**5. Conclusions**

This study compared the NLR gene profiles in five Arecaceae species and revealed a high NLR content and structure variation, which serve as a resource for the evolution of functional NLR genes. Phylogenetic analysis revealed that NLR genes from the five genomes were derived from 101 ancestral genes, and distinct "consistent expansion" and "first expansion and then contraction" patterns were observed for NLR genes from the five species. The results show that dynamic gene content and structure variation have shaped the NLR profiles of different Arecaceae species. The obtained NLR profiles serve as a valuable resource for molecular breeding of these species and for further exploration of the NLR evolutionary pattern.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/horticulturae7120539/s1, Figure S1. 101 NLR gene families divided based on NLR phylogeny from *C. simplicifolius, D. jenkinsiana, P. dactylifera, E. guineensis* and *C. nucifera*. Figure S2. Phylogenetic distribution of NLRgenes with different domain compositions in five Arecaceae species. Table S1. The gene list and classification of NLR genes identified from *C. simplicifolius, D. jenkinsiana, P. dactylifera, E. guineensis* and *C. nucifera*. Table S2. Exogenous fusion domains of NLR identified from five Arecaceae species. Data S1. An NEXUS format phylogenetic tree of NLRs in five Arecaceae species with branch support values.

**Author Contributions:** Z.-Q.S. and Y.L. conceived and designed the study. X.-T.L., G.-C.Z., X.-Y.F., Z.Z. and Y.L. obtained and analyzed the data. X.-T.L. and G.-C.Z. wrote the manuscript. Z.-Q.S. and Y.L. revised the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** The authors have no conflict of interest to declare.
