Analysis of the CHS Gene Family Reveals Its Functional Responses to Hormones, Salinity, and Drought Stress in Moso Bamboo ().

Chalcone synthase (CHS), the first key structural enzyme in the flavonoid biosynthesis pathway, plays a crucial role in regulating plant responses to abiotic stresses and hormone signaling. However, its molecular functions remain largely unknown in , which is one of the most economically and ecologically important bamboo species and the most widely distributed one in China. This study identified 17 genes in and classified them into seven subgroups, showing a closer evolutionary relationship to genes from rice. Further analysis of genes across nine scaffolds revealed that most expansion occurred through tandem duplications. Collinearity analysis indicated strong evolutionary conservation among genes. Motif and gene structure analyses confirmed high structural similarity, suggesting shared functional characteristics. Additionally, -acting element analysis demonstrated that genes are involved in hormonal regulation and abiotic stress responses. RNA-Seq expression profiles in different bamboo shoot tissues and heights, under various hormone treatments (gibberellin (GA), naphthaleneacetic acid (NAA), abscisic acid (ABA), and salicylic acid (SA)), as well as salinity and drought stress, revealed diverse response patterns among genes, with significant differential expression, particularly under hormone treatments. Notably, consistently maintained high expression levels, suggesting its key role in stress response mechanisms. qRT-PCR analysis further validated the expression differences in five genes under GA and ABA treatments. Subcellular localization analysis demonstrated that PeCHS14 and PeCHS15 proteins are localized in the nucleus. This study provides a foundation for investigating the potential functions of genes and identifies candidate genes for future research on the responses of to abiotic stresses and hormone signaling.