Genome-Wide Identification of Rubber Tree SCAMP Genes and Functional Characterization of HbSCAMP3

Natural rubber produced by the rubber tree is a vital industrial raw material globally. Seven SCAMP gene family members were identified in the rubber tree, and the phylogenetic tree classified HbSCAMPs into three subfamilies. Significant differences were observed among HbSCAMPs in terms of gene length, number of exons, and composition of conserved motifs. The expansion of HbSCAMPs in the rubber tree genome is associated with segmental duplications. The high expression of HbSCAMP1-6 in petioles and HbSCAMP7 in stem tips, along with their distinct responses to drought, salt, and wound stresses, indicates their crucial roles in substance transport and stress adaptation. Transgenic poplar experiments demonstrated that overexpression of HbSCAMP3 significantly promotes plant height growth, with localization in the tobacco plasma membrane, suggesting its involvement in regulating plant growth through membrane transport processes. These findings enhance the understanding of HbSCAMPs in rubber trees and provide new insights into how plants finely tune gene family members to adapt to environmental changes.