Expression data of four wheat genotypes viz. HD2967, K307, K9107 and Chotilarma (CL) in response to nitrogen chronic limitation

The transcriptome profile was examined in four wheat genotypes in roots and shoots under nitrogen stressed condition which indicates genotype specific transcript data-set apart from the common transcripts. Unique genes was identified for nitrogen uptake and utilization process. We used microarrays to detail the gene expression and identify the candidate genes related to uptake and utilization of nitrogen in root and shoot tissues of wheat genotypes. We collected seedlings from four wheat genotypes viz., HD2967, K9107, K307 and Chotilarma (CL) grown for 15 days in pots containing mixture of vermiculite and perlite in a ratio 2:1. Three sets of pots for each genotype were grown in two different conditions : control including 8mM Ca(NO3)2 and nitrogen starved condition 0.08mM Ca(NO3)2 as source. Total RNA isolated from these tissue samples and amplified RNA were purified and labeled by biotin with GeneChip® IVT labeling kit. The biotinylated cDNAs were fragmented and hybridized to the Affymetrix GeneChip® Wheat Genome Array (Affymetrix, Inc., Carlsbad, CA) for 16 hours. Normalization of the microarray data was conducted using Robust Multichip Average (RMA) algorithm with Affymetrix® GeneChip® Command Console® Software (AGCC) used to analyze the data. Transcriptome profiling was detected in all four different wheat genotypes for N+ and N- plants. Each array dataset was then imported into Agilent GeneSpring software 14.5 for analysis. The signal intensities of the samples were transformed into log2-ratio data. Normalized data with a p-value of ≤ 0.1 that passed a Student’s t- test was used to identify differentially expressed genes.