Plant genomics underpins a foundation for understanding evolution, gene regulation, and fundamental biological processes, subsequently supporting both the conservation and innovative utilization of plant germplasm resources. The Lythraceae family encompasses numerous species of economic and ecological significance, and are valued for their edible, medicinal, and ornamental properties. The family-wide distribution, spanning extreme intertidal zones, semi-deserts and tropical forests, positions Lythraceae as an exemplary model for investigating the genomic mechanisms underlying ecological adaptation. Recent advances in chromosome-level genomes, pan-genomics, genetic mapping, multi-omics integration, and large-scale phenotyping have greatly accelerated research in plant evolution and breeding. Nevertheless, despite the growing genomic and trait-focused studies in Lythraceae, a comprehensive conceptual synthesis linking evolutionary events, structural variation (SV), regulatory networks, and future research directions remain absent. In this review, we present an overview of genomic resources and introduce a unified framework linking whole-genome duplications, lineage-specific SVs, and their functional impacts on species diversification. We also synthesize recent advances in genome evolution, phylogenetic relationships, biotechnology, and molecular mechanisms controlling growth, development, and stress responses. In addition, we address challenges associated with genetic transformation of woody Lythraceae species and discuss strategies to enhance molecular breeding. This review provides a forward-looking perspective on Lythraceae genomics and identifies key scientific questions that will steer future research in evolutionary biology, functional genomics, and crop improvement.

Purple-leafed plants not only have a higher resistance to biotic and abiotic stresses, but also have higher ornamental value. Anthocyanins are vital for leaf color formation, growth and development of purple leaves. However, the molecular mechanism underlying purple leaf formation in Lagerstroemia indica remains unclear. Metabolomic and transcriptomic analysis of purple-leafed cultivar ‘Ebony Embers’ and green-leafed cultivar ‘Arapahoe’ showed that the high expression of anthocyanin structure genes induced hyperaccumulation of cyanidin and pelargonidin derivatives, making the leaves purple. LfiHY5, LfiMYB75 and LfibHLH1 were identified using correlation analysis and weighted gene co-expression network analysis. In ‘Arapahoe’ × ‘Ebony Embers’ population, LfiHY5 and LfiMYB75 showed significant positive correlation with leaf anthocyanin content. Transient expression of LfiMYB75 and LfiHY5 in tobacco and purple-leafed crape myrtle indicated that the two genes activated anthocyanin synthesis. Yeast two-hybrid analysis showed that LfiMYB75 and LfibHLH1 could form a complex that enhanced anthocyanin synthesis. Yeast monohybrid and dual-luciferase assays confirmed that LfiHY5 activated the expression of LfiMYB75, to activate the transcription of anthocyanin structural genes LfiCHS and LfiANS. Moreover, there were three alleles of LfiHY5 in crape myrtle, and the different sequences had different activation effects on LfiMYB75. In conclusion, the results showed that LfiHY5 led to upregulate the transcription of LfiMYB75, and LfiMYB75 formed a complex with LfibHLH1, which increased the transcription level of LfiCHS and LfiANS to affect anthocyanin synthesis in crape myrtle.

To understand the functional identification of large-scale genomic sequences in Forsythia, tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS), suitable for the plant, was explored in this study. The results showed that the TRV-mediated VIGS system could be successfully used in Forsythia for silencing the reporter gene FsPDS (Forsythia phytoene desaturase) using stem infiltration and leaf infiltration methods. All the treated plants were pruned below the injection site after 7–15 d infection; the FsPDS was silenced and typical photobleaching symptoms were observed in newly sprouted leaves at the whole-plant level. Meanwhile, this system has been successfully tested and verified through virus detection and qRT-PCR analysis. After the optimization, Forsythia magnesium chelatase subunit H (FsChlH) was silenced successfully in Forsythia using this system, resulting in yellow leaves with decreased chlorophyll content. The system was stable, highly efficient and had greater rapidity and convenience, which made it suitable to study the function of genes related to physiological pathways such as growth and development, and metabolic regulation in Forsythia.