scholarly journals Developmental characteristics of sporogenous hyphae: a new observation between Brassica juncea var. tumida and Albugo candida

2021 ◽  
Author(s):  
Zilan Xiao ◽  
Ning Gong ◽  
Xiaojun Zhou ◽  
Liyan Zhu ◽  
Xiaochan He ◽  
...  
Keyword(s):  
Brassica Juncea ◽  
Developmental Process ◽  
Outer Wall ◽  
Raw Material ◽  
Economic Losses ◽  
Ultrastructural Observation ◽  
Negative Effects ◽  
Albugo Candida ◽  
White Blister ◽  
Developmental Characteristics

AbstractBrassica juncea var. tumida (tumorous stem mustard) is widely cultivated as a feature vegetable in Ningbo, Zhejiang Province, and is used as a raw material for pickles in China. White blister rust, caused by Albugo candida, has severe negative effects on tumorous stem mustard, resulting in significant economic losses. In this study, hypha colonization and extension, haustorial formation, and the development process of sporogenous hyphae and sporangia in A. candida-infected tissues were studied using light and transmission electron microscopy. Additionally, the complex and unique sporogenous hypha developmental process was revealed. During A. candida infection, cytological and ultrastructural characteristics were similar to those of cruciferous plants. During sporogenous hyphae development, an initially cylindrical sporogenous hypha with a thin inner wall at the apex developed from a cell with a thick inner wall. At the apical end of the sporogenous hypha, an electron-dense complex gathered, causing the disintegration of the inner and outer walls and the formation of new inner and outer walls. With the formation of a clavate sporogenous hypha, a deep constriction of the cell wall occurred at its subapex, in which a septum was produced and a primary sporangium was separated from the sporogenous hypha. Both layers of the sporogenous hypha wall took part in the formation of the sporangial wall but were not related the formation of the sporangial outer wall in a septum, providing direct evidence of the holoblastic formation of sporangia. Furthermore, ultrastructural observation demonstrated that the development of the primary sporangial walls within a septum occurred later than that of their lateral walls, including the degradation of constricted outer walls around the septum, formation of the inner wall and subsequent outer walls of a sporangium in the upper septum layers, confirming the earlier observation. Therefore, this study provided the model of sporogenous hyphae development and sporangial formation in chain.

scholarly journals First confirmed report of white blister rust disease caused by Albugo candida on Isatis emarginata

2018 ◽  
Vol 100 (3) ◽  
pp. 587-587
Author(s):  
Mohammad Reza Mirzaee ◽  
Sebastian Ploch ◽  
Lisa Nigrelli ◽  
Sepide Sajedi ◽  
Marco Thines
Keyword(s):  
Rust Disease ◽  
Albugo Candida ◽  
Blister Rust ◽  
White Blister ◽  
White Blister Rust

scholarly journals The Management Response to Wind Disturbances in European Forests

2021 ◽  
Author(s):  
Paula Sanginés de Cárcer ◽  
Piotr S. Mederski ◽  
Natascia Magagnotti ◽  
Raffaele Spinelli ◽  
Benjamin Engler ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Economic Losses ◽  
Future Research ◽  
Forest Site ◽  
Negative Effects ◽  
Salvage Logging ◽  
Forest Ownership ◽  
Forest Ecosystem Services ◽  
Disturbance Management ◽  
Timber Market

Abstract Purpose of the Review The review synthesises the current knowledge of post-windstorm management in selected European countries in order to identify knowledge gaps and guide future research. Recent Findings Despite the differences in forest ownership and national regulations, management experiences in Europe converge at (1) the need for mechanization of post-windthrow management to ensure operator safety, (2) the importance to promote operator training and optimise the coordination between all the actors involved in disturbance management and (3) the need to implement measures to consolidate the timber market while restoring forest ecosystem services and maintain biodiversity. Summary Windstorms are natural disturbances that drive forest dynamics but also result in socio-economic losses. As the frequency and magnitude of wind disturbances will likely increase in the future, improved disturbance management is needed. We here highlight the best practices and remaining challenges regarding the strategic, operational, economic and environmental dimensions of post-windthrow management in Europe. Our literature review underlined that post-disturbance management needs to be tailored to each individual situation, taking into account the type of forest, site conditions, available resources and respective legislations. The perspectives on windthrown timber differ throughout Europe, ranging from leaving trees on site to storing them in sophisticated wet storage facilities. Salvage logging is considered important in forests susceptible to bark beetle outbreaks, while no salvage logging is recommended in forests protecting against natural hazards. Remaining research gaps include questions of balancing between the positive and negative effects of salvage logging and integrating climate change considerations more explicitly in post-windthrow management.

scholarly journals On certain issues related to chronic exposure to occupational noise and impacts exerted by it on workers’ bodies (literature review)

2021 ◽  
pp. 186-196
Author(s):  
V.F. Spirin ◽  
◽  
A.M. Starshov ◽  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Chronic Exposure ◽  
Life Quality ◽  
Research Literature ◽  
Sensorineural Hearing ◽  
Economic Losses ◽  
Physical Factors ◽  
Negative Effects ◽  
Work Related

