Transcriptome Profile Analysis of Twisted Leaf Disease Response in Susceptible Sugarcane with Narenga porphyrocoma Genetic Background

Sugarcane is an important industrial crop with a high sugar yield that has become a leading energy crop worldwide. It is widely cultivated in tropical and subtropical regions. Various diseases beset the cultivation of sugarcane. The molecular study of disease resistance in sugarcane is limited by its complicated genome. In our study, RNA-seq was employed to detect the mechanism of twisted leaf disease tolerance in modern cultivar sugarcane, which derived from Narenga porphyrocoma. We completed high-throughput transcriptomic sequencing of 12 samples, including three stages of a susceptible (NSBC1_T H3-8) and an unsusceptible cultivar (NSBC1_CK H-19) with two biological repeats, respectively. Using the Saccharum spontaneum genome as reference, the average mapping ratio of the clean data was over 70%. Among the differentially expressed genes between H3-8 and H3-19, we focused on the analysis of hormone pathways and resistance (R) genes. The results showed that twisted leaf disease triggers hormone networks and around 40% of R genes conditioned lower expression in the susceptible cultivar. One of the possible reasons for H3-8 being susceptible to twisted leaf disease might be the null/retarded response of R genes, especially in pre-onset stage (46% down-regulated) of pathogens infection.