Mechanistic insights into longan (Dimocarpous longan Lour.) transcriptome for physiological characterization for defensive genes and differential gene expression analysis with longan embryogenic callus transcriptome

Abstract

Longan is one of several subtropical and climateric fruit tree of South East Asia having economic and medicinal importance. To understand the mechanism behind altered expression of genetic variants towards various complex diseases, transcriptome analysis is pivotal in present biological scenario. Availability of transcriptomic data of longan facilitates its further functional genomics analysis, differential gene expression analysis and progressive research on the plant varieties of similar family belonging to Indian subcontinent. In the present study, a total number of 90,762,826 mixed paired end sequence reads from 7 different tissues of longan transcriptome (ID: SRR2864836) and 64,876,528 reads for longan embryogenic callus (EC) transcriptome (ID: SRR412534) were downloaded from SRA database, NCBI using SRA Tool Kit. A total number of 9,304 and 10,679 contigs (including scaffolded regions) were assembled from the longan and longan-EC clean reads. Cloud blast search was performed against multiple protein and nucleotide databases at NCBI to explore the mechanistic insights, of the longan transcriptome. A total 9,304 contigs/ putative transcripts were classified into 10 major biological processes, 30 GO functional groups, 08 various cellular components and 139 KEGG pathways. In blast analysis against Nr database, database of Arabidopsis thaliana, Zea mays and Oryza sativa 33 contigs were reported for possessing disease resistant proteins. Additionally differential gene expression analysis between longan and longan-EC transcripts showed a total of 34 genes to be highly upregulated and 26 downregulated genes. Thus our study paves way for further research to improvise and utilize its economic and medicinal characteristics of longan as reference in context to Indian plants viz. Litchi chinensis, Arytera divericata, Schleichera oleosa (Lour.) etc.