Flaming Phlox and the Ubiquitous Powdery Mildew Disease

2020 ◽  
pp. 1-10
Author(s):  
Coralie Farinas ◽  
Pablo S. Jourdan ◽  
Francesca Peduto Hand
Keyword(s):  
Powdery Mildew ◽  
Molecular Mechanisms ◽  
Ornamental Plants ◽  
Disease Spread ◽  
Evolutionary Potential ◽  
North American Continent ◽  
The North ◽  
Horticultural Traits ◽  
Ontogenic Resistance

Phlox is a diverse genus of ornamental plants that is native to the North American continent. These popular plants, which are known for flowers with “the color of glowing flame”, are particularly appreciated in naturalistic arrangements and increasingly emphasized in native gardens for their ability to attract pollinators. Despite the plant’s popularity, the main limitation to its cultivation is the fungal disease powdery mildew (PM). Hence, cultivars deployed through the years have been selected not just for desirable horticultural traits but also for resistance to PM. Although some studies on the Phlox-PM pathosystem have begun to unravel the mechanisms underpinning host-pathogen interactions, numerous questions remain unanswered, including what are the genes involved in the retarded senescence of the infected host tissue, what are the molecular mechanisms associated with the host ontogenic resistance, and what is the role of phytohormones in the resistance of Phlox to PM? PM pathogens, already predominant on Phlox, are now likely to be ubiquitous due to the exchange of plants throughout the world. Research into the genetic diversity of Phlox-PM populations will help identify the routes of disease spread and evolutionary potential of the pathogens. Here, we review what is known about Phlox and the PM disease, and we identify knowledge gaps that have yet to be addressed.

scholarly journals Overexpression of the Apple (Malus× domestica) MdERF100 in Arabidopsis Increases Resistance to Powdery Mildew

2021 ◽  
Vol 22 (11) ◽  
pp. 5713
Author(s):  
Yiping Zhang ◽  
Li Zhang ◽  
Hai Ma ◽  
Yichu Zhang ◽  
Xiuming Zhang ◽  
...  
Keyword(s):  
Stress Response ◽  
Powdery Mildew ◽  
Malus Domestica ◽  
Molecular Mechanisms ◽  
Powdery Mildew Resistance ◽  
Bimolecular Fluorescence Complementation ◽  
Bhlh Protein ◽  
Mildew Resistance ◽  
Sa Signaling

APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factors play important roles in plant development and stress response. Although AP2/ERF genes have been extensively investigated in model plants such as Arabidopsis thaliana, little is known about their role in biotic stress response in perennial fruit tree crops such as apple (Malus × domestica). Here, we investigated the role of MdERF100 in powdery mildew resistance in apple. MdERF100 localized to the nucleus but showed no transcriptional activation activity. The heterologous expression of MdERF100 in Arabidopsis not only enhanced powdery mildew resistance but also increased reactive oxygen species (ROS) accumulation and cell death. Furthermore, MdERF100-overexpressing Arabidopsis plants exhibited differential expressions of genes involved in jasmonic acid (JA) and salicylic acid (SA) signaling when infected with the powdery mildew pathogen. Additionally, yeast two-hybrid and bimolecular fluorescence complementation assays confirmed that MdERF100 physically interacts with the basic helix–loop–helix (bHLH) protein MdbHLH92. These results suggest that MdERF100 mediates powdery mildew resistance by regulating the JA and SA signaling pathways, and MdbHLH92 is involved in plant defense against powdery mildew. Overall, this study enhances our understanding of the role of MdERF genes in disease resistance, and provides novel insights into the molecular mechanisms of powdery mildew resistance in apple.

The Stamp Act Crisis in the British West Indies

1977 ◽  
Vol 11 (2) ◽  
pp. 203-221 ◽  
Author(s):  
Donna J. Spindel
Keyword(s):  
North American ◽  
West Indies ◽  
West Indians ◽  
British West Indies ◽  
American Continent ◽  
North American Continent ◽  
The North ◽  
Stamp Act

Traditionally, colonial scholars have focussed their attention on the North American continent, where dramatic conflicts with Britain culminated in Revolution. No major article or book has yet dealt with British West Indians as active participants in the pre-Revolutionary struggle. This study attempts to correct that situation. Focussing on the Stamp Act crisis, it seeks to clarify the role of island colonists during the pre-war period and argues for a comprehensive appraisal of that role.

Connecting the Land Surface to Droughts: How Transpiration, Canopy Evaporation, and Ground Evaporation Impact Droughts Across the North American Continent

2021 ◽  
Author(s):  
Tyler Harrington ◽  
Christopher Skinner ◽  
Jesse Nusbaumer
Keyword(s):  
North America ◽  
Land Surface ◽  
Summer Precipitation ◽  
North American Continent ◽  
Surface Moisture ◽  
Community Land Model ◽  
The North ◽  
Desert Southwest ◽  
The Individual

<p>Land surface moisture plays a crucial role in precipitation patterns across the globe. Evapotranspiration (the combination of ground evaporation (E), canopy evaporation (I), and transpiration (T)) from the land surface can influence precipitation through local recycling and the propagation of moisture to downwind regions. However, the role of the land surface and of T, E, and I individually in these two processes are not well understood and limit our understanding of the role of the land surface for both drought onset and intensification. Here we use a version of the Community Earth System Model (CESM1.2 with the Community Atmosphere Model CAM5 and the Community Land Model CLM5) with online water tracers to directly track and quantify the movement of T, E and I moisture across North America for the 1985–2015 period. Initial findings suggest that over 50% of summer precipitation for much of central and northern US and Canada comes from the land surface. The tracers also suggest that, with the exception of the US west coast and desert southwest, 40-60% of land precipitation across the continent comes from the T component. The connection between land surface moisture and drought episodes are examined for different regions of North America. The individual roles of T, E, and I in shaping droughts are also examined.</p>

