Genome-wide Identification and Analysis of RAV Gene Family in Phoebe bournei, an Endangered Plant

Phoebe bournei, a rare and endangered endemic tree species in China, holds significant importance for ecological protection and economic utilization through genetic improvement and stress resistance mechanism research. Based on the whole-genome data of P. bournei, this study systematically identified and analyzed the physicochemical properties, structural characteristics, and expression profiles of the RAV gene family using bioinformatics approaches. The results showed that five RAV gene family members (PbRAV01–PbRAV05) were identified in P. bournei, all localized in the nucleus, hydrophilic, and dispersedly distributed on five chromosomes, exhibiting structural diversity and tissue expression specificity. These genes are enriched in light-responsive, drought-responsive, and hormone-responsive elements, suggesting their involvement in stress regulation and hormone signal transduction. Intraspecific collinearity analysis revealed a segmental duplication event between PbRAV02 and PbRAV05, while interspecific collinearity indicated a closer genetic relationship between P. bournei and rice RAV genes. Phylogenetic tree analysis classified the genes into three subfamilies, among which PbRAV03 and PbRAV04 in Subfamily A were closely evolutionarily related to Arabidopsis AtRAV03. Tissue expression analysis showed that PbRAV05 was highly expressed in roots, stems, and leaves, while PbRAV02 was preferentially expressed in roots. This study provides a theoretical basis for molecular breeding and stress resistance mechanism analysis of P. bournei, and offers new insights into the phylogenetic research of Magnoliids.