IiAGL6 participates in the regulation of stamen development and pollen formation in Isatis indigotica.

The AGL6 (AGMOUSE LIKE 6) gene is a member of the SEP subfamily and functions as an E-class floral homeotic gene in the development of floral organs. In this study, we cloned IiAGL6, the orthologous gene of AGL6 in Isatis indigotica. The constitutive expression of IiAGL6 in Arabidopsis thaliana resulted in a late-flowering phenotype and the development of curly leaves during the vegetative growth period. Abnormal changes in floral organ development were observed during the reproductive stage. In woad plants, suppression of IiAGL6 using TRV-VIGS (tobacco rattle virus-mediated virus-induced gene silencing) decreased the number of stamens and led to the formation of aberrant anthers. Similar changes in stamen development were also observed in miRNA-AGL6 transgenic Arabidopsis plants. Yeast two-hybrid and BiFC tests showed that IiAGL6 can interact with other MADS-box proteins in woad; thus, playing a key role in defining the identities of floral organs, particularly during stamen formation. These findings might provide novel insights and help investigate the biological roles of MADS transcription factors in I. indigotica.

[New steroidal saponins from aerial parts of Paris polyphylla var. chinensis].

The shortage of Paridis Rhizoma promotes comprehensive utilization and development research of waste aerial parts of the original plant. The chemical compositions of the aerial parts of Paris polyphylla var. chinensis were clarified based on the ultrahigh performance liquid chromatography tandem quadrupoles time of flight mass spectrometry(UPLC-QTOF-MS/MS) in the previous investigation, and a series of flavonoids and steroidal saponins were isolated. The present study continued the isolation and structure identification of the new potential compounds discovered based on UPLC-QTOF-MS/MS. By using silica gel, ODS, flash rapid preparation, and other column chromatography techniques, combined with prepared high performance liquid chromatography, five compounds were isolated from the 75% ethanol extract of the aerial parts of P. polyphylla var. chinensis, and their structures were identified by spectral data combined with chemical transformations, respectively, as(23S,25R)-23,27-dihydroxy-diosgenin-3-O-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→3)]-ß-D-glucopyranoside(1),(25R)-26-O-ß-D-glucopyranosyl-furost-5-en-3ß,22α,26-triol-3-O-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)]-ß-D-glucopyranoside(2),(25R)-27-O-ß-D-glucopyranosyl-5-en-3ß,27-dihydroxyspirost-3-O-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)]-ß-D-glucopyranoside(3),(25R)-27-O-ß-D-glucopyranosyl-5-en-3ß,27-dihydroxyspirost-3-O-α-L-rhamnopyranosyl-(1→2)-[ß-D-glucopyranosyl-(1→3)]-ß-D-glucopyranoside(4), and aculeatiside A(5). Among them, compounds 1-4 were new ones, and compound 5 was isolated from P. polyphylla var. chinensis for the first time.

[Separation and structural elucidation of C25 epimers of furostanol saponin from aerial parts of Paris polyphylla var. chinensis].

Paris polyphylla var. chinensis(PPC) is used as one of the origin plants of Paridis Rhizoma described in the Chinese Pharmacopoeia(2020 edition). Its resources shortage makes the planting scale gradually expand, and plenty of aerial parts are abandoned because of not being effectively used. On the basis of previous research, this study separated steroidal saponins to further clarify the chemical composition of the aerial parts of PPC. As a result, three pairs of 25R or 25S epimers of furostanol saponins were obtained by various column chromatography techniques. Their structures were identified as neosolanigroside Y6(1), solanigroside Y6(2), neoprotogracillin(3), protogracillin(4), neoprotodioscin(5) and protodioscin(6) by spectral data combining with chemical transformation. Compound 1 is a new compound, and compounds 2, 3 and 5 are isolated from Paris plants for the first time. Compounds 4 and 6 are isolated from this plant for the first time. Previously, only several spirostanol glycosides with 25S configuration were isolated from Paris plants. Guided by mass spectrometry, the present study isolated the furostanol saponins with 25S configuration from this genus for the first time, which further enriches the chemical information of Paris genus and provides a reference for the isolation of similar compounds.