Out of the Himalaya-Hengduan Mountains: Phylogenomics, biogeography and diversification of Polygonatum Mill. (Asparagaceae) in the Northern Hemisphere.

Clarifying the process of formation of diversity hotspots and the biogeographic connection between regions is critical in understanding the impact of environmental changes on organismal evolution. Polygonatum (Asparagaceae) is distributed across the Northern Hemisphere. It displays an uneven distribution, with more than 50% of its species occurring in the Himalaya-Hengduan Mountains (HHM). Here, we generated a time-calibrated phylogeny of Polygonatum, based on whole-plastome data, to reconstruct the genus' biogeographical history and morphological/chromosomal evolution. Our phylogenetic analyses strongly support the monophyly of Polygonatum and its division into three sections (i.e., Verticillata, Sibirica, and Polygonatum). Polygonatum originated from the HHM region during the early-Miocene (c. 20.10 Ma), and began to radiate since the mid-Miocene, driven by the uplift of the Qinghai-Tibet Plateau (QTP), increasingly colder/arid climates following the mid-Miocene Climatic Optimum (MMCO), and intensification of the East Asian winter monsoon. Dispersal from the HHM region to other regions was facilitated by the intensification of East Asian summer monsoon in response to global climatic warming during the MMCO. Decreasing dysploidy accompanied by karyotype change and polyploidization in Polygonatum appears to be associated with its diversification and colonization of new ecological niches. Our results highlight the importance of regional tectonic activities and past climatic changes from the Neogene onwards to the spatial-temporal diversification and distribution patterns of plant lineages with a wide distribution in the Northern Hemisphere. They also contribute to the knowledge of the uneven species richness between East Asia and other regions.

Dietary xylo-oligosaccharide ameliorates colonic mucus microbiota penetration with restored autophagy in interleukin-10 gene-deficient mice.

BACKGROUND: Inflammatory bowel disease (IBD) is, nowadays, highly prevalent and presents a global clinical challenge. The objective of this study is to assess the effects of xylo-oligosaccharide (XOS) on Il10-/- mice, a classic animal model of IBD. METHODS: Male wild-type (WT) mice were assigned to WT group, and Il10-/- mice were assigned to interleukin-10 gene-deficient (IL-10-KO) group and XOS group, respectively. There were 6-8 mice aged 8 weeks in each group. Mice in the XOS group received 1.0 g/kg/day XOS by gavage for 4 weeks. RESULTS: Compared with mice in IL-10-KO group, Il10-/- mice with XOS intervention presented significant mild spontaneous colitis with lower disease activity index, histological scores, and bowel inflammatory cytokine levels. Dietary XOS downregulated bowel mucus bacterial penetration, which occurred as early as the onset of bowel colitis. The effect of XOS was associated with restored expression of LC3II/I and decreased expression of p62 and beclin-1 in colon. CONCLUSIONS: Therefore, XOS decreases colonic mucus microbiota penetration with restored function of antophagy. Our findings suggest that XOS may be a potential dietary supplement or functional food for early management of IBD.