Genome-Wide Identification and Expression Analysis of 1-Aminocyclopropane-1-Carboxylate Synthase ( ACS ) Gene Family in Chenopodium quinoa

Ethylene plays an important role in plant development and stress resistance. The rate-limiting enzyme in ethylene biosynthesis is 1-aminocyclopropane-1-carboxylic acid synthase (ACS). ( ) is an important food crop known for its strong tolerance to abiotic stresses. However, knowledge regarding the gene family in remains restricted. In this study, we successfully identified 12 genes ( ) from the genome. Through thorough analysis of their sequences and phylogenetic relationships, it was verified that 8 out of these 12 CqACS isozymes exhibited substantial resemblance to ACS isozymes possessing ACS activity. Furthermore, these eight isozymes could be categorized into three distinct groups. The four remaining genes grouped under category IV displayed notable similarities with and , known as amido transferases lacking ACS activity. The CqACS proteins bore resemblance to the AtACS proteins and had the characteristic structural features typically observed in plant ACS enzymes. Twelve genes were distributed across 8 out of the 18 chromosomes of . The genes were expanded from segment duplication. Many cis-regulatory elements related with various abiotic stresses, phytohormones, and light were found. The expression patterns of genes varied across different tissues of . Furthermore, the analysis of gene expression patterns under abiotic stress showed that genes can be responsive to various stresses, implying their potential functions in adapting to various abiotic stresses. The findings from this research serve as a foundation for delving deeper into the functional roles of genes.