Comparative transcriptome sequencing analysis and functional identification of a NAM-2-like gene in jute (Corchorus capsularis L.)

Abstract

Jute (Corchorus capsularis L.) is one of the most important sources of natural fibre. Drought is among the main factors affecting the production of jute. It is essential for drought tolerance improvement to discover the genes associated with jute development during drought stress. In this study, we analyzed the transcriptome of jute under drought stress and identified new genes involved in drought stress response. In total, 120,219 transcripts with an average length of 764 bp were obtained, these transcripts included 94,246 unigenes (average length, 622 bp). Differentially expressed genes (DEGs) were discovered in drought stress (1329), among which 903 genes showed up-regulated expression, while 426 genes showed down-regulated expression. GO enrichment analyses indicated most of the enriched biological pathways were biosynthesis pathways of organic ring compounds and cellular nitrogen compounds. KEGG enrichment analyses indicated 573 DEGs were involved in 157 metabolic pathways. RT-qPCR experiments indicated that the expression trends were consistent with the results of the high-throughput sequencing. Over-expression of no apical meristem (NAM) -2-like gene increased drought tolerance and knockdown plants were drought sensitive. It has expression peaks after 6 h of drought stress and regulate 3-ketoacyl-CoA synthase gene expression. Yeast-2-Hybrid assays validated the physical interaction between NAM-2-like protein and KCS. The results provide relatively comprehensive information regarding genes and metabolic pathways that lays the foundation for the breeding of drought-resistant varieties, and represent the first identification of NAM-2-like gene and provides new insight into the regulatory network of drought tolerance in Corchorus capsularis L.