Chronic exposure to noise becomes especially significant when it occurs at workplaces since it results not only in deteriorated life quality of workers but also in disorders in their occupational activities. Occupational sensorineural hearing loss (SHL) holds the 1st rank place among occupational diseases caused by exposure to industrial physical factors. As any other work-related disease, sensorineural hearing loss makes it more difficult to preserve labor resources in the country and leads to significant economic losses. Given that, it is extremely vital to develop procedures for early diagnostics, to determine all possible risks that cause hearing loss directly or indirectly, and to create efficient prevention activities aimed at preserving health of workers exposed to noise at their workplaces. We reviewed literature data published over the last 5–7 years and analyzed more than 100 scientific works on the matter. Our review covers data from 61 sources that are the most relevant regarding tasks we aimed to solve in this research. Literature analysis allowed us to conclude that hearing loss caused by chronic exposure to noise at a workplace was a rather significant problem outlined by occupational medicine experts all over the world. It was shown that noise factor, apart from its direct impacts on the acoustic apparatus, produced apparent negative effects on many organs and systems causing various functional disorders in them which could directly or indirectly exacerbate hearing loss in workers.

scholarly journals Scientistsʼ Warning on Climate Change and Medicinal Plants

Planta Medica ◽  
2019 ◽  
Vol 86 (01) ◽  
pp. 10-18 ◽  
Author(s):  
Wendy L. Applequist ◽  
Josef A. Brinckmann ◽  
Anthony B. Cunningham ◽  
Robbie E. Hart ◽  
Michael Heinrich ◽  
...  
Keyword(s):  
Climate Change ◽  
Medicinal Plants ◽  
Raw Material ◽  
Negative Effects ◽  
Medicinal Species ◽  
Temperature And Precipitation ◽  
Anthropogenic Habitat ◽  
Precipitation Regimes ◽  
Chemical Content ◽  
Mitigate Climate Change

AbstractThe recent publication of a World Scientistsʼ Warning to Humanity highlighted the fact that climate change, absent strenuous mitigation or adaptation efforts, will have profound negative effects for humanity and other species, affecting numerous aspects of life. In this paper, we call attention to one of these aspects, the effects of climate change on medicinal plants. These plants provide many benefits for human health, particularly in communities where Western medicine is unavailable. As for other species, their populations may be threatened by changing temperature and precipitation regimes, disruption of commensal relationships, and increases in pests and pathogens, combined with anthropogenic habitat fragmentation that impedes migration. Additionally, medicinal species are often harvested unsustainably, and this combination of pressures may push many populations to extinction. A second issue is that some species may respond to increased environmental stresses not only with declines in biomass production but with changes in chemical content, potentially affecting quality or even safety of medicinal products. We therefore recommend actions including conservation and local cultivation of valued plants, sustainability training for harvesters and certification of commercial material, preservation of traditional knowledge, and programs to monitor raw material quality in addition to, of course, efforts to mitigate climate change.

Expression and relationships of resistance to white rust (Albugo candida) at cotyledonary, seedling, and flowering stages in Brassica juncea germplasm from Australia, China, and India

2007 ◽  
Vol 58 (3) ◽  
pp. 259 ◽  
Author(s):  
C. X. Li ◽  
K. Sivasithamparam ◽  
G. Walton ◽  
P. Salisbury ◽  
W. Burton ◽  
...  
Keyword(s):  
Plant Growth ◽  
Brassica Juncea ◽  
Environmental Conditions ◽  
Host Resistance ◽  
Growth Stages ◽  
Sources Of Resistance ◽  
Albugo Candida ◽  
White Rust ◽  
China And India ◽  
Canola Quality

White rust (Albugo candida) is a highly destructive disease of oilseed Brassicas such as Brassica juncea and B. rapa. Most commercial B. juncea or B. rapa varieties are highly susceptible and yield losses from combined infection of leaves and inflorescences can be up to 20% or 60% in Australia and India, respectively. In Australia, canola-quality B. juncea has been developed to extend oilseed Brassica production into lower rainfall areas, with the first commercial B. juncea canola-quality variety planned for release in 2006. It is essential to identify useful sources of host resistance in B. juncea as breeding and/or selection of material for resistance is the most cost-effective method of delivering control for farmers. Three experiments were undertaken under controlled-environmental conditions to identify the best methods of characterising host resistance and to identify sources of resistance in B. juncea germplasm from Australia, China, and India. Forty-four B. juncea genotypes, viz. 22 from India, 12 from Australia, and 10 from China, were tested. Four Chinese genotypes (CBJ-001, CBJ-002, CBJ-003, CBJ-004) and one Australian genotype (JR049) consistently showed high resistance to A. candida across the different plant growth stages against a pathotype prevailing in Australia. Similarly, the most susceptible genotypes (viz. Indian genotypes RH781, RL1359, RH819) were extremely susceptible irrespective of the plant growth stage. Overall, although disease severity on cotyledons and leaves at the different growth stages was significantly and positively correlated, there was, however, no significant correlation between the number of stagheads and any of the other disease parameters measured. Our study demonstrates that controlled-environmental conditions are suitable for rapid identification of resistant genotypes and that genotypes with high levels of resistance can be reliably identified at the cotyledonary, seedling, or flowering stages.

