부산대학교 도서관

Ratoon stunting disease (RSD) caused by bacterium Leifsoniaxyli subsp. xyli (Lxx) is a devastating disease of sugarcane over a large part of the world. Genetic improvement for RSD‐resistant varieties is considered the most effective method to control the disease. However, genetic improvement of sugarcane is hindered by the limited information about the molecular mechanisms underlying Lxx pathogenicity and defence responses in sugarcane. In this study, genome‐wide gene expression profiling was used to compare RSD‐resistant (CP72‐2086) and RSD‐susceptible (GT11) genotypes at different infection time points in order to identify the candidate regulators for RSD resistance. A total of 14,494 differentially expressed genes (DEGs) were identified, indicating that dramatic changes had occurred in gene expression upon Lxx infection, especially in the susceptible genotype. Enrichment analysis showed that a large number of genes related to plant hormone signal transduction, phenylalanine metabolism, phenylpropanoid biosynthesis and starch and sucrose metabolism was responsible for sugarcane response to Lxx infection. Plant hormone signalling pathway genes were significantly differentially expressed at the early infection stage between the two genotypes. The resistant genotype chose the jasmonic acid‐ and ethylene‐dependent host‐defence pathways to resist Lxx infection, whereas the susceptible genotype preferred the salicylic acid‐dependent host‐defence pathways. These findings help unravel the molecular mechanisms of sugarcane plant–Lxx interactions and may pave the way for sugarcane breeding for disease resistance. [ABSTRACT FROM AUTHOR]