Transcriptomic characterization and potential marker development of contrasting sugarcane cultivars

Sugarcane (Saccharum officinarum L.) is an important crop for sugar production and bioenergy worldwide. In this study, we performed transcriptome sequencing for six contrasting sugarcane genotypes involved in leaf abscission, tolerance to pokkah boeng disease and drought stress. More than 465 million high-quality reads were generated, which were de novo assembled into 93,115 unigenes. Based on a similarity search, 43,526 (46.74%) unigenes were annotated against at least one of the public databases. Functional classification analyses showed that these unigenes are involved in a wide range of metabolic pathways. Comparative transcriptome analysis revealed that many unigenes involved in response to abscisic acid and ethylene were up-regulated in the easy leaf abscission genotype, and unigenes associated with response to jasmonic acid and salicylic acid were up-regulated in response to the pokkah boeng disease in the tolerance genotype. Moreover, unigenes related to peroxidase, antioxidant activity and signal transduction were up-regulated in response to drought stress in the tolerant genotype. Finally, we identified a number of putative markers, including 8,630 simple sequence repeats (SSRs) and 442,152 single-nucleotide polymorphisms (SNPs). Our data will be important resources for future gene discovery, molecular marker development, and genome studies in sugarcane.