Abstract:

Pugionium dolabratum is a xerophytic plant species mainly distributed in fixed or semi-fixed desert in northwest China， which possess strong adaptability to arid environment. However， the molecular mechanism of drought stress tolerance in P. dolabratum was known much less. In this study， we used Illumina sequencing to screen drought responsive genes in P. dolabratum， 154 875 unigenes with an average length of 1 437 nt were obtained by De novo transcriptome assembly. After drought stress， a total of 13 855 unigenes was significantly and differentially expressed， of which 7 182 genes were up-regulated and 6 673 genes were down regulated. GO enrichment analysis showed that the differentially expressed genes were significantly enriched in material metabolism， oxidoreductase and catalytic activity. KEGG enrichment analysis showed that the differentially expressed genes were significantly enriched in amino acid metabolism， starch and sucrose metabolism and plant hormone signal transduction. In addition， we identified 47 drought induced transcription factor families， mainly including HSF， ERF， WRKY， MYB， and bHLH. Compared with P. cornutum， the starch and sucrose metabolism and the up-regulated expression of heat stress transcription factors may be an alternative pathway to enhance tolerance capacity in P. dolabratum in response to drought stress. The results preliminarily revealed the regulatory characteristics of P. dolabratum in response to drought stress， and provided important clues for further insight into the molecular mechanism of drought environment adaptation in P. dolabratum.

Key words: Pugionium dolabratum, drought stress, transcriptome, transcription factor