Abstract
INTRODUCTION: Wall-associated receptor kinases (WAKs) are a family of receptor-like kinases (RLKs) that play important roles in the communication between the plant cell wall and the cytoplasm. WAKs have been identified in several plants. However, a comprehensive investigation of maize WAKs has not been performed yet. METHODS: In this study, the maize WAK gene family was identified through whole-genome scanning. y -30The physicochemical characteristics, chromosomal locations, phylogenetic tree, gene structures, conserved motifs, gene duplication, collinearity, and cis-acting elements of maize WAKs were analyzed. RESULTS: A total of 56 ZmWAKs were identified in the maize genome and divided into seven subgroups. Among these, 54 genes were successfully mapped to maize chromosomes. Gene duplication events were detected in 13 ZmWAKs, with nine segmental (SD) and two tandem duplication (TD) events. Maize WAKs exhibited zero, eight, 27, and 41 collinear links with the WAKs from Arabidopsis, soybean, rice, and sorghum, respectively. In the promoter regions of ZmWAKs, a total of 107 types of cis-acting elements were predicted. Among them, the functions of 82 elements are known. These elements are associated with plant growth and development and light, hormones, stress, and defense responses. The transcriptome data analysis showed that ZmWAKs displayed tissue-specific expression and are involved in the responses to various abiotic and biotic stresses, including cold, salt, drought, waterlogging, pathogens, and pests. ZmWAK9, ZmWAK15, ZmWAK27, ZmWAK41, and ZmWAK49 are significantly induced by multiple stress conditions, indicating their crucial roles in stress responses and potential value for further research. DISCUSSION: Our results provide insights into the function of maize WAKs in response to abiotic and biotic stresses and offer a theoretical foundation for understanding their mechanisms of action.