Genomic and Functional Analysis of the Abscisic Acid Receptor PYL Gene Family in Sugarcane and the Positive Roles of ScPYL8 Under Pathogen Stress

PYL proteins are core components of the abscisic acid (ABA) signaling pathway and are involved in plant responses to biotic and abiotic stresses. In this study, a total of 19, four, and eight PYL genes were identified in Saccharum spontaneum, the Saccharum spp. hybrid R570, and Sorghum bicolor, respectively. Phylogenetic analysis classified these PYL genes into three distinct groups. Cis-acting element analysis, Gene Ontology annotation, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment and gene expression profile indicated that members of the PYL gene family are mainly associated with hormone signaling and stress-related biological processes. The ScPYL8 gene (GenBank accession number: OR838856) was isolated from sugarcane cultivar QT3. Expression of the ScPYL8 gene was induced under stresses of cold, PEG, SA, MeJA, ABA, and brown stripe disease (Bipolaris setariae). The gene was expressed in roots, stems and leaves, with the highest expression level in leaves. Subcellular localization analysis showed that the ScPYL8 protein localized to the cytoplasm and nucleus. ScPYL8 overexpression in tobacco activated the reactive oxygen species defense system and regulated the ABA and jasmonic acid signaling pathways, enhancing its resistance against Fusarium solani var. coeruleum. These findings provide insights into the expression, function, and evolutionary characteristics of the PYL gene family in sugarcane, offering valuable genetic resources for future molecular breeding.