*Article* **Whole-Transcriptome Sequence Analysis of** *Verbena bonariensis* **in Response to Drought Stress**

**Bei Wang <sup>1</sup> , Xue-Qi Lv <sup>1</sup> , Ling He <sup>1</sup> , Qian Zhao <sup>1</sup> , Mao-Sheng Xu <sup>1</sup> , Lei Zhang <sup>1</sup> , Yin Jia <sup>1</sup> , Fan Zhang <sup>1</sup> , Feng-Luan Liu 2,\* and Qing-Lin Liu 1,\***


Received: 20 April 2018; Accepted: 8 June 2018; Published: 13 June 2018

**Abstract:** Drought is an important abiotic factor that threatens the growth and development of plants. *Verbena bonariensis* is a widely used landscape plant with a very high ornamental value. We found that Verbena has drought tolerance in production practice, so in order to delve into its mechanism of drought resistance and screen out its drought-resistance genes, we used the RNA-Seq platform to perform a de novo transcriptome assembly to analyze Verbena transcription response to drought stress. By high-throughput sequencing with Illumina Hiseq Xten, a total of 44.59 Gb clean data was obtained from T01 (control group) and T02 (drought experiment group). After assembly, 111,313 unigenes were obtained, and 53,757 of them were annotated by compared databases. In this study, 4829 differentially expressed genes were obtained, of which 4165 were annotated. We performed GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analyses, and explored a lot of differently expressed genes related to plant energy production, hormone synthesis, cell signal transduction, and metabolism to understand the stress response of Verbena in drought stress. In addition, we also found that a series of TFs related to drought-resistance of Verbena and provide excellent genetic resources for improving the drought tolerance of crops.

**Keywords:** *Verbena bonariensis*; drought stress; transcriptome sequencing; differentially expressed genes
