A single nucleotide polymorphism in EXECUTER 1 is a strong candidate locus for the leaf color variation in sponge gourd

As a key agronomic trait, leaf color is closely linked to plant photosynthetic efficiency. In this study, we investigated the genetic mechanisms of leaf color variation in sponge gourd using an F 2 population generated from two phenotypically distinct parents. Through bulked segregant analysis (BSA), a 4.89 Mb candidate region related to leaf color was mapped on chromosome 8. Further combination of resequencing and fine mapping analysis identified a non-synonymous SNP variation in the exon of the EXECUTER 1 ( EX1 ). We verified its function through homologous gene mutation in Arabidopsis thaliana , revealing its role in leaf color variation and its significant impact on photosynthetic performance. Furthermore, a functional molecular marker developed based on this SNP showed strict co-segregation with the leaf color phenotypes in the F 2 population. This study provides vital insights into the molecular basis of leaf color trait in sponge gourd and establishes a solid foundation for marker-assisted breeding targeting enhanced photosynthetic traits.