Dryopterisjinpingensis, a critically endangered diploid new species of Dryopteridaceae from Yunnan, China.

Dryopterisjinpingensis, a new species of diploid, sexually reproductive ferns of Dryopteridaceae from Yunnan, southwestern China, is described and illustrated. Morphologically, D.jinpingensis is similar to D.gaoligongensis but unique in elongated lanceolate laminae, sessile or subsessile pinna stalks, and overlapping membranous scales adnate to stipe base. Phylogenetic analyses based on both plastome and the nuclear AK1 gene sequences showed that D.jinpingensis is sister to D.gaoligongensis. A detailed taxonomic description with line drawings is provided, and its conservation status is evaluated to be critically endangered.

Anthropogenic disturbance driving population decline of a dominant tree in East Asia evergreen broadleaved forests over the last 11,000 years.

Current biodiversity loss is generally considered to have been caused by anthropogenic disturbance, but it is unclear when anthropogenic activities began to affect biodiversity loss. One hypothesis suggests it began with the Industrial Revolution, whereas others propose that anthropogenic disturbance has been associated with biodiversity decline since the early Holocene. To test these hypotheses, we examined the unique vegetation of evergreen broadleaved forests (EBLFs) in East Asia, where humans have affected landscapes since the early Holocene. We adopted a genomic approach to infer the demographic history of a dominant tree (Litsea elongata) of EBLFs. We used Holocene temperature and anthropogenic disturbance factors to calculate the correlation between these variables and the historical effective population size of L. elongata with Spearman statistics and integrated the maximum-entropy niche model to determine the impact of climate change and anthropogenic disturbance on fluctuation in its effective population size. We identified 9 well-defined geographic clades for the populations of L. elongata. Based on the estimated historical population sizes of these clades, all the populations contracted, indicating persistent population decline over the last 11,000 years. Demographic history of L. elongata and human population change, change in cropland use, and change in irrigated rice area were significantly negatively correlated, whereas climate change in the Holocene was not correlated with demographic history. Our results support the early human impact hypothesis and provide comprehensive evidence that early anthropogenic disturbance may contribute to the current biodiversity crisis in East Asia.

Primulinajiulianshanensis, a new species of Gesneriaceae from Jiangxi Province, China.

Primulinajiulianshanensis F.Wen & G.L.Xu, a new species of Gesneriaceae from Jiulianshan National Nature Reserve of Jiangxi Province, China, is described and illustrated here. Molecular evidence showed it was sister to P.wenii Jian Li & L.J.Yan, while the morphological observation found clear differences between them, petiole, both sides of leaf blades, adaxial surface of the calyx lobes, corolla inside toward the bottom, bract margins covered glandular-pubescent hairs in P.jiulianshanensis (vs. no glandular-pubescent hairs in P.wenii); lateral bracts 4-9 × ca. 2 mm, the central one 2-5 × 1-1.5 mm, adaxially glabrous but sparsely pubescent at apex (vs. lateral bracts 14-16 × 2.5-3.0 mm, the central one 10-12 × 1.3-1.6 mm, all adaxially pubescent); calyx lobes 8-11 × ca. 2 mm, each side with several brown serrate teeth at apex (vs. 14-15 × ca. 2.5 mm, margin entire); filaments and staminodes sparsely yellow glandular-puberulent (vs. white, glabrous).

Phylogenomic insights into the origin and evolutionary history of evergreen broadleaved forests in East Asia under Cenozoic climate change.

The evergreen versus deciduous leaf habit is an important functional trait for adaptation of forest trees and has been hypothesized to be related to the evolutionary processes of the component species under paleoclimatic change, and potentially reflected in the dynamic history of evergreen broadleaved forests (EBLFs) in East Asia. However, knowledge about the shift of evergreen versus deciduous leaf with the impact of paleoclimatic change using genomic data remains rare. Here, we focus on the Litsea complex (Lauraceae), a key lineage with dominant species of EBLFs, to gain insights into how evergreen versus deciduous trait shifted, providing insights into the origin and historical dynamics of EBLFs in East Asia under Cenozoic climate change. We reconstructed a robust phylogeny of the Litsea complex using genome-wide single-nucleotide variants (SNVs) with eight clades resolved. Fossil-calibrated analyses, diversification rate shifts, ancestral habit, ecological niche modelling and climate niche reconstruction were employed to estimate its origin and diversification pattern. Taking into account studies on other plant lineages dominating EBLFs of East Asia, it was revealed that the prototype of EBLFs in East Asia probably emerged in the Early Eocene (55-50 million years ago [Ma]), facilitated by the greenhouse warming. As a response to the cooling and drying climate in the Middle to Late Eocene (48-38 Ma), deciduous habits were evolved in the dominant lineages of the EBLFs in East Asia. Up to the Early Miocene (23 Ma), the prevailing of East Asian monsoon increased the extreme seasonal precipitation and accelerated the emergence of evergreen habits of the dominant lineages, and ultimately shaped the vegetation resembling that of today.

Plastome phylogenomic analysis reveals evolutionary divergences of Polypodiales suborder Dennstaedtiineae.

