莫古礼(Floyd Alonzo McClure)在华采集和引种竹类植物的历史及其影响

竹类植物是美国采集者在我国采集和引种的一类主要植物。在众多的竹类植物采集者中, 莫古礼(Floyd Alonzo McClure)是最具代表性的一位, 他于1919-1940年在岭南大学开展竹类植物研究, 在此期间多次采集竹类植物标本并引种竹类植物到美国。本研究通过大量文献研究、档案查阅以及实地调研, 整理了莫古礼采集竹类植物的路线和采集地, 并对竹类植物学名进行校对, 分析了莫古礼在华研究、采集和引种竹类植物的历史及其影响。经统计, 莫古礼在华期间竹类植物标本采集地涉及12个省级行政区39个地级市, 主要集中在广东、海南、香港等地; 引种地涉及9个省级行政区的25个地级市; 共采集竹类植物标本727号1,840份, 隶属20属93种(含种下单位, 下同), 分别占我国竹类植物属和种的58.8%和17.4%; 共引种竹类植物255份, 隶属于17属77种, 分别占我国竹类植物属和种的50.0%和14.4%。莫古礼在华采集和引种竹类植物极大地发展了竹类植物分类学, 所采集的竹类植物标本为后人竹类植物研究提供了极大的帮助, 所引种的竹类植物极大丰富了美国竹类植物种类, 也促进了竹类植物在美国的应用。     

Antibiotic activity of lectins from marine algae against marine vibrios

Saline and aqueous ethanol extracts of marine algae and the lectins from two red algal species were assayed for their antibiotic activity against marine vibrios. Experimental studies were also carried out on the influence of environmental factors on such activity, using batch cultures. The results indicated that many of the saline extracts of the algal species were active and that the activity was selective against those vibrios assayed. The algal extracts were active against Vibrio pelagius and the fish pathogen V. vulnificus, but inactive against V. neresis. Algal lectins from Eucheuma serra (ESA) and Galaxaura marginata (GMA) strongly inhibited V. vulnificus but were inactive against the other two vibrios. The antibacterial activity of algal extracts was inhibited by pretreatment with various sugars and glycoprotein. Extracts of the two red algae, E. serra and Pterocladia capillacea, in saline and aqueous ethanol, inhibited markedly the growth rate of V. vulnificus at very low concentrations. Culture results indicated that metabolites active against V. vulnificus were invariably produced in P. capillacea over a wide range of temperature, light intensity, and nutritional conditions. Enhanced antibacterial activity occurred when P. capillacea was grown under higher irradiance, severe nutrient stress and moderate temperature (20 °C), reflecting the specific antibiotic characteristics of this alga. The strong antibiotic activity of lectins towards fish pathogenic bacteria reveals one of the important roles played by algal lectins, as well as the potential high economic value of those marine algae assayed for aquaculture and for biomedical purposes.     

Progress in melanoma treatment: Patient's perspectives

Upon the 20th Anniversary of the Society for Melanoma Research, we highlight the perspectives of patients aiming to help improve future experiences, outcomes, and their quality of life over the next 20 years. Five melanoma patients generously shared their inspiring and enlightening stories of diagnosis, treatment, and outcomes. Many patients had excellent medical teams that synergistically worked together to provide an accurate diagnosis, effective treatment options, and supportive care. However, it is clear that health inequities persist in communities where people of color are predominant, affecting early detection, patient experience, and outcomes. These stories shed light on the unique challenges faced by patients and how the lack of melanoma awareness and adequate resources, especially in communities of color or low socioeconomic status, can contribute to disparate outcomes in melanoma care. We expect that these stories will raise awareness about the progress in melanoma treatment but also the existent disparities in melanoma diagnosis and treatment and the importance of early detection and prevention.     

From forest to farmland: pollen‐inferred land cover change across Europe using the pseudobiomization approach

Maps of continental‐scale land cover are utilized by a range of diverse users but whilst a range of products exist that describe present and recent land cover in Europe, there are currently no datasets that describe past variations over long time‐scales. User groups with an interest in past land cover include the climate modelling community, socio‐ecological historians and earth system scientists. Europe is one of the continents with the longest histories of land conversion from forest to farmland, thus understanding land cover change in this area is globally significant. This study applies the pseudobiomization method (PBM) to 982 pollen records from across Europe, taken from the European Pollen Database (EPD) to produce a first synthesis of pan‐European land cover change for the period 9000 bp to present, in contiguous 200 year time intervals. The PBM transforms pollen proportions from each site to one of eight land cover classes (LCCs) that are directly comparable to the CORINE land cover classification. The proportion of LCCs represented in each time window provides a spatially aggregated record of land cover change for temperate and northern Europe, and for a series of case study regions (western France, the western Alps, and the Czech Republic and Slovakia). At the European scale, the impact of Neolithic food producing economies appear to be detectable from 6000 bp through reduction in broad‐leaf forests resulting from human land use activities such as forest clearance. Total forest cover at a pan‐European scale moved outside the range of previous background variability from 4000 bp onwards. From 2200 bp land cover change intensified, and the broad pattern of land cover for preindustrial Europe was established by 1000 bp . Recognizing the timing of anthropogenic land cover change in Europe will further the understanding of land cover‐climate interactions, and the origins of the modern cultural landscape.     

