Abstract
As an important economic crop, the growth and development of kiwifruit are sensitive to environmental stresses, which can lead to reduced yield and quality. Leucine-rich repeat receptor-like kinases (LRR-RLKs) constitute one of the largest groups of receptor-like kinases and play crucial roles in regulating plant growth and development, as well as responses to biotic and abiotic stresses. In this study, 307 LRR-RLK genes were identified in the kiwifruit genome and grouped into 13 subclades. A comprehensive analysis was conducted, encompassing physiochemical properties, evolutionary relationships, gene structure, conserved motifs, gene family expansion, functional annotation, tissue-specific expression, and responses to stresses. Members within each subclade displayed analogous conserved motifs, gene structures, and protein structures. During gene family expansion, 47.9% AcLRR-RLK genes originated from tandem or segmental duplication events and evolved under strong purifying selection. Most AcLRR-RLK genes were differentially expressed in kiwifruit tissues, with some members exhibited continuously increased expression during the fruit ripening process. Furthermore, a series of differentially expressed AcLRR-RLK genes were detected under biotic and abiotic stresses. This study establishes a foundational framework for understanding LRR-RLK members and provides valuable insights into the potential applications of molecular breeding in kiwifruit cultivation.