Adaptation to cool climates has occurred several times in different angiosperm groups. Among them, Pooideae, the largest grass subfamily with ∼3,900 species including wheat and barley, have successfully occupied many temperate regions and play a prominent role in temperate ecosystems. To investigate possible factors contributing to Pooideae adaptive evolution to cooling climates, we performed phylogenetic reconstruction using five gene sets (with 1,234 nuclear genes and their subsets) from 157 transcriptomes/genomes representing all 15 tribes and 24 of 26 subtribes. Our phylogeny supports the monophyly of all tribes (except Diarrheneae) and all subtribes with at least two species, with strongly supported resolution of their relationships. Molecular dating suggests that Pooideae originated in the late Cretaceous, with subsequent divergences under cooling conditions first among many tribes from the early middle to late Eocene and again among genera in the middle Miocene and later periods. We identified a cluster of gene duplications (CGD5) shared by the core Pooideae (with 80% Pooideae species) near the Eocene-Oligocene transition, coinciding with the transition from closed to open habitat and an upshift of diversification rate. Molecular evolutionary analyses homologs of CBF for cold resistance uncovered tandem duplications during the core Pooideae history, dramatically increasing their copy number and possibly promoting adaptation to cold habitats. Moreover, duplication of AP1/FUL-like genes before the Pooideae origin might have facilitated the regulation of the vernalization pathway under cold environments. These and other results provide new insights into factors that likely have contributed to the successful adaptation of Pooideae members to temperate regions.
Parkinson's disease (PD) is the second most common neurodegenerative disease affecting millions of elder people due to the degeneration of dopamine neurons in the striatum and substantia nigra. The clinical manifestations of PD include tremor, rigidity, bradykinesia and postural instability. Studying PD is challenging due to two obstacles: 1) disease models such as primary neurons or animal models usually couldn't recapitulate the disease phenotype, and 2) accessibility of human autopsied brain samples is very limited if not impossible. Induced pluripotent stem cells (iPSCs)-derived neuronal cells from patients emerge as an ideal in vitro model for disease modeling and drug development. Here we describe a cell density-dependent method for preparing functional hiPSC-derived dopamine neurons (iDAs) with ~90% purity (TH-positive cells). iDAs derived from PD patient exhibit the disease-related phenotypes, for example, slowed morphogenesis, reduced dopamine release, impaired mitochondrial function, and α-synuclein accumulation as early as 35 days after induction. Furthermore, we found that the effects of cell density are different between iDA development stages, whereas high cell density increases stress for early neural progenitor cells (NPCs), but are neural-protective for mature iDAs, high density also favors morphogenesis. Hence, using stage and density-dependent strategies we can obtain high quality iDAs, which are critical for disease modeling, drug development and cell replacement therapy.
Femtosecond laser corneal refractive surgery is generally considered safe and effective; however, this procedure is rarely associated with severe allergic reactions. We reported a rare case of hypersensitivity reactions which caused bilateral peripheral corneal infiltrates after femtosecond laser small incision lenticule (SMILE) surgery in a man with a history of fruits allergy.Here we report the case of a young man who developed white, ring-shaped bilateral peripheral infiltrates that appeared 1 day after an uneventful SMILE surgery. The overlying corneal epithelium was intact; the infiltrate was negative for bacterial culture, but high titers of immunoglobulin E was demonstrated in the blood. Symptomatically, a clinical diagnosis of sterile corneal infiltrates was made, and the patient was treated with topical and systemic steroids. The infiltrates were immunogenic in origin, which may be caused by the contact lenses used for suction duration in surgery. It resolved without corneal scarring in the subsequent months following steroid treatment. The patient's visual acuity improved.When patients with a history of allergy who aim to perform corneal refractive surgery, surgeons must consider possible hypersensitivity reactions after treatment. More studies are needed to clarify the relationship between contact glass used in femtosecond laser corneal refractive surgery and IgE mediated hypersensitivity reactions.
A new guaiane-type sesquiterpene glycoside, torilolone 8-O-beta-D-glucopyranoside (1), together with a known analogue compound, torilolone 11-O-beta-D-glucopyranoside (2), was isolated from the fruits of Daucus carota L. Their chemical structures were elucidated on the basis of MS, NMR spectroscopic analyses coupled with chemical degradation. The cytotoxic activities of two isolated compounds were evaluated against two human gastric cancer cell lines BGC-823 and AGS using MTT assay.
Aristolochia weixiensis, a new species from northwest Yunnan, China, is described. A. weixiensis is affinis to A. moupinensis with similar leaf shape, but differs from the latter in the limb with dark purple colour and dense papillae, ca. 3.5 cm in diam., throat with light brown colour and dense brownish red patches, 13–16 mm in diam. Meanwhile, A. weixiensis is similar to A. wuana with similar leaves in shape, but differs in fruit and the size of leaf.
