RNA-seq of Ranunculus sceleratus and Identification of Orthologous Genes among Four Ranunculus Species

Ranunculus L. is an early diverging clade in the Angiosperm phylogeny. The split between terrestrial and aquatic/semi-aquatic lineages within the genus occurred within 20 Ma (Emadzade and Horandl, 2011), which is much younger than for some well-known aquatic lineages such as Ceratophyllum and Potamogeton. Ranunculus sceleratus Linn. is a semi-aquatic plant commonly found in paddy fields, streams and lakes in Asia, Europe and North America (eFlora of China, http://www.efloras.org/). The plant has also been studied for its unique toxicological and pharmacological properties (Prieto et al., 2003). Its karyotype is 2n = 32, x = 8 in mainland China (Yang, 2000). It usually roots in inundated soils, with stems and leaves emergent. The semi-aquatic R. sceleratus has been hypothesized to be an inter-mediate type in the transition from a terrestrial to aquatic habitat within the genus (Barrett et al., 1993; Prieto et al., 2003). In this study, we generated RNA-seq data of R. sceleratus and analyzed this in relation to the RNA-seq data of Ranunculus bungei Steud., Ranunculus cantoniensis DC., and Ranunculus brotherusii Freyn (Chen et al., 2015). Our aim was to generate RNA-seq data of R. sceleratus and identify the orthologous genes among the four species.