Comparative analysis reveals changes in transcriptomes of sugarcane upon infection by Leifsoniaxyli subsp. xyli

Abstract

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.

Comparative Transcriptome Profiling of Resistant and Susceptible Sugarcane Cultivars in Response to Infection by Xanthomonas albilineans

“…In this study, we proposed that ABA signal transduction pathway may play negative or unimportant role on sugarcane resistance to X. albilineans, as validated by the upregulation of PYL (a receptor complex of ABA) in susceptible cultivar ROC20 but no significant change in the transcripts expression of SNRK2 gene in two cultivars. Recently, a similar result presented by Fu et al (2019) showed that the susceptible genotype accumulated higher level ABA receptor PYR/PYL than the resistant genotype at 24 hpi under Lxx infection [24]. An additional case by Su et al (2016) demonstrated that a protein phosphates 2C (PP2C, a negative regulator) that was responsible for ABA signaling was upregulated in smut-susceptible cultivar ROC22, but remained unchanged in smut-resistance cultivar Yacheng05-179, suggesting the ABA pathway was not involved or at least unimportant in the defense response of sugarcane to S. scitamineum [51].…”

“…avenae causing red stripe disease [22] and Leifsonia xyli subsp. xyli (Lxx) causing ratoon stunting disease [23,24]. These findings showed that many common genes and the pathways they are involved with constitute important clues for further investigation of sugarcane-pathogen interactions.…”

Molecular mechanism of endophytic bacteria DX120E regulating polyamine metabolism and promoting plant growth in sugarcane

“…Several transcriptomic studies have revealed the functions of endophytic bacteria during symbiosis between plants and phytopathogens ( Ling et al., 2018 ; Fu et al., 2019 ; Zhu et al., 2021 ). These promising results suggest that dual RNA-seq analyses could be used to understand the physiological and molecular mechanism interactions between novel PGPB and crops.…”