Haplotype‐resolved genome assembly provides insights into the evolution of S‐locus supergene in distylous Nymphoides indica

• DOI: 10.1111/nph.19264
• Publication Date: 2023-09-17T13:59:20Z
• Authors: Jingshan Yang; Haoran Xue; Zhizhong Li; Yue Zhang; Tao Shi; Xiangyan He; Spencer C. H. Bar...; Qingfeng Wang; Jinming Chen
• Keywords: Supergene (geology); Heterostyly; Comparative Genomics

Distyly has evolved independently in numerous animal-pollinated angiosperm lineages. Understanding of its molecular basis been restricted to a few species, primarily Primula. Here, we investigate the genetic architecture single diallelic locus (S-locus) supergene, linkage group functionally associated genes, and explore how it may have distylous Nymphoides indica, lineage flowering plants not previously investigated. We assembled haplotype-resolved genomes, used read-coverage-based genome-wide association study (rb-GWAS) locate S-locus co-expression network analysis gene networks underpinning development distyly, comparative genomic analyses origins supergene. identified three linked candidate genes - NinBAS1, NinKHZ2, NinS1 that were only evident short-styled morph hemizygous. Co-expression suggested brassinosteroids contribute dimorphic sex organs morph. Comparative indicated supergene likely via stepwise duplications affected by transposable element activities. Our provides novel insight into structure, regulation, evolution governing distyly N. indica. It also high-quality resources for future research on mechanisms underlying striking evolutionary convergence form function across heterostylous taxa.