Transcriptomic analysis revealed adverse effect of melatonin on root growth

Purpose: We aimed to compare transcriptomic changes after high concentration melatonin treatment in Arabidopsis Methods: A total amount of 3 μg RNA was used for generation of sequencing libraries using NEBNext® Ultra™ RNA Library Prep Kit for Illumina® (NEB, USA) following manufacturer’s recommendations and index codes were added to attribute sequences to each sample. After cluster generation, the library preparations were sequenced on an Illumina Hiseq platform and 125 bp/150 bp paired-end reads were generated. Clean reads were obtained by removing low quality reads, reads containing adapter and ploy-N from raw data. At the same time, Q20, Q30 and GC content the clean data were calculated. Index of the Arabidopsis genome was built using Bowtie v2.2.3 and paired-end clean reads were aligned to the reference genome using TopHat v2.0.12. HTSeq v0.6.1 was used to count the reads numbers mapped to each gene. And then FPKM (Fragments Per Kilobase of transcript sequence per Millions base pairs sequenced) of each gene was calculated based on the length of the gene and reads count mapped to this gene. Differential expression analysis of drought stress versus control condition was performed using the DESeq R package (1.18.0). Results:In total, eight samples with two biological replicates per genotype/treatment combination were used for RNA sequencing analysis. At least 2 G clean bases were generated for each sample. Comparative analysis revealed different networks which were modulated by melatonin and IAA in Arabidopsis seedlings In this study, wild type Arabidopsis plants were grown in MS plate for 7 days.Plants were then treated with 0,100 and 1000μM melatonin for 12h. The rosette leaves were then collected for RNA isolation and deep sequencing.