BACKGROUND: Polypodiales suborder Dennstaedtiineae contain a single family Dennstaedtiaceae, eleven genera, and about 270 species, and include some groups that were previously placed in Dennstaedtiaceae, Hypolepidaceae, Monachosoraceae, and Pteridaceae. The classification and phylogenetic relationships among these eleven genera have been poorly understood. To explore the deep relationships within suborder Dennstaedtiineae and estimate the early diversification of this morphologically heterogeneous group, we analyzed complete plastomes of 57 samples representing all eleven genera of suborder Dennstaedtiineae using maximum likelihood and Bayesian inference. RESULTS: The phylogenetic relationships of all the lineages in the bracken fern family Dennstaedtiaceae were well resolved with strong support values. All six genera of Hypolepidoideae were recovered as forming a monophyletic group with full support, and Pteridium was fully supported as sister to all the other genera in Hypolepidoideae. Dennstaedtioideae (Dennstaedtia s.l.) fell into four clades with full support: the Microlepia clade, the northern Dennstaedtia clade, the Dennstaedtia globulifera clade, and the Dennstaedtia s.s. clade. Monachosorum was strongly resolved as sister to all the remaining genera of suborder Dennstaedtiineae. Based on the well resolved relationships among genera, the divergence between Monachosorum and other groups of suborder Dennstaedtiineae was estimated to have occurred in the Early Cretaceous, and all extant genera (and clades) in Dennstaedtiineae, were inferred to have diversified since the Late Oligocene. CONCLUSION: This study supports reinstating a previously published family Monachosoraceae as a segregate from Dennstaedtiaceae, based on unique morphological evidence, the shady habitat, and the deep evolutionary divergence from its closest relatives.

Structural Variation of Plastomes Provides Key Insight Into the Deep Phylogeny of Ferns.

Structural variation of plastid genomes (plastomes), particularly large inversions and gene losses, can provide key evidence for the deep phylogeny of plants. In this study, we investigated the structural variation of fern plastomes in a phylogenetic context. A total of 127 plastomes representing all 50 recognized families and 11 orders of ferns were sampled, making it the most comprehensive plastomic analysis of fern lineages to date. The samples included 42 novel plastomes of 15 families with a focus on Hymenophyllales and Gleicheniales. We reconstructed a well-supported phylogeny of all extant fern families, detected significant structural synapomorphies, including 9 large inversions, 7 invert repeat region (IR) boundary shifts, 10 protein-coding gene losses, 7 tRNA gene losses or anticodon changes, and 19 codon indels (insertions or deletions) across the deep phylogeny of ferns, particularly on the backbone nodes. The newly identified inversion V5, together with the newly inferred expansion of the IR boundary R5, can be identified as a synapomorphy of a clade composed of Dipteridaceae, Matoniaceae, Schizaeales, and the core leptosporangiates, while a unique inversion V4, together with an expansion of the IR boundary R4, was verified as a synapomorphy of Gleicheniaceae. This structural evidence is in support of our phylogenetic inference, thus providing key insight into the paraphyly of Gleicheniales. The inversions of V5 and V7 together filled the crucial gap regarding how the "reversed" gene orientation in the IR region characterized by most extant ferns (Schizaeales and the core leptosporangiates) evolved from the inferred ancestral type as retained in Equisetales and Osmundales. The tRNA genes trnR-ACG and trnM-CAU were assumed to be relicts of the early-divergent fern lineages but intact in most Polypodiales, particularly in eupolypods; and the loss of the tRNA genes trnR-CCG, trnV-UAC, and trnR-UCU in fern plastomes was much more prevalent than previously thought. We also identified several codon indels in protein-coding genes within the core leptosporangiates, which may be identified as synapomorphies of specific families or higher ranks. This study provides an empirical case of integrating structural and sequence information of plastomes to resolve deep phylogeny of plants.

A revision of Dryopteris sect. Diclisodon (Dryopteridaceae) based on morphological and molecular evidence with description of a new species.

Dryopteris sect. Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia. Here, we carried out morphological and phylogenetic analyses of this section. A new species from southwest China, D. gaoligongensis, is described and illustrated. Dryopteris gaoligongensis resembles D. indonesiana and D. sparsa, but differs by having a creeping rhizome and large 4-pinnate fronds. We also show that D. glabrior Ching & Z.Y. Liu is a distinct species; however, because it is a later homonym of D. glabrior Copel., it should be renamed D. renchangiana. We conclude that a species previously known as D. nitidula , also an illegitimate homonym, should be recognized with a new name, D. sinonepalensis. We resolve the phylogenetic position of D. yoroii as sister to other sampled species of D. sect. Diclisodon. Our phylogenetic analyses confirm the distinctiveness of D. gaoligongensis, D. renchangiana, and D. sinonepalensis. A key to species of D. sect. Diclisodon in China is provided.

