Comparison of Whole Plastome Sequences between Thermogenic Skunk Cabbage <i>Symplocarpus renifolius</i> and Nonthermogenic <i>S. nipponicus</i> (Orontioideae; Araceae) in East Asia

• Main Authors: Seon-Hee Kim, JiYoung Yang, Jongsun Park, Takayuki Yamada, Masayuki Maki, Seung-Chul Kim
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: International Journal of Molecular Sciences
• Subjects: <i>Symplocarpus renifolius</i>; <i>Symplocarpus nipponicus</i>; proto-Araceae; plastome; thermogenesis; SSRs; phylogenetic analysis
• Online Access: https://www.mdpi.com/1422-0067/20/19/4678

<i>Symplocarpus</i>, a skunk cabbage genus, includes two sister groups, which are drastically different in life history traits and thermogenesis, as follows: The nonthermogenic summer flowering <i>S. nipponicus</i> and thermogenic early spring flowering <i>S. renifolius</i>. Although the molecular basis of thermogenesis and complete chloroplast genome (plastome) of thermogenic <i>S. renifolius</i> have been well characterized, very little is known for that of <i>S. nipponicus</i>. We sequenced the complete plastomes of <i>S. nipponicus</i> sampled from Japan and Korea and compared them with that of <i>S. renifolius</i> sampled from Korea. The nonthermogenic <i>S. nipponicus</i> plastomes from Japan and Korea had 158,322 and 158,508 base pairs, respectively, which were slightly shorter than the thermogenic plastome of <i>S. renifolius</i>. No structural or content rearrangements between the species pairs were found. Six highly variable noncoding regions (<i>psbC/trnS</i>, <i>petA/psbJ</i>, <i>trnS/trnG</i>, <i>trnC/petN</i>, <i>ycf4/cemA</i>, and <i>rpl3/rpl22</i>) were identified between <i>S. nipponicus</i> and <i>S. renifolius</i> and 14 hot-spot regions were also identified at the subfamily level. We found a similar total number of SSR (simple sequence repeat) motifs in two accessions of <i>S. nipponicus</i> sampled from Japan and Korea. Phylogenetic analysis supported the basal position of subfamily Orontioideae and the monophyly of genus <i>Symplocarpus</i>, and also revealed an unexpected evolutionary relationship between <i>S. nipponicus</i> and <i>S. renifolius</i>.