Figure 8: Comparison of representative C-repeat binding factor (CBF) protein family members in sandalwood, Arabidopsis (Arabidopsis thaliana (L.) Heynh.), poplar (Populus trichocarpa Torr. & A. Gray), and grape (Vitis vinifera L.).

(a) Alignment of AP2 and flanking region of CBF factors. The AP2/ERF domain, putative nuclear localization signal (NLS), and DSAWR motif are marked with a solid line and a dotted line, respectively. (b) A phylogenetic analysis of sandalwood, Arabidopsis, poplar, and grape proteins, based on minimum evolution, was performed with the full-length protein sequences using OsCBF1 as an out-group. Sequences were aligned using four sandalwood CBF proteins: SaCBF1 (KX009414), SaCBF2 (KX009415), SaCBF3 (KX009416), and SaCBF4 (KX009417), four poplar CBF proteins, PtCBF1 (JGI666968), PtCBF2 (JGI346104), PtCBF3 (JGI548519), and PtCBF4 (JGI63608), four Arabidopsis CBF proteins, AtCBF1 (ABV27072.1), AtCBF2 (ABV27106.1), AtCBF3 (ABV27138.1), and AtCBF4 (ABV27155.1), and four grape CBF proteins, VvCBF1 (AIL00526.1), VvCBF2 (AIL00632.1), VvCBF3 (AIL00730.1), and VvCBF4 (AIL00786.1). CBF proteins were initially aligned using CLUSTALX (v1.83) and used to conduct phylogenetic analyses using MEGA version 4. A phylogenetic tree was constructed using the neighbor-joining method on 1,000 bootstrap replications. Bootstrap percentages are shown on the dendrogram branch points.