Evidence for an Adenovirus Type 2-Coded Early Glycoprotein

We have identified an adenovirus type 2 (Ad2)-induced early glycopolypeptide with an apparent molecular weight of 20,000 to 21,000 (20/21K), as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The 20/21K polypeptide could be labeled in vivo with [(3)H]glucosamine. [(35)S]methionine- and [(3)H]-glucosamine-labeled 20/21K polypeptides bound to concanavalin A-Sepharose columns and were eluted with 0.2 M methyl-alpha-d-mannoside. The pulse-labeled polypeptide appeared as a sharp band with an apparent molecular weight of 21K, but after a chase it converted to multiple bands with an average molecular weight of 20K. This variability in electrophoretic mobility is consistent with glycosylation or deglycosylation of the 20/21K polypeptide. Analysis of the pulse and pulse-chase-labeled forms by using partial proteolysis indicated that the polypeptides were highly related chemically, but not identical. Most of the 20/21K polypeptide is localized in the cytoplasm fraction of infected cells lysed by Nonidet P-40. The 20/21K polypeptide and a 44K polypeptide, labeled with [(35)S]methionine or [(3)H]glucosamine in Ad2-infected human cells, were precipitated by a rat antiserum against an Ad2-transformed rat cell line (T2C4), but not by antisera against three other Ad2-transformed rat cell lines, or by serum from nonimmune rats. The partial proteolysis patterns of the 20/21K and the 44K polypeptides were indistinguishable, indicating that the two polypeptides are highly related, and suggesting that the 44K polypeptide might be a dimer of the 20/21K polypeptide. The 20/21K polypeptide was also induced in Ad2-early infected monkey and hamster cells. These results imply that the 20/21K polypeptide is synthesized in Ad2-infected human, monkey, and hamster cells, and in one but not all Ad2-transformed rat cells. Thus, the 20/21K polypeptide is probably viral coded rather than cell coded and viral induced.     

Expression of an Oncidium gene encoding a patatin-like protein delays flowering in Arabidopsis by reducing gibberellin synthesis

The involvement of lipase in flowering is seldom studied, and this research provides evidence that fatty acids produced by lipase affect flowering. OSAG78 encoding a patatin-like protein was isolated from Oncidium Gower Ramsey. OSAG78 fused with green fluorescent protein was found to localize at the cell membrane. Transgenic Arabidopsis overexpressing OSAG78 demonstrated higher lipase activity than the wild-type control. In addition, the amount of free linoleic acid and linolenic acid in transgenic Arabidopsis was found to be higher than that in the wild type. Transgenics overexpressing OSAG78 exhibited altered phenotypes, including smaller leaves and rounder flowers, and also demonstrated a late flowering phenotype that could be rescued by gibberellin A(3) (GA(3)) application. Several flowering-related genes were analyzed, indicating that the expression of gibberellin-stimulated genes was decreased in the plants overexpressing OSAG78. Also, the expression of AtGA2ox1, AtGA3ox1 and AtGA20ox1 genes encoding GA2-, GA3- and GA20-oxidases, respectively, which are mainly responsible for gibberellin metabolism, was decreased, and the level of GA(4), a bioactive gibberellin, measured by gas chromatography-mass spectrometry was also reduced in the overexpressing lines. Furthermore, the expression levels of AtGA3ox1 and AtGA20ox1 were significantly decreased in wild-type Arabidopsis treated with linoleic acid, linolenic acid or methyl jasmonate. The membrane-bound OSAG78 might hydrolyze phospholipids to release linoleic acid and linolenic acid, and then depress the expression of genes encoding GA3- and GA20-oxidase. These changes reduced the bioactive gibberellin level, and, finally, late flowering occurred. Our results indicate that a patatin-like membrane protein with lipase activity affects flowering through the regulation of gibberellin metabolism.     

Genome‐based estimates of fungal rDNA copy number variation across phylogenetic scales and ecological lifestyles

Ribosomal DNA (rDNA) copy number variation (CNV) has major physiological implications for all organisms, but how it varies for fungi, an ecologically ubiquitous and important group of microorganisms, has yet to be systemically investigated. Here, we examine rDNA CNV using an in silico read depth approach for 91 fungal taxa with sequenced genomes and assess copy number conservation across phylogenetic scales and ecological lifestyles. rDNA copy number varied considerably across fungi, ranging from an estimated 14 to 1,442 copies (mean = 113, median = 82), and copy number similarity was inversely correlated with phylogenetic distance. No correlations were found between rDNA CNV and fungal trophic mode, ecological guild or genome size. Taken together, these results show that like other microorganisms, fungi exhibit substantial variation in rDNA copy number, which is linked to their phylogeny in a scale‐dependent manner.