Genome-Wide Identification and Expression Analysis of the Casparian Strip Membrane Domain Protein-like Gene Family in Peanut ( Arachis hypogea L.) Revealed Its Crucial Role in Growth and Multiple Stress Tolerance

Casparian strip membrane domain proteins (CASPs), regulating the formation of Casparian strips in plants, serve crucial functions in facilitating plant growth, development, and resilience to abiotic stress. However, little research has focused on the characteristics and functions of in cultivated peanuts. In this study, the genome-wide identification and expression analysis of the gene family was performed using bioinformatics and transcriptome data. Results showed that a total of 80 members on 20 chromosomes were identified and divided into three subclusters, which mainly localized to the cell membrane. Ka/Ks analysis revealed that most of the genes underwent purifying selection. Analysis of elements suggested the possible involvement of in hormonal and stress responses, including GA, MeJA, IAA, ABA, drought, and low temperature. Moreover, 20 different miRNAs for 37 different genes were identified by the psRNATarget service. Likewise, transcriptional analysis revealed key responding to various stresses, hormonal processing, and tissue types, including 33 genes in low temperature and drought stress and 41 genes in tissue-specific expression. These results provide an important theoretical basis for the functions of in growth, development, and multiple stress resistance in cultivated peanuts.