Transcriptome Reveals Differentially Expressed Genes in Saccharum spontaneum GX83-10 Leaf Under Drought Stress

Abstract

Saccharum spontaneum is the most important and widely used wild germplasm in sugarcane resistance breeding, which can improve sugarcane resistance and ratoon capacity. In order to further exploit and utilize the resistance genes in S. spontaneum, we used a new generation of sequencing technology Illumina HiSeq high-throughput platform to analyze the expression profile of transcriptome genes in S. spontaneum GX83-10 leaves under normal watering (SS_CK) and drought stress (SS_T). The sequencing data were assembled by de novo, and functional annotation, differential gene screening and enrichment analysis were done. The results showed that 54499640 and 56440692 clean reads were obtained from the drought stress group and the control group, respectively. A total of 88941 unigenes and 1325 significantly differentially expressed genes (DEGs) were obtained in this study. The 125 functional gene groups were enriched by GO enrichment analysis. Five metabolic pathways were obtained by KEGG enrichment analysis, namely ascorbate and aldarate metabolism, plant hormone signal transduction, carotenoid biosynthesis, starch and sucrose metabolism, and phenylpropanoid biosynthesis. Seven significantly up-regulated genes were selected to conduct qRT-PCR analysis, and the results confirmed that all the seven genes were significantly up-regulated at varying degrees under drought stress. This study revealed the molecular mechanism of S. spontaneum leaf in response to drought stress and provided a reference for researches on related key genes which would be beneficial to breed new drought-resistant sugarcane varieties.