Genome-Wide Identification and Functional Analysis of () in Three Species.

Intercellular communication mediated by CLAVATA3/EMBRYO SURROUNDING REGION-RELATED (CLE) peptides and their receptors is crucial for plant development and environmental adaptation. In this study, 45 and 89 were identified in and × , respectively, and, together with the 52 in , the chromosome localization, gene and protein characteristics, collinearity and gene duplication events, cis-acting regulatory elements in promoters and evolutionary relationships of in these three poplar species were analyzed. The of three poplar species were divided into four subfamilies. Among them, the in subfamilies I, II and IV were A-type , while those in subfamily III were B-type . During the evolutionary process of poplar, the selection pressure faced by whole-genome duplication or segmental duplication was purifying selection, and the duplication events led to the expansion of the family in poplar. The exogenous addition of a certain concentration of poplar CLE13 peptides inhibits the root growth of and poplar and simultaneously reduces the expression levels of and in the roots. In addition, drought stress induces the expression of . The overexpression of significantly enhances the osmotic and drought tolerance in . These results have provided valuable information for further research on the molecular mechanisms of CLE peptide signaling pathways in the woody model plant poplar regarding plant growth and stress resistance.