sugarcane to Lxx infection. Transcriptomic analyses have revealed that sugarcane responds to Lxx infection by altering various metabolic pathways, including photosynthesis, phytohormone biosynthesis, and plant-pathogen interactions. Notably, Lxx infection significantly inhibits photosynthetic processes and down-regulates gibberellin response, contributing to the growth retardation observed in RSD-affected plants. Additionally, the identification of quantitative trait loci (QTL) associated with RSD resistance has opened new avenues for developing RSD-resistant sugarcane varieties through marker-assisted breeding (You et al., 2020). Efficient diagnostic methods are crucial for managing RSD. Techniques such as quantitative PCR on pooled leaf sheath biopsies and the development of mill-based diagnostics using crude cane juice have shown promise in detecting Lxx with high sensitivity, facilitating better disease surveillance and management (Young et al., 2016; Burman et al., 2023). 2.2 Leaf scald disease Leaf Scald Disease, caused by the bacterium Xanthomonas albilineans, is another major bacterial disease affecting sugarcane. This disease is characterized by the appearance of white to yellowish streaks on the leaves, which eventually lead to leaf necrosis and plant death. The pathogen infects the xylem vessels, disrupting water transport and causing wilting and scalding of the leaves (Quecine et al., 2016). The management of Leaf Scald Disease primarily involves the use of disease-free planting material, crop rotation, and the application of bactericides. Breeding for resistant varieties is also a key strategy in controlling this disease. However, the development of resistant varieties is challenging due to the complex nature of the disease and the genetic variability of the pathogen. 2.3 Gumming disease Gumming Disease, caused by the bacterium Xanthomonas vasculorum, is a significant threat to sugarcane production. This disease is characterized by the exudation of a gummy substance from the infected tissues, leading to the formation of lesions and cankers on the stalks and leaves. The pathogen infects the vascular system, causing wilting, stunted growth, and eventual plant death. Control measures for Gumming Disease include the use of disease-free planting material, sanitation practices to prevent the spread of the pathogen, and the application of bactericides (Chakraborty et al., 2023). Breeding for resistant varieties is also an important strategy, although it is complicated by the genetic diversity of the pathogen and the polyploid nature of sugarcane. 3 Mechanisms of Pathogenicity in Sugarcane Bacterial Diseases 3.1 Virulence factors in bacterial pathogens Virulence factors are critical components that enable bacterial pathogens to infect and cause disease in sugarcane. These factors include enzymes, toxins, and other molecules that facilitate the invasion and colonization of host tissues. For instance, Acidovorax avenae subsp. avenae, the causal agent of red stripe disease, exhibits various virulence factors such as proteases, amylases, and endoglucanases, which are essential for breaking down plant cell walls and facilitating infection (Bertani et al., 2023). Similarly, Sporisorium scitamineum, responsible for sugarcane smut, produces plant cell wall degrading enzymes (PCWDEs) like chitinase and laccase, which are crucial for tissue colonization and successful pathogen ingress (Nalayeni et al., 2021). The interplay among these virulence factors is complex and often involves multiple genes and pathways, highlighting the multifaceted nature of bacterial pathogenicity in sugarcane (Zhao et al., 2022). 3.2 Host-pathogen interactions The interaction between sugarcane and bacterial pathogens is a dynamic process involving both the pathogen's virulence mechanisms and the host's defense responses. Xanthomonas albilineans, which causes leaf scald, modulates the host's reactive oxygen species (ROS) homeostasis and salicylic acid (SA) pathway to establish
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