大鼠出生后脑内钙调神经磷酸酶的研究

本文用BA-ELISA.immunoblotting及酶活力测定等方法,研究了大鼠脑中钙调神经磷酸酶在大鼠出生后的变化情况。结果表明,钙调神经磷酸酶的含量在大鼠出生后第二周和第三周显著增加,其活力也在出生后第二周达到顶峰。钙调神经磷酸酶这种有规律的变化与脑中突触形成在时间上是一致的,暗示钙调神经磷酸酶可能参与突触功能的调节。     

Litter and soil biodiversity jointly drive ecosystem functions

The decomposition of litter and the supply of nutrients into and from the soil are two fundamental processes through which the above- and belowground world interact. Microbial biodiversity, and especially that of decomposers, plays a key role in these processes by helping litter decomposition. Yet the relative contribution of litter diversity and soil biodiversity in supporting multiple ecosystem services remains virtually unknown. Here we conducted a mesocosm experiment where leaf litter and soil biodiversity were manipulated to investigate their influence on plant productivity, litter decomposition, soil respiration, and enzymatic activity in the littersphere. We showed that both leaf litter diversity and soil microbial diversity (richness and community composition) independently contributed to explain multiple ecosystem functions. Fungal saprobes community composition was especially important for supporting ecosystem multifunctionality (EMF), plant production, litter decomposition, and activity of soil phosphatase when compared with bacteria or other fungal functional groups and litter species richness. Moreover, leaf litter diversity and soil microbial diversity exerted previously undescribed and significantly interactive effects on EMF and multiple individual ecosystem functions, such as litter decomposition and plant production. Together, our work provides experimental evidence supporting the independent and interactive roles of litter and belowground soil biodiversity to maintain ecosystem functions and multiple services.     

Nitrogen addition promotes terrestrial plants to allocate more biomass to aboveground organs: A global meta-analysis

A significant increase in reactive nitrogen (N) added to terrestrial ecosystems through agricultural fertilization or atmospheric deposition is considered to be one of the most widespread drivers of global change. Modifying biomass allocation is one primary strategy for maximizing plant growth rate, survival, and adaptability to various biotic and abiotic stresses. However, there is much uncertainty as to whether and how plant biomass allocation strategies change in response to increased N inputs in terrestrial ecosystems. Here, we synthesized 3516 paired observations of plant biomass and their components related to N additions across terrestrial ecosystems worldwide. Our meta-analysis reveals that N addition (ranging from 1.08 to 113.81 g m⁻² year⁻¹) increased terrestrial plant biomass by 55.6% on average. N addition has increased plant stem mass fraction, shoot mass fraction, and leaf mass fraction by 13.8%, 12.9%, and 13.4%, respectively, but with an associated decrease in plant reproductive mass (including flower and fruit biomass) fraction by 3.4%. We further documented a reduction in plant root-shoot ratio and root mass fraction by 27% (21.8%–32.1%) and 14.7% (11.6%–17.8%), respectively, in response to N addition. Meta-regression results showed that N addition effects on plant biomass were positively correlated with mean annual temperature, soil available phosphorus, soil total potassium, specific leaf area, and leaf area per plant. Nevertheless, they were negatively correlated with soil total N, leaf carbon/N ratio, leaf carbon and N content per leaf area, as well as the amount and duration of N addition. In summary, our meta-analysis suggests that N addition may alter terrestrial plant biomass allocation strategies, leading to more biomass being allocated to aboveground organs than belowground organs and growth versus reproductive trade-offs. At the global scale, leaf functional traits may dictate how plant species change their biomass allocation pattern in response to N addition.     

Microbial nitrogen and phosphorus co-limitation across permafrost region

The status of plant and microbial nutrient limitation have profound impacts on ecosystem carbon cycle in permafrost areas, which store large amounts of carbon and experience pronounced climatic warming. Despite the long-term standing paradigm assumes that cold ecosystems primarily have nitrogen deficiency, large-scale empirical tests of microbial nutrient limitation are lacking. Here we assessed the potential microbial nutrient limitation across the Tibetan alpine permafrost region, using the combination of enzymatic and elemental stoichiometry, genes abundance and fertilization method. In contrast with the traditional view, the four independent approaches congruently detected widespread microbial nitrogen and phosphorus co-limitation in both the surface soil and deep permafrost deposits, with stronger limitation in the topsoil. Further analysis revealed that soil resources stoichiometry and microbial community composition were the two best predictors of the magnitude of microbial nutrient limitation. High ratio of available soil carbon to nutrient and low fungal/bacterial ratio corresponded to strong microbial nutrient limitation. These findings suggest that warming-induced enhancement in soil nutrient availability could stimulate microbial activity, and probably amplify soil carbon losses from permafrost areas.     

几种猕猴桃种间杂交亲和性的探讨

以中华猕猴桃、毛花猕猴桃、美味猕猴桃及阔叶猕猴桃进行种间杂交,结果表明:各杂交组合的座果率与对照组一样,均为100％;父本花粉萌发率与对照组相近,其杂交当代果实重量、种子数量及种子千粒重也与对照组相近;相同的母本,其当代杂交果实的重量及种子数量与父本花粉萌发率的高低成正比。这不但说明了各杂交组合所采用亲本之间的亲和性,而且为生产上利用不同种生活力强的猕猴桃雄株花粉进行人工辅助授粉提供依据。     

