Multi-omics analyses provide insights into the genomic basis of differentiation among four sweet osmanthus groups.

Sweet osmanthus (Osmanthus fragrans) is famous in China for its flowers and contains four groups: Albus, Luteus, Aurantiacus, and Asiaticus. Understanding the relationships among these groups and the genetic mechanisms of flower color and aroma biosynthesis are of tremendous interest. In this study, we sequenced representative varieties from two of the four sweet osmanthus groups. Multi-omic and phylogenetic analyses of varieties from each of the four groups showed that Asiaticus split first within the species, followed by Aurantiacus and the sister groups Albus and Luteus. We show that the difference in flower color between Aurantiacus and the other three groups was caused by a 4-bp deletion in the promoter region of carotenoid cleavage dioxygenase 4 (OfCCD4) that leads to expression decrease. In addition, we identified 44 gene pairs exhibiting significant structural differences between the multi-seasonal flowering variety 'Rixianggui' in the Asiaticus group and other autumn flowering varieties. Through correlation analysis between intermediate products of aromatic components and gene expression, we identified eight genes associated with the linalool, α- and ß-ionone biosynthesis pathways. Overall, our study offers valuable genetic resources for sweet osmanthus, while also providing genetic clues for improving the flower color and multi-season flowering of osmanthus and other flowers.

Evaluation of the feeding safety of Moringa (Moringa oleifera L.) in the Sprague Dawley rat.

This study aimed to evaluate the safety of Moringa by comparing the effects of different gavage doses of Moringa. The general behavior, body weight, food intake, blood indexes, serum biochemical indexes, and histopathology of rats were used to determine the safety threshold and to provide a reference for the further development and use of Moringa as animal feed. 40 Sprague Dawley rats were selected and given transoral gavage for 28 consecutive days. The T1, T2 and T3 groups were observed for general behavior, body weight, and food intake. Blood and serum biochemical indices were quantified, and histopathology was performed to evaluate the effect and safety of Moringa. The results of the toxicological test showed that (1) Only T1 groups experienced diarrhea. (2) The body weight and food intake of rats in each group were normal compared with the control group. (3) The hematological and serum biochemical indices of rats in the T1 group were significantly different from those of CK but were in the normal range; (4) The results of microscopic examination of the heart, liver, spleen, lung, and kidney of rats in each group were normal, but inflammation occurred in stomach and jejunum of rats in the T1 group, but not in the ileum. The gastrointestinal tract of rats in the T2 and T3 groups were normal. (5) No abnormal death occurred in any of the treatment groups.The results of this study revealed that gavage of Moringa homogenate at a dose of 6 g/kg BW can cause diarrhea in rats. Although there is no pathological effect on weight, food intake, blood and serum biochemical indicators in rats, there are pathological textures in the gastrointestinal tissue caused by diarrhea. Therefore, the safety threshold of Moringa homogenate should be ≤ 3 g/kg BW.

A new mechanism of flowering regulation by the competition of isoforms in Osmanthus fragrans.

The regulation of flowering time is typically governed by transcription factors or epigenetic modifications. Transcript isoforms can play important roles in flowering regulation. Recently, transcript isoforms were discovered in the key genes, OfAP1 and OfTFL1, of the flowering regulatory network in Osmanthus fragrans. OfAP1-b generates a full-length isoform of OfAP1-b1 as well as an isoform of OfAP1-b2 that lacks the C-terminal domain. Although OfAP1-b2 does not possess an activation domain, it has a complete K domain that allows it to form heterodimers. OfAP1-b2 competes with OfAP1-b1 by binding with OfAGL24 to create non-functional and functional heterodimers. As a result, OfAP1-b1 promotes flowering while OfAP1-b2 delays flowering. OfTFL1 produces two isoforms located in different areas: OfTFL1-1 in the cytoplasm and OfTFL1-2 in the nucleus. When combined with OfFD, OfTFL1-1 does not enter the nucleus to repress AP1 expression, leading to early flowering. Conversely, when combined with OfFD, OfTFL1-2 enters the nucleus to repress AP1 expression, resulting in later flowering. Tissue-specific expression and functional conservation testing of OfAP1 and OfTFL1 support the new model's effectiveness in regulating flowering. Overall, this study provides new insights into regulating flowering time by the competition of isoforms.