Molecular analyses display the increasing diversity of Podostemaceae in China.

•Four newly recorded species of Podostemaceae from southern China were identified by molecular and morphological evidence.•17 plastomes of Podostemaceae were newly sequenced and two novel polymorphic barcodes (ccsA and ndhA) detected.•Our findings reveal greater species richness (15 species from five genera) of Podostemaceae in China and supply molecular resources for research on taxonomy and phylogenomics of this enigmatic aquatic family.

Resurrection of Perilimnastes (Sonerileae, Melastomataceae) with description of a new species P.nana.

Recent research has indicated that the Phyllagathis (raphides) clade (Sonerileae, Melastomataceae) is only distantly related to the type of Phyllagathis and should be separated as a distinct genus. Phylogeny of this clade is here reconstructed with expanded taxon sampling. Four strongly supported subclades have been identified. The possible affinities of taxa that were not sampled in the analysis are discussed, based on morphological data. Perilimnastes is resurrected as the generic name of the Phyllagathis (raphides) clade. A generic description, colour figures, map of distribution, a list of included species and a key are provided for Perilimnastes. Fifteen new combinations are made plus the description of a new species. As interpreted here, Perilimnastes consists of twenty species and two varieties.

Phylogenomics of the aquatic plant genus Ottelia (Hydrocharitaceae): Implications for historical biogeography.

Ottelia Pers. is the second largest genus of the family Hydrocharitaceae, including approximately 23 extant species. The genus exhibits a diversity of both bisexual and unisexual flowers, and complex reproductive system comprising cross-pollinated to cleistogamous flowers. Ottelia has been regarded as a pivotal group to study the evolution of Hydrocharitaceae, but the phylogenic relationships and evolutionary history of the genus remain unresolved. Here, we reconstructed a robust phylogenetic framework for Ottelia using 40 newly assembled complete plastomes. Our results resolved Ottelia as a monophyletic genus consisting of two major clades, which correspond to the main two centers of diversity in Asia and Africa. According to the divergence time estimation analysis, the crown group Ottelia began to diversify around 13.09 Ma during the middle Miocene. The biogeographical analysis indicated the existence of the most recent common ancestor somewhere in Africa/Australasia/Asia. Basing on further insights from the morphological evolution of Ottelia, we hypothesized that the ancestral center of origin was in Africa, from where the range expanded by transoceanic dispersal to South America and Australasia, and further from Australasia to Asia. We suggested that the climatic change and global cooling since the mid-Miocene, such as the development of East Asian monsoon climate and tectonic movement of the Yunnan-Guizhou Plateau (YGP), might have played a crucial role in the evolution of Ottelia in China.

Ubiquitin-specific protease 49 attenuates IL-1ß-induced rat primary chondrocyte apoptosis by facilitating Axin deubiquitination and subsequent Wnt/ß-catenin signaling cascade inhibition.

Osteoarthritis (OA) is an age-related chronic joint degenerative disease. Interleukin 1 beta (IL-1ß) is considered a marker for the progression of OA. In this study, we found that Ubiquitin-Specific Peptidase 49 (USP49) was significantly less expressed in OA patients compared with healthy individuals. Treating primary rat chondrocytes with different concentrations of IL-1ß resulted in decreased Usp49 expression, while Usp49 overexpression could attenuate IL-1ß-induced chondrocyte apoptosis by promoting Axin deubiquitination. The deubiquitination of Axin led to the accumulation of the protein, which in turn resulted in ß-catenin degradation and Wnt/ß-catenin signaling cascade inhibition. Interestingly, we also found that [6]-gingerol, an anti-OA drug, could upregulate the protein level of Usp49 and suppress the Wnt/ß-catenin signaling cascade in primary rat chondrocytes. Taken together, our study not only demonstrates that Usp49 can negatively regulate the progression of OA by inhibiting the Wnt/ß-catenin signaling cascade, but also elucidates the underlying molecular mechanisms.

Ottelia fengshanensis, a new bisexual species of Ottelia (Hydrocharitaceae) from southwestern China.

Ottelia fengshanensis, a new species (Hydrocharitaceae) from southwest China is here described and illustrated. Comparing its morphological features to putative close relatives O. guanyangensis, it has 3-4 flowers (vs. 2-5) each spathe, hexagonal-cylindric fruit, white styles (vs. yellow), green leaves (vs. dark green) and fruit tiny winged (vs. winged obviously). Molecular phylogenetic investigation of four DNA sequences (ITS, rbcL, trnK5' intron and trnS-trnG) and the Poisson Tree Processes model for species delimitation (PTP) analysis, further resolves O. fengshanensis as a new species that is close to O. guanyangensis with distinct support.