Assessing the role of plant trade networks in the vulnerability of forest nurseries to plant pathogens

2021 ◽  
Author(s):  
Madeline Marshall ◽  
Roanne Sutherland ◽  
Philip E. Hulme
Keyword(s):  
Plant Pathogens ◽  
Trade Networks ◽  
Forest Nurseries

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

scholarly journals The role of exochitinase type A1 in the fungistatic activity of the rhizosphere bacterium Paenibacillus sp. M4

2016 ◽  
Vol 68 (2) ◽  
pp. 451-459
Author(s):  
Urszula Jankiewicz ◽  
Maria Swiontek-Brzezinska
Keyword(s):  
Plant Pathogens ◽  
Chitinase Activity ◽  
Maximum Activity ◽  
Synergistic Action ◽  
Chitinolytic Activity ◽  
Fungistatic Activity ◽  
Rhizosphere Bacterium ◽  
Paenibacillus Sp ◽  
Growth Inhibiting

The aim of the study was to detect the activity and characterize potentially fungistatic chitinases synthesized by rhizosphere bacteria identified as Paenibacillus sp. M4. Maximum chitinolytic activity was achieved on the fifth day of culturing bacteria in a growth medium with 1% colloidal chitin. Analysis of a zymogram uncovered the presence of four activity bands in the crude bacterial extract. The used three-stage protein purification procedure resulted in a single band of chitinase activity on the zymogram. The purified enzyme exhibited maximum activity at pH 6.5 and temperature 45oC, and thermal stability at 40oC for 4 h. In terms of substrate specificity, it is an exochitinase (chitobiose). The amino acid sequence obtained after mass spectrometry showed similarity to chitinase A1 synthesized by Bacillus circulans. The M4 isolate demonstrated the highest growth inhibiting activity against plant pathogens belonging to the genera Fusarium, Rhizoctonia and Alternaria. Fungistatic activity, although to a somewhat lesser degree, was also demonstrated by purified chitinase. The obtained results confirm the participation of the studied exochitinase in antagonism towards pathogenic molds. However, the lower fungistatic effectiveness of the chitinases points to the synergistic action of different metabolites in biocontrol by these bacteria.

Bartering for Slaves on the Upper Guinea Coast in the Early Seventeenth Century

2012 ◽  
Author(s):  
LINDA A. NEWSON
Keyword(s):  
Seventeenth Century ◽  
Slave Trade ◽  
17Th Century ◽  
Detailed Account ◽  
Guinea Coast ◽  
Trade Networks ◽  
Slave Traders ◽  
Atlantic Slave Trade ◽  
Trading Network

In the context of debates about the definition and origins of globalisation and the role of African agency in the Atlantic slave trade, this chapter examines the commodities traded by Portuguese New Christian slave traders on the Upper Guinea coast in the early 17th century. Based on detailed account books of three slave traders discovered in the Inquisition section of the Archivo General de la Nación in Lima, Peru, it shows how Africans often determined the types and prices of goods exchanged and forced Europeans to adapt to local trade networks. Hence while commodities such as Indian textiles and beads reflected the position of the Portuguese slave traders in a global trading network, at the same time they were actively involved in trading locally produced cloth and beeswax as well as slaves.

scholarly journals Fungi and Oomycetes in the Irrigation Water of Forest Nurseries

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 459 ◽  
Author(s):  
Adas Marčiulynas ◽  
Diana Marčiulynienė ◽  
Jūratė Lynikienė ◽  
Artūras Gedminas ◽  
Miglė Vaičiukynė ◽  
...  
Keyword(s):  
Irrigation Water ◽  
Plant Pathogens ◽  
High Throughput Sequencing ◽  
Irrigation System ◽  
Tree Seedlings ◽  
High Quality ◽  
Forest Nurseries ◽  
Study Sites ◽  
Microbial Samples

The aim of the present study was to assess fungal and oomycete communities in the irrigation water of forest nurseries, focusing on plant pathogens in the hope of getting a better understanding of potential pathogenic microorganisms and spreading routes in forest nurseries. The study sites were at Anykščiai, Dubrava, Kretinga and Trakai state forest nurseries in Lithuania. For the collection of microbial samples, at each nursery five 100-L water samples were collected from the irrigation ponds and filtered. Following DNA isolation from the irrigation water filtrate samples, these were individually amplified using ITS rDNA as a marker and subjected to PacBio high-throughput sequencing. Clustering in the SCATA pipeline and the taxonomic classification of 24,006 high-quality reads showed the presence of 1286 non-singleton taxa. Among those, 895 were representing fungi and oomycetes. The detected fungi were 57.3% Ascomycota, 38.1% Basidiomycota, 3.1% Chytridiomycota, 0.8% Mucoromycota and 0.7% Oomycota. The most common fungi were Malassezia restricta E. Guého, J. Guillot & Midgley (20.1% of all high-quality fungal sequences), Pezizella discreta (P. Karst.) Dennis (10.8%) and Epicoccum nigrum Link (4.9%). The most common oomycetes were Phytopythium cf. citrinum (B. Paul) Abad, de Cock, Bala, Robideau, Lodhi & Lévesque (0.4%), Phytophthora gallica T. Jung & J. Nechwatal (0.05%) and Peronospora sp. 4248_322 (0.05%). The results demonstrated that the irrigation water used by forest nurseries was inhabited by a species-rich but largely site-specific communities of fungi. Plant pathogens were relatively rare, but, under suitable conditions, these can develop rapidly, spread efficiently through the irrigation system and be a threat to the production of high-quality tree seedlings.