Aiming at the hydraulic problems existing in the operation of the two lakes in the east route of the South-to-North Water Diversion Project, a one-dimensional hydraulic equation and a pump station performance equation were coupled. Based on the Fortran language, a simulation model for water delivery scheduling of the two-lake cascade pumping stations was developed and combined with the actual measurement from 2013 to 2017. The data has been calibrated for the model, which can simulate the hydraulics of different water transport conditions. Based on the hydraulics method, the hydraulic loss under normal water conveyance conditions between channels was analyzed, calculated and studied. In view of the aquatic problem, Changgou-Denglou section was selected as the research object, and the model was combined based on the measured data. The hydraulic loss under the plugging condition of the aquatic plant was analyzed and calculated and the law was studied. Based on the water balance method, the water loss in the two lakes was analyzed and calculated. The research results can provide reference for the operation of the two lakes in the east route of the South-to-North Water Diversion Project.
Supported by remote sensing and geography information systems, the land use patterns of riparian zones of Bielahong River in the Sanjiang Plain were analyzed using TM imageries in 1986, 1995, 2000 and 2006. The influence of human activities on the land use patterns of riparian zones of Bielahong River were investigated too. The results showed that in the riparian zone of Bielahong River, farmlands were mainly distributed beyond the distance of 2 km from the river, while marshes were within the riparian zone of 1 km from the river; forest lands were concentrated in the the riparian zones of 1-8 km from the river. From 1986 to 2006, within the riparian zone of 1 km from the river marshes were relatively remained intact, but in the riparian zones of Bielahong River of 1-8 km from the river, the impact of human activities turned to be intensive. During 2000-2006, the impact of human activities in the riparian zones was increasing and moving forwards to the river, by reclaiming marshes, grass lands and forest lands into farmlands. It harmed wetland ecosystem in the riparian zones of Bielahong River. More attention should be paid to the protection of riparian zones of Bielahong River of 1-2 km from the river.
The rice blast resistance gene Pi54 was cloned from Oryza sativa ssp. indica cv. Tetep, which conferred broad-spectrum resistance against Magnaporthe oryzae. Pi54 allelic variants have been identified in not only domesticates but also wild rice species, but the majority of japonica and some indica cultivars lost the function. We here found that Pi54 (Os11g0639100) and its homolog Os11g0640600 (named as #11) were closely located on a 25 kbp region in japonica cv. Sasanishiki compared to a 99 kbp region in japonica cv. Nipponbare. Sasanishiki lost at least six genes containing one other R-gene cluster (Os11g0639600, Os11g0640000, and Os11g0640300). Eight AA-genome species including five wild rice species were classified into either Nipponbare or Sasanishiki type. The BB-genome wild rice species O. punctata was Sasanishiki type. The FF-genome wild rice species O. brachyantha (the basal lineage of Oryza) was neither, because Pi54 was absent and the orientation of the R-gene cluster was reversed in comparison with Nipponbare-type species. The phylogenetic analysis showed that #11gene of O. brachyantha was on the root of both Pi54 and #11 alleles. All Nipponbare-type Pi54 alleles were specifically disrupted by 143 and 37/44 bp insertions compared to Tetep and Sasanishiki type. In addition, Pi54 of japonica cv. Sasanishiki lost nucleotide-binding site and leucine-rich repeat (NBS–LRR) domains owing to additional mutations. These results suggest that Pi54 might be derived from a tandem duplication of the ancestor #11 gene in progenitor FF-genome species. Two divergent structures of Pi54 locus caused by a mobile unit containing the nearby R-gene cluster could be developed before domestication. This study provides a potential genetic resource of rice breeding for blast resistance in modern cultivars sustainability.
With the advance of sequencing technology, the number of sequenced genomes has been rapidly increasing. However, the functions of a large number of genes, including gene families with domains of unknown functions (DUF), still remain unclear. In this study, we analysed eight members of OsDUF617 (OsDUF617.1-OsDUF617.8) in rice Nipponbare. By phylogenetic analysis, all these OsDUF617 proteins could be classified into three major groups (I, II, III). We used real-time polymerase chain reaction to examine the expression of all these OsDUF617 members in 15 distinct rice tissues. The expression of these members under various abiotic stress and abscisic acid (ABA) conditions was also examined. Under drought conditions, the expression level of OsDUF617.8 in rice was significantly elevated. Overexpression of OsDUF617.8 in Escherichia coli led to a significant enhancement of catalase (CAT) and peroxidase (POD) activities, and improved bacterial resistance to osmotic stress. The results of this study will provide important information for further study of the function of the OsDUF617 family in rice.Supplemental data for this article is available online at 10.1080/13102818.2021.1934541.
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