Fig. 2: Adaptive evolution analysis of the LAC family in P. euphratica, expression pattern and subcellular localization of PeuLAC2.

a A maximum likelihood (ML) phylogenetic tree of all 40 PeuLACs. All PeuLAC genes clustered into six clades (I–VI). Red letters and red stars represent the signals of positive selection detected in ancestral branches (branches D and F and subbranches a, b, d, e, and g). In branches A, B, C, and E and subbranches c, f, and h, no signals of positive selection were detected. The red circle represents the signal of positive selection detected in terminal branch PeuLAC2. b Sequence alignments and six positive selection sites. Alignments of PeuLACs in clade VI terminal branches (PeuLAC1, PeuLAC2, PeuLAC3) and ancestral branches (branch F and branch h) were generated by DNAMAN software. Positive selection sites are indicated with asterisks. c Expression of PeuLAC2 examined by qRT-PCR in the leaves, roots, xylem and phloem of P. euphratica. d Subcellular localization of the PeuLAC2 protein; 48 h after transient expression in Nicotiana benthamiana, confocal images of PeuLAC2 fused to an N-terminal YFP and of the control 35S::YFP were obtained. YFP-only images, brightfield images, and merged images are shown