scholarly journals Comparative Genomics and Functional Studies of Wheat BED-NLR Loci

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1406
Author(s):  
Clemence Marchal ◽  
Georg Haberer ◽  
Manuel Spannagl ◽  
Cristobal Uauy ◽  
Keyword(s):  
Cell Death ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Functional Studies ◽  
Network Analyses ◽  
Binding Factor ◽  
Localization Signal ◽  
Integrated Domains ◽  
Genomic Regions

Nucleotide-binding leucine-rich-repeat (LRR) receptors (NLRs) with non-canonical integrated domains (NLR-IDs) are widespread in plant genomes. Zinc-finger BED (named after the Drosophila proteins Boundary Element-Associated Factor and DNA Replication-related Element binding Factor, named BED hereafter) are among the most frequently found IDs. Five BED-NLRs conferring resistance against bacterial and fungal pathogens have been characterized. However, it is unknown whether BED-NLRs function in a manner similar to other NLR-IDs. Here, we used chromosome-level assemblies of wheat to explore the Yr7 and Yr5a genomic regions and show that, unlike known NLR-ID loci, there is no evidence for a NLR-partner in their vicinity. Using neighbor-network analyses, we observed that BED domains from BED-NLRs share more similarities with BED domains from single-BED proteins and from BED-containing proteins harboring domains that are conserved in transposases. We identified a nuclear localization signal (NLS) in Yr7, Yr5, and the other characterized BED-NLRs. We thus propose that this is a feature of BED-NLRs that confer resistance to plant pathogens. We show that the NLS was functional in truncated versions of the Yr7 protein when expressed in N. benthamiana. We did not observe cell-death upon the overexpression of Yr7 full-length, truncated, and ‘MHD’ variants in N. benthamiana. This suggests that either this system is not suitable to study BED-NLR signaling or that BED-NLRs require additional components to trigger cell death. These results define novel future directions to further understand the role of BED domains in BED-NLR mediated resistance.

The Role of Provide Survice Small Town in Rural–Urban Linkages for Sustainable Development: A case of rural-urban linkage of Malda district, West Bengal, India

2016 ◽  
Vol 2 (4) ◽  
Author(s):  
Anik Saha
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Institutional Constraints ◽  
Service Development ◽  
Trade Policies ◽  
Trade Networks ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
The City

Rural–urban linkages play a fundamental role in the generation of service, development, health treatment and wealth. Yet, for various reasons the importance of such linkages is not recognized and thus unnoticed in rural economic and trade policies. The present paper investigates infrastructure problem, institutional constraints and dependency rural area on near rural service trade barriers that tend to discourage linkages between rural and urban areas and thus prevent a process of rural empowerment and economic development. The findings of our review indicate that clustering rural and urban areas into regional planning units may create the necessary enabling environment for extensive trade networks and knowledge switch over between the city and the neighbor rural-side. As such, stronger rural–urban linkages could also play a crucial role in fulfill rural areas demand in developing countries.

scholarly journals The ‘Lost Caravan’ of Ma’den Ijafen Revisited: Re-appraising Its Cargo of Cowries, a Medieval Global Commodity

2018 ◽  
Vol 16 (2) ◽  
pp. 125-144 ◽  
Author(s):  
A.C. Christie ◽  
A. Haour
Keyword(s):  
Natural History ◽  
West African ◽  
Medieval Period ◽  
Long Distance ◽  
Shell Size ◽  
Trade Networks ◽  
Ethnographic Interviews ◽  
Environmental Surveys ◽  
Insight Into

AbstractThe lost caravan of Ma’den Ijafen, Mauritania, with its cargo of cowries and brass, is widely discussed in African archaeology, providing significant insight into the nature of long-distance trade in the medieval period. While the brass bars recovered by Théodore Monod during his expedition to the site in 1962 have received considerable attention, the cowrie shells described in his comprehensive publication of the assemblage in 1969 have received much less coverage. This issue was addressed during a recent visit to the Institut Fondamental d’Afrique Noire (IFAN) in Dakar, Senegal in May 2017, when the authors re-examined the shells as part of a wider project which also involved archaeological and environmental surveys in the Maldives, the oft-assumed source of these shells. Examinations of natural history collections of cowries, ethnographic interviews in the Maldives, and environmental surveys in East Africa were also carried out. Drawing on insights from these surveys, we systematically compared the Ma’den Ijafen cowrie assemblage to three others from the Maldives, focussing on four criteria: species composition and diversity, shell size and evidence of modifications. This analysis enabled us to shed new light on the nature of the Ma’den Ijafen cowries and their wider significance to understanding the role of the shells in West African trade networks.

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