Comparative transcriptome analysis of Chrysanthemum nankingense in response to nitrogen deficiency

- The transcriptome of chrysanthemum under nitrogen limitation was sequenced.
- 1510 and 686 different expressed genes were identified in the root and leaf.
- Molecular basis of response to nitrogen stress in chrysanthemum was characterized.
- Our results will help to enhance tolerance of chrysanthemum in nitrogen deficiency.

The diploid Chrysanthemum L. species Chrysanthemum nankingense is a native plant in China, which is related to the commercially important polyploidy ornamental species Chrysanthemum morifolium (the garden chrysanthemum). As nitrogen is a limited element for plant growth, finding out genes responding to low nitrogen stress is important for improving the nitrogen-use efficiency. The transcriptome of C. nankingense was sequenced using roots and leaves of plants grown in the presence of either 4 mM or 0.04 mM nitrate. About 7,000,000 clean reads were generated from each of the four libraries. A total of 1510 and 686 differentially transcribed genes were identified in the roots and leaves, respectively. Many of the differentially transcribed genes were involved in photosynthesis and nitrogen metabolism, along with a number of transcription factors and genes encoding protein kinases. qPCR results of 15 randomly selected genes validated the RNA-Seq output. The molecular basis of the response to nitrogen stress in C. nankingense was comprehensively characterized. Overall, our results may be useful for breeding new chrysanthemum varieties with enhanced tolerance to nitrogen deficiency.