Climate–ecosystem modelling made easy: The Land Sites Platform

Dynamic Global Vegetation Models (DGVMs) provide a state-of-the-art process-based approach to study the complex interplay between vegetation and its physical environment. For example, they help to predict how terrestrial plants interact with climate, soils, disturbance and competition for resources. We argue that there is untapped potential for the use of DGVMs in ecological and ecophysiological research. One fundamental barrier to realize this potential is that many researchers with relevant expertize (ecology, plant physiology, soil science, etc.) lack access to the technical resources or awareness of the research potential of DGVMs. Here we present the Land Sites Platform (LSP): new software that facilitates single-site simulations with the Functionally Assembled Terrestrial Ecosystem Simulator, an advanced DGVM coupled with the Community Land Model. The LSP includes a Graphical User Interface and an Application Programming Interface, which improve the user experience and lower the technical thresholds for installing these model architectures and setting up model experiments. The software is distributed via version-controlled containers; researchers and students can run simulations directly on their personal computers or servers, with relatively low hardware requirements, and on different operating systems. Version 1.0 of the LSP supports site-level simulations. We provide input data for 20 established geo-ecological observation sites in Norway and workflows to add generic sites from public global datasets. The LSP makes standard model experiments with default data easily achievable (e.g., for educational or introductory purposes) while retaining flexibility for more advanced scientific uses. We further provide tools to visualize the model input and output, including simple examples to relate predictions to local observations. The LSP improves access to land surface and DGVM modelling as a building block of community cyberinfrastructure that may inspire new avenues for mechanistic ecosystem research across disciplines.     

Long-term changes in Noctiluca scintillans blooms along the Chinese coast from 1933 to 2020

Noctiluca scintillans is one of the most common harmful algal species and widely known due to its bioluminescence. In this study, the spatial distribution, seasonal variations, and long-term trends of N. scintillans blooms in China and the related drivers were analyzed and discussed. From 1933 to 2020, a total of 265 events of N. scintillans blooms were recorded in Chinese coastal waters, with a total duration of 1052 days. The first N. scintillans bloom occurred in Zhejiang in 1933, and only three events were recorded before 1980. From 1981 to 2020, N. scintillans caused harmful algal blooms (HABs) almost every year, both the average duration and the proportion of multiphase HABs showed an increasing trend. 1986–1992, 2002–2004, and 2009–2016 were the three peak periods with a frequency of no less than five events of N. scintillans blooms per year. In terms of spatial distribution, N. scintillans blooms spread from the Southeast China Sea to the Bohai Sea after 2000, Guangdong, Fujian, and Hebei were the three provinces with the highest numbers of recorded events of N. scintillans blooms. Moreover, 86.8% of the events of N. scintillans blooms occurred in spring (March, April, and May) and summer (June, July, and August). Among environmental factors, the dissolved inorganic phosphate, dissolved silicate and chemical oxygen demand were significantly correlated with the cell density of N. scintillans during N. scintillans blooms, and most of N. scintillans blooms were recorded in the temperature range of 18.0–25.0°C. Precipitation, hydrodynamics, water temperature, and food availability might be the main factors affecting the spatial–temporal distribution of N. scintillans blooms along the Chinese coast.     

Carbon Sink-to-Source Transition Is Coordinated with Establishment of Cell-Specific Gene Expression in a C4 Plant

Plants that use the highly efficient C4 photosynthetic pathway possess two types of specialized leaf cells, the mesophyll and bundle sheath. In mature C4 leaves, the CO2 fixation enzyme ribulose-1,5-bisphosphate carboxylase (RuBPCase) is specifically compartmentalized to the bundle sheath cells. However, in very young leaves of amaranth, a dicotyledonous C4 plant, genes encoding the large subunit and small subunit of RuBPCase are initially expressed in both photosynthetic cell types. We show here that the RuBPCase mRNAs and proteins become specifically localized to leaf bundle sheath cells during the developmental transition of the leaf from carbon sink to carbon source. Bundle sheath cell-specific expression of RuBPCase genes and the sink-to-source transition began initially at the leaf apex and progressed rapidly and coordinately toward the leaf base. These findings demonstrated that two developmental transitions, the change in photoassimilate transport status and the establishment of bundle sheath cell-specific RuBPCase gene expression, are tightly coordinated during C4 leaf development. This correlation suggests that processes associated with the accumulation and transport of photosynthetic compounds may influence patterns of photosynthetic gene expression in C4 plants.     

孕产妇生殖道单纯疱疹病毒感染垂直污染羊水的研究

用ＤＮＡ聚合酶链反应检测单纯疱疹病毒特异性核酸,调查１００名孕产妇生殖器官脂ＨＳＶ感染和羊水受ＨＳＶ污染的情况,结果表明：受感染的母体通过病毒护散途径及通过产道途径,污染羊水的机率分别为１１．１％和５４．５％;原发性ＨＳＶ、继发性ＨＳＶ垂直污染羊水机率分别为６６．７％和２９．４％;不同妊娠期和生育胎次对污染率无显著性影响。     

国产7种乌头属植物的核型研究

本文报道了国产7种乌头属植物（两色乌头（Aconitum alboviolaceum Kom.,牛扁 A.barbartum var.puberulum Ledeb.,蔓乌头A.volubile Pall.,展毛蔓乌头 A.ciliare DC.,北乌头 A.kusnezoffii Reichb.,蒿叶乌头 A.artemisiaefolium Bar.et Skv.,细叶乌头 A.macrorhgnchum Turcz.）的核型。其中展毛蔓乌头、蒿叶乌头和细叶乌头的核型为首次报道。本文还首次指出乌头属中具多年生根状茎的牛扁亚属植物的核型没有明显的二型性,而具二年生块根的乌头正属植物的核型的二型性十分明显。此外还讨论了细叶乌头及展毛蔓乌头的系统位置,认为它们与蔓乌头有较近的亲缘关系。