scholarly journals The defensive benefit and flower number cost of selenium accumulation in Brassica juncea

AoB Plants ◽  
2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Janet C Steven ◽  
Alexander Culver
Keyword(s):  
Brassica Juncea ◽  
Pieris Rapae ◽  
Leaf Tissue ◽  
Plant Size ◽  
Sodium Selenate ◽  
Negative Effects ◽  
Flower Number ◽  
Specialist Herbivore ◽  
Selenium Accumulation ◽  
The Cost

Abstract Some plant species accumulate selenium in their tissues in quantities far above soil concentrations, and experiments demonstrate that selenium can serve as a defence against herbivores and pathogens. However, selenium may also cause oxidative stress and reduce growth in plants. We measured growth, selenium accumulation and herbivory in four varieties of the selenium accumulator Brassica juncea to investigate the cost of accumulation as well as its benefit in reducing herbivory. We measured selenium levels, plant size and flower number in four varieties of B. juncea watered with sodium selenate or treated as controls. We also conducted no-choice herbivory trials on leaves from both treatments with the specialist herbivore Pieris rapae. The selenate treatment slightly increased leaf number over the control, but tissue concentrations of selenium and flower number were negatively correlated in some varieties. In herbivory trials, leaves from the plants in the selenate treatment lost less leaf tissue, and the majority of larvae given leaves from selenate-treated plants ate very little leaf tissue at all. In the variety with the highest selenium accumulation, leaves from selenate-treated plants that showed reduced flower production also experienced less herbivory in feeding trials. The protective advantage of greater selenium accumulation may be offset by negative effects on reproduction, and the relatively low level of selenium accumulation in this species as compared to more extreme hyperaccumulators could reflect the minimum level necessary to enhance protection from herbivory.

scholarly journals Staphylococcus aureus Exotoxins and Their Detection in the Dairy Industry and Mastitis

Toxins ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 537 ◽  
Author(s):  
Ana G. Abril ◽  
Tomás G. Villa ◽  
Jorge Barros-Velázquez ◽  
Benito Cañas ◽  
Angeles Sánchez-Pérez ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Industry ◽  
Food Poisoning ◽  
Microbial Colonization ◽  
Economic Losses ◽  
Human Consumption ◽  
Negative Effects ◽  
Virulence Proteins ◽  
Causative Agents ◽  
Best Medical Therapy

Staphylococcus aureus constitutes a major food-borne pathogen, as well as one of the main causative agents of mastitis in dairy ruminants. This pathogen can produce a variety of extracellular toxins; these include the shock syndrome toxin 1 (TSST-1), exfoliative toxins, staphylococcal enterotoxins (SE), hemolysins, and leukocidins. S. aureus expresses many virulence proteins, involved in evading the host defenses, hence facilitating microbial colonization of the mammary glands of the animals. In addition, S. aureus exotoxins play a role in the development of both skin infections and mastitis. Indeed, if these toxins remain in dairy products for human consumption, they can cause staphylococcal food poisoning (SFP) outbreaks. As a result, there is a need for procedures to identify the presence of exotoxins in human food, and the methods used must be fast, sensitive, reliable, and accurate. It is also essential to determine the best medical therapy for human patients suffering from S. aureus infections, as well as establishing the relevant veterinary treatment for infected ruminants, to avoid economic losses in the dairy industry. This review summarizes the role of S. aureus toxins in the development of mastitis in ruminants, their negative effects in the food and dairy industries, and the different methods used for the identification of these toxins in food destined for human consumption.

Pustula junggarensis (Albuginales, Oomycota), a new species of white blister rust on Takhtajaniantha pusilla from Junggar Basin in China

Phytotaxa ◽  
2016 ◽  
Vol 289 (1) ◽  
pp. 83 ◽  
Author(s):  
BIAO XU ◽  
JIAGE GE SONG ◽  
PING GEN XI ◽  
ZI DE JIANG
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Junggar Basin ◽  
Outer Wall ◽  
Mtdna Sequences ◽  
Blister Rust ◽  
White Blister ◽  
White Blister Rust ◽  
Distinct Lineage ◽  
A New Species

An unknown white blister rust was collected on Takhtajaniantha pusilla (Pall.) Nazarovain (Asteraceae) in the desert regions of Junggar Basin in China. The pathogen is characterized by depressed primary sporangia,subglobose secondary sporangia with annulus, yellowish to dark reddish-brown oospores, (45.4)54.6–65.4(68.5) µm in diameter, with inner walls on average up to 2.7 µm thick and outer wall on average up to 5.2 µm thick, which is obviously larger than in the morphologically similar P. obtusata and P. helianthicola. Phylogenetic analyses based on cox2 mtDNA sequences provided the evidence that this pathogen is separated from other species of Pustula and forms a distinct lineage. Therefore, we consider this pathogen as a new species of Pustula, described here as Pustula junggarensis.

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