Double flowers are one of the important objectives of ornamental plant breeding. Sagittaria sagittifolia is an aquatic herb in the Alismataceae family that is widely used as an ornamental plant in gardens. However, the reference genome has not been published, and the molecular regulatory mechanism of flower formation remains unclear. In this study, single molecule real-time (SMRT) sequencing technology combined with Illumina RNA-Seq was used to perform a more comprehensive analysis of S. sagittifolia for the first time. We obtained high-quality full-length transcripts, including 53,422 complete open reading frames, and identified 5980 transcription factors that belonged to 67 families, with many MADS-box genes involved in flower formation being obtained. The transcription factors regulated by plant hormone signals played an important role in the development of double flowers. We also identified an AP2 orthologous gene, SsAP2, with a deletion of the binding site for miR172, that overexpressed SsAP2 in S. sagittifolia and exhibited a delayed flowering time and an increased number of petals. This study is the first report of a full-length transcriptome of S. sagittifolia. These reference transcripts will be valuable resources for the analysis of gene structures and sequences, which provide a theoretical basis for the molecular regulatory mechanism governing the formation of double flowers.

To investigate the relationship between the rhizosphere microbial community structure and lotus root texture, the biological properties, and the rhizosphere microbial composition of mealy (ML) and crunchy lotus (CL) varieties were all analyzed using traditional and high-throughput sequencing technologies. The results showed that the ML varieties exhibited significantly lower moisture but higher starch contents than those of CL. Meanwhile, the rhizosphere fungal richness of ML was also significantly higher than that of CL. Moreover, the relative abundances of bacterial phyla and genera, such as Nitrospirota, Bacteroidota, Proteobacteria, and Bacillus, alongside fungal phyla and genera, i.e., Ascomycota and Emericellopsis, were enriched in rhizosphere of ML compared to CL. Functional prediction also revealed that elevated nitrogen cycling, polysaccharide degradation and cellulose breakdown functions could be detected in ML, potentially driving starch accumulation and cell wall modification. These results suggest that rhizosphere microbial composition, particularly nitrogen-cycling bacteria and lignocellulose-degrading fungi, may contribute to texture formation between texture-differentiated lotus root varieties.

Lotus root texture significantly influences consumer preferences and market value, yet the role of endophytes in determining the distinct mealy (ML) and crunchy (CL) textural properties remains unclear. This study aimed to clarify the relationship between endophyte composition and metabolic characteristics underlying the texture differences between ML and CL lotus root varieties. Two lotus root varieties (ML and CL) were analyzed for endophytic microbial communities using high-throughput sequencing methods. Metabolite profiling of cellulose, starch, pectin, soluble sugars, and proteins was conducted using standard biochemical assays. The findings revealed higher cellulose, starch, and pectin content in mealy lotus root (ML) varieties than those in crunchy lotus root (CL) varieties. Additionally, the functions of cellulose-degrading and protein-producing microorganisms, such as Firmicutes, Bacteroides, Exiguobacterium, Bradyrhizobium, and Basidiomycota, were primarily enriched in the ML varieties. In contrast, the CL varieties had specific dominant endophytic bacterial genera, such as Myxococcota, Geobacter, Paludibacteraceae, Rhodocyclaceae, Comamonadaceae, Micromonosporaceae, Sideroxydans, Bacillus, Lactococcus, Oxalobacteraceae, and Treponema. These results indicate that different endophytes are associated with the development of mealy and crunchy properties. Understanding these microbial–metabolic relationships offers practical implications for selective breeding and agricultural management aimed at texture improvement. Future research should elucidate the specific metabolic pathways regulated by these endophytes to facilitate targeted agricultural interventions.