Transcriptional Regulations on the Low-Temperature-Induced Floral Transition in an Orchidaceae Species, Dendrobium nobile: An Expressed Sequence Tags Analysis

Figure 6

Predicted vernalization regulation networks in D. nobile. By comparative analysis with Arabidopsis and temperate cereal, we found many D. nobile unigenes induced by vernalization are homologs or functional equivalents of the flowering regulators. These homologs (highlighted in red) involve two vernalization pathways, one is the Arabidopsis AGL19 pathway and the other is the cereal VRN1 pathway. FLC homolog cannot be identified from D. nobile and this indicates that FLC mediated regulation might be absent or be repressed during vernalization process. Networks to regulate flowering by the vernalization, similar to those in Arabidopsis and temperate cereal, are proposed in D. nobile. It should be noted that this network must be confirmed by more extensive studies basing on more solid evidences. The network chats of Arabidopsis and temperate cereal are adopted from the article by Alexandre and Hennig [1], or are summarized according to the descriptions in articles by Higgins et al. [8], Kim et al. [2], and Trevaskis et al. [9, 10].