eMedicine创建于1996年，由近万名临床医师作为作者或编辑参与此临床医学知识库的建设，其中编辑均是来自美国哈佛、耶鲁、斯坦福、芝加哥、德克萨斯、加州大学等各分校医学院的教授或副教授。

eMedicine

Currently, food security depends on the increased production of cereals such as wheat (Triticum aestivum L.), which is an important source of calories and protein for humans. However, cells of the crop have suffered from the accumulation of reactive oxygen species (ROS), which can cause severe oxidative damage to the plants, due to environmental stresses. ROS are toxic molecules found in various subcellular compartments. The equilibrium between the production and detoxification of ROS is sustained by enzymatic and nonenzymatic antioxidants. In the present review, we offer a brief summary of antioxidant defense and hydrogen peroxide (H2O2) signaling in wheat plants. Wheat plants increase antioxidant defense mechanisms under abiotic stresses, such as drought, cold, heat, salinity and UV-B radiation, to alleviate oxidative damage. Moreover, H2O2 signaling is an important factor contributing to stress tolerance in cereals.

/pdf/antioxidant-responses-of-wheat-plants-under-stress-2293932w9r.pdf

Antioxidant responses of wheat plants under stress

This chapter discusses a current comparator. The design of the various components of a comparator may be affected by these factors. To detect short circuit and insulation faults arising during construction and to confirm the effectiveness of the shielding as it is installed, the probe test should be carried out at frequent intervals during the construction.

Design and construction

It is well known that plant photosynthesis and respiration are two fundamental and crucial physiological processes, while the critical role of the antioxidant system in response to abiotic factors is still a focus point for investigating physiological stress. Although one key metabolic process and its response to climatic change have already been reported and reviewed, an integrative review, including several biological processes at multiple scales, has not been well reported. The current review will present a synthesis focusing on the underlying mechanisms in the responses to elevated CO2 at multiple scales, including molecular, cellular, biochemical, physiological, and individual aspects, particularly, for these biological processes under elevated CO2 with other key abiotic stresses, such as heat, drought, and ozone pollution, as well as nitrogen limitation. The present comprehensive review may add timely and substantial information about the topic in recent studies, while it presents what has been well established in previous reviews. First, an outline of the critical biological processes, and an overview of their roles in environmental regulation, is presented. Second, the research advances with regard to the individual subtopics are reviewed, including the response and adaptation of the photosynthetic capacity, respiration, and antioxidant system to CO2 enrichment alone, and its combination with other climatic change factors. Finally, the potential applications for plant responses at various levels to climate change are discussed. The above issue is currently of crucial concern worldwide, and this review may help in a better understanding of how plants deal with elevated CO2 using other mainstream abiotic factors, including molecular, cellular, biochemical, physiological, and whole individual processes, and the better management of the ecological environment, climate change, and sustainable development.

/pdf/response-and-adaptation-of-photosynthesis-respiration-and-4oy6965xot.pdf

Response and adaptation of photosynthesis, respiration, and antioxidant systems to elevated CO2 with environmental stress in plants.

The time when plant biostimulants were considered as "snake oil" is erstwhile and the skepticism regarding their agricultural benefits has significantly faded, as solid scientific evidences of their positive effects are continuously provided. Currently plant biostimulants are considered as a full-fledged class of agri-inputs and highly attractive business opportunity for major actors of the agroindustry. As the dominant category of the biostimulant segment, seaweed extracts were key in this growing renown. They are widely known as substances with the function of mitigating abiotic stress and enhancing plant productivity. Seaweed extracts are derived from the extraction of several macroalgae species, which depending on the extraction methodology lead to the production of complex mixtures of biologically active compounds. Consequently, plant responses are often inconsistent, and precisely deciphering the involved mechanism of action remains highly intricate. Recently, scientists all over the world have been interested to exploring hidden mechanism of action of these resources through the employment of multidisciplinary and high-throughput approaches, combining plant physiology, molecular biology, agronomy, and multi-omics techniques. The aim of this review is to provide fresh insights into the concept of seaweed extract (SE), through addressing the subject in newfangled standpoints based on current scientific knowledge, and taking into consideration both academic and industrial claims in concomitance with market's requirements. The crucial extraction process as well as the effect of such products on nutrient uptake and their role in abiotic and biotic stress tolerance are scrutinized with emphasizing the involved mechanisms at the metabolic and genetic level. Additionally, some often overlooked and indirect effects of seaweed extracts, such as their influence on plant microbiome are discussed. Finally, the plausible impact of the recently approved plant biostimulant regulation on seaweed extract industry is addressed.

Trends in Seaweed Extract Based Biostimulants: Manufacturing Process and Beneficial Effect on Soil-Plant Systems

The problem of climate change is unavoidably accompanied by climate variabilities, such as high temperature, varying patterns of rainfall, and other environmental factors (including biotic factors), and causes an adverse impact on plant development and global food security [...]

https://www.mdpi.com/2073-4433/12/4/451/pdf

Plant Adaptation to Global Climate Change

Cerebral hydatid cyst is a rare entity seen in upto 2%.[1] It can be primary (single) or secondary (multiple). 18 year old male presented with chief complaints of headache, nausea, vomiting. Non Contrast Computed Tomography (NCCT) and Contrast Enhanced Magnetic Resonance Imaging (CEMRI) findings revealed possibility of hydatid cyst. Surgery remains mainstay of treatment. The patient was operated and pathology report confirmed the diagnosis.

/pdf/a-rare-case-of-large-solitary-cerebral-hydatid-cyst-k6acgx5t64.pdf

A rare case of large solitary cerebral hydatid cyst

The U-Box E3 ubiquitin ligase, AtPUB46, functions in the drought response: T-DNA insertion mutants of this single paralogous gene are hypersensitive to water- and oxidative stress (Adler et al. BMC Plant Biology 17:8, 2017). Here we analyze the phenotype of AtPUB46 overexpressing (OE) plants. AtPUB46-OE show increased tolerance to water stress and have smaller leaf blades and reduced stomatal pore size and stomatal index compared with wild type (WT). Despite this, the rate of water loss from detached rosettes is similar in AtPUB46-OE and WT plants. Germination of AtPUB46-OE seeds was less sensitive to salt than WT whereas seedling greening was more sensitive. We observed a complex response to oxidative stress applied by different agents: AtPUB46-OE plants were hypersensitive to H2O2 but hyposensitive to methyl viologen. AtPUB46-GFP fusion protein is cytoplasmic, however, in response to H2O2 a considerable proportion translocates to the nucleus. We conclude that the differential stress phenotype of the AtPUB46-OE does not result from its smaller leaf size or reduced stomata but from changes in the activity of a stress pathway regulated by a degradation substrate of the AtPUB46 E3.

https://www.biorxiv.org/content/biorxiv/early/2018/07/30/379859.full.pdf

Amit Kumar Mishra

Papers

Plant Adaptation to Global Climate Change

A rare case of large solitary cerebral hydatid cyst

Overexpression of Arabidopsis ubiquitin ligase AtPUB46 enhances tolerance to drought and oxidative stress