Transcriptome analysis of cucumber response to nitrogen deficiency

Nitrogen is the most important mineral nutrient of plant. As a worldwide and economically important vegetable, cucumber (Cucumis sativus L.) has a strong nitrogen-dependence. We took whole transcriptome sequencing approach to compare the gene expression profiles of cucumber leaves and roots grown under sufficient or insufficient nitrate supply. Analysis of the transcriptome data revealed that the root and leaf adapt different response mechanisms to long-term nitrogen deficiency. Photosynthesis and carbohydrate biosynthetic process were pronouncedly and specifically reduced in leaf, while the ion transport function, cell wall and phosphorus-deficiency response function seem systematically down-regulated in root. Genes in nitrogen uptake and assimilation are decreased in root, but some are increased in leaf under nitrogen deficiency. Several lines of evidence suggest that the altered gene expression networks support the basic cucumber growth and development likely through successful nitrogen remobilization involving in the induced expression of genes in ABA and ethylene pathways. Overall design: cucumber leaf and root mRNA of 28-day after sowing nitrogen deficiency and sufficiency deep sequencing, using Illumina HiSeq 2000