Genome-Wide Identification of the Peanut ASR Gene Family and Its Expression Analysis under Abiotic Stress

Peanut (<i>Arachis hypogaea</i> L.) is one of the most important oil and food legume crops worldwide. <i>ASR</i> (abscisic acid, stress, ripening) plays extremely important roles in plant growth and development, fruit ripening, pollen development, and stress. Here, six <i>ASR</i> genes were identified in peanut. Structural and conserved motif analyses were performed to identify common ABA/WDS structural domains. The vast majority of <i>ASR</i> genes encoded acidic proteins, all of which are hydrophilic proteins and localized on mitochondria and nucleus, respectively. The cis-element analysis revealed that some cis-regulatory elements were related to peanut growth and development, hormone, and stress response. Under normal growth conditions, <i>AhASR4</i> and <i>AhASR5</i> were expressed in all tissues of peanut plants. Quantitative real-time PCR (qRT-PCR) results indicated that peanut <i>ASR</i> genes exhibited complex expression patterns in response to abiotic stress. Notably, under drought and cadmium (Cd) stress, the expression levels of <i>AhASR4</i> and <i>AhASR5</i> were significantly upregulated, suggesting that these genes may play a crucial role in the peanut plant's resistance to such stressors. These results provide a theoretical basis for studying the evolution, expression, and function of the peanut <i>ASR</i> gene family and will provide valuable information in the identification and screening of genes for peanut stress tolerance breeding.