Identification of differentially expressed genes in Chrysanthemum nankingense (Asteraceae) under heat stress by RNA Seq

The RNA-Seq platform was used to characterize the high-temperature stress response of Chrysanthemum nankingense. A set of 54,668 differentially expressed unigenes was identified. After a threshold of ratio change >= 2 and a q-value of <0.05 were applied, the number of differentially transcribed genes was reduced to 3955, of which 765 were up-regulated and 3190 were down-regulated in response to heat stress. The differentially transcribed genes were predicted to participate in 26 biological processes, 4 cellular components, and 13 molecular functions. Among the most differentially expressed genes between the two libraries were well-recognized high-temperature responsive protein families, such as heat shock factors and heat shock proteins, various transcription factor families, and a number of RNA metabolism-related genes. Overall, the RNA-Seq analyses revealed a high degree of transcriptional complexity in early heat stress response. Some of these high-temperature responsive C. nankingense genes may prove useful in efforts to improve thermotolerance of commercial chrysanthemum. (C) 2014 Elsevier B.V. All rights reserved.