Genome-wide identification and comparative analysis of strigolactone biosynthetic genes in major solanaceous crops

Strigolactones (SLs) are a class of important plant hormones that not only regulate plant growth and development but also mediate responses to biotic and abiotic stresses. Functioning as signaling molecules derived from the rhizosphere, SLs play a pivotal role in inducing the germination and facilitating the parasitism of root holoparasites such as Orobanche spp. Notably, the parasitism success of Orobanche exhibits marked variation within Solanaceous crops, demonstrating dual dependence on SL exudation dynamics and edaphic phosphate bioavailability. We performed a genome-wide characterization of SL biosynthetic orthologs across nine Solanaceous species through integrated phylogenomic pipelines alongside qRT-PCR expression profiling. In this study, we identified 113 putative SL biosynthetic orthologs across wolfberry, nightshade, tomato, eggplant, petunia, tobacco, pepper, groundcherry and potato, revealing both deep evolutionary conservation and lineage-specific diversification patterns. Phosphate deprivation significantly induced the upregulation of SL biosynthetic genes in tomato and pepper via qRT-PCR analysis, confirming that phosphorus deficiency acts as a key stimulator of SL biosynthesis. In general, this study delineates the repertoire of potential SL biosynthesis-related genes across major Solanaceous species, revealing phylogenetic conservation and clade-specific diversification.