Target-Based Virtual Screening and LC/MS-Guided Isolation Procedure for Identifying Phloroglucinol-Terpenoid Inhibitors of SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to more than 5 million deaths worldwide to date. Due to the limited therapeutic options so far available, target-based virtual screening with LC/MS support was applied to identify the novel and high-content compounds 1-4 with inhibitory effects on SARS-CoV-2 in Vero E6 cells from the plant Dryopteris wallichiana. These compounds were also evaluated against SARS-CoV-2 in Calu-3 cells and showed unambiguous inhibitory activity. The inhibition assay of targets showed that compounds 3 and 4 mainly inhibited SARS-CoV-2 3CLpro, with effective Kd values. Through docking and molecular dynamics modeling, the binding site is described, providing a comprehensive understanding of 3CLpro and interactions for 3, including hydrogen bonds, hydrophobic bonds, and the spatial occupation of the B ring. Compounds 3 and 4 represent new, potential lead compounds for the development of anti-SARS-CoV-2 drugs. This study has led to the development of a target-based virtual screening method for exploring the potency of natural products and for identifying natural bioactive compounds for possible COVID-19 treatment.

A phylogenetic and morphological study of the Tectariafuscipes group (Tectariaceae), with description of a new species.

The fern species Tectariafuscipes and morphologically similar species, which are common in tropical and subtropical mainland Asia, constitute a taxonomically confusing group. To better understand species boundaries and relationships within the T.fuscipes group, we conducted phylogenetic analyses of five plastid regions and morphological observations of herbarium specimens and living plants. As a result, we produced a generally well-resolved phylogeny of the T.fuscipes group and related species in Asia. The phylogenetic analyses supported the monophyly of the T.fuscipes group, which includes T.dissecta, T.fuscipes, T.ingens, T.paradoxa, T.setulosa, T.subfuscipes, T.subsageniacea and a new species, but excludes T.kusukusensis. However, T.fuscipes, T.subfuscipes and T.subsageniacea are almost indistinguishable in morphology, which form a complex characterised by the black linear-lanceolate stipe scales. The new species found in southern China and Vietnam is described here as T.fungii. It is similar to the T.fuscipes complex and T.kusukusensis, but differs from the former mainly by its brown-castaneous lanceolate stipe scales and from the latter by having nearly hairless laminae (versus frond axes abaxially bearing copious hairs).

Design, synthesis, antitumor activity and theoretical calculation of novel PI3Ka inhibitors.

PI3Kα has been identified as an ideal target to treat with PIK3CA gene mutation disease, including drugs such as Alpelisib and Copanlisib. Five purine analogues and four thiazole analogues were designed and synthesized. Their enzymaticactivity against PI3Ka/ß/γ/δ were tested, respectively. All compounds showed excellent selectivity in modulating PI3Ka activity, and parts of the compounds showed good inhibition. Meanwhile, we used Autodock 4.2 to explore the binding mode of the most potential compound Tg with the target protein. In addition, DFT was used to calculate the HOMO-LUMO maps of the compounds Tf, Tg and positive control. This paper will provide some useful information for further drug design of PI3Kα inhibitors.

Correction: Functional human 3D microvascular networks on a chip to study the procoagulant effects of ambient fine particulate matter.

[This corrects the article DOI: 10.1039/C7RA11357A.].

New Species of the Fern Genus Lindsaea (Lindsaeaceae) from New Guinea with Notes on the Phylogeny of L. sect. Synaphlebium.

To determine the taxonomic identities and the systematic positions of some collections of Lindsaea sect. Synaphlebium (Lindsaeaceae) from Papua New Guinea, we conducted morphological comparisons and phylogenetic analyses on the whole section. A total of 22 morphological characters were selected and coded for each of all known taxa in L. sect. Synaphlebium, and were analyzed using maximum parsimony. The datasets containing either of or combined two plastid DNA sequences (trnL-trnF spacer and trnH-psbA spacer) of 37 taxa were analyzed using maximum parsimony, maximum likelihood, and Bayesian inference. Morphological comparisons revealed two new species which are formally published here as L. subobscura and L. novoguineensis. Lindsaea subobscura is similar to sympatric L. obscura and L. modesta but differs in the obviously reduced upper pinnules and other characters. Lindsaea novoguineensis is most similar to L. pacifica from Melanesia but differs in having rhomboid pinnules with truncate apices and concave soral receptacles. Molecular analyses resolved L. sect. Synaphlebium and allied species into five well-supported clades, namely L. rigida clade, L. obtusa clade, L. pulchella clade, L. multisora clade, and L. cultrata clade. The new species L. novoguineensis is included in L. obtusa clade; L. subobscura is in L. pulchella clade; whereas the majority of L. sect. Synaphlebium is clustered in L. cultrata clade. As the section Synaphlebium sensu Kramer is strongly suggested as polyphyletic, we propose the concept of a monophyletic L. sect. Synaphlebium in a broad sense that comprises five lineages. The morphological circumscription of L. sect. Synaphlebium sensu lato and the divergence in morphology, habit, and distribution between the five lineages are briefly discussed. Further molecular study is needed to test the systematic positions of 16 other species which are supposed to be within L. sect. Synaphlebium sensu lato but have not been included in this and previous molecular analyses.