The Role of Desire, Opportunity, and Capacity in the Revitalization of Native American Languages

2013 ◽  
Vol 10 (3) ◽  
pp. 367-381
Author(s):  
Erin Flynn Haynes
Keyword(s):  
Native American ◽  
Language Revitalization ◽  
The United States ◽  
Indigenous Languages ◽  
Language Loss ◽  
American Continent ◽  
Native American Languages ◽  
North American Continent ◽  
The North

Language loss affects many Native American communities in the United States, threatening the vitality of the indigenous languages of the North American continent. This article discusses current and historic reasons for this loss and provides an overview of language revitalization with reference to a framework of desire, opportunity,and capacity.

scholarly journals Combatting Rose Rosette Disease with Volunteer Involvement in the Monitoring Effort

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 601-603 ◽  
Author(s):  
Kevin Ong ◽  
Madalyn Shires ◽  
Holly Jarvis Whitaker ◽  
Jennifer Olson ◽  
Joseph LaForest ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Public Awareness ◽  
Scientific Work ◽  
Disease Spread ◽  
North American Continent ◽  
The North ◽  
Monitoring Effort ◽  
Rose Rosette ◽  
Rose Rosette Disease

Rose rosette disease (RRD) was first reported on the North American continent in the early 1940s. In 2011, the causal agent of this disease was identified and described—the Rose rosette virus (RRV). In the last 10 years, RRD has gained widespread notoriety because of disease symptoms appearing on many roses which are used frequently in landscape plantings, both commercial and residential. Much of the prior scientific work on this disease was carried out on the multiflora rose. Currently, the disease issues are on cultivated roses within which no cultivar has been confirmed to be resistant. There is an information gap in our knowledge of the pathogen, vector, and the disease on cultivated roses. Our goals for this project are to seek and identify potential disease tolerance or resistance in roses and increasing public awareness and knowledge of RRD with the purpose of reducing the disease spread with best management practices. Outreach and volunteer recruitment are key activities used to provide scientifically sound information, to establish the current disease range and to actively gather observational reports of RRD to identify resistant rose sources. Elements of these activities include educational meetings, factsheets, posters, and workshops where RRD symptoms recognition is emphasized. A web-based reporting tool was developed to capture observations from volunteers while continually keeping them engaged. It is hoped that through outreach and the collective monitoring effort, researchers will have access to information that contributes to a better understanding of RRD and will find disease-resistant roses that could be used in breeding programs for the continued enjoyment of roses.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

Mesophyll conductance: the leaf corridors for photosynthesis

2020 ◽  
Vol 48 (2) ◽  
pp. 429-439 ◽  
Author(s):  
Jorge Gago ◽  
Danilo M. Daloso ◽  
Marc Carriquí ◽  
Miquel Nadal ◽  
Melanie Morales ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Main Role ◽  
Mesophyll Conductance ◽  
Future Studies ◽  
Cell Structures ◽  
Leaf Tissues ◽  
Change Framework ◽  
Chloroplast Stroma

Besides stomata, the photosynthetic CO2 pathway also involves the transport of CO2 from the sub-stomatal air spaces inside to the carboxylation sites in the chloroplast stroma, where Rubisco is located. This pathway is far to be a simple and direct way, formed by series of consecutive barriers that the CO2 should cross to be finally assimilated in photosynthesis, known as the mesophyll conductance (gm). Therefore, the gm reflects the pathway through different air, water and biophysical barriers within the leaf tissues and cell structures. Currently, it is known that gm can impose the same level of limitation (or even higher depending of the conditions) to photosynthesis than the wider known stomata or biochemistry. In this mini-review, we are focused on each of the gm determinants to summarize the current knowledge on the mechanisms driving gm from anatomical to metabolic and biochemical perspectives. Special attention deserve the latest studies demonstrating the importance of the molecular mechanisms driving anatomical traits as cell wall and the chloroplast surface exposed to the mesophyll airspaces (Sc/S) that significantly constrain gm. However, even considering these recent discoveries, still is poorly understood the mechanisms about signaling pathways linking the environment a/biotic stressors with gm responses. Thus, considering the main role of gm as a major driver of the CO2 availability at the carboxylation sites, future studies into these aspects will help us to understand photosynthesis responses in a global change framework.

The Inherited Past of the Broch: On Antiquarian Discourse and Contemporary Archaeology

2002 ◽  
Vol 24 (1) ◽  
pp. 1-20 ◽  
Author(s):  
ANDREW BAINES
Keyword(s):  
Material Culture ◽  
19Th Century ◽  
Academic Language ◽  
Contemporary Archaeology ◽  
The North

In reading archaeological texts, we expect to be engaged in a characteristically archaeological discourse, with a specific and recognisable structure and vocabulary. In evaluating the published work of 19th Century antiquarians, we will inevitably look for points of contact between their academic language and our own; success or failure in the identification of such points of contact may prompt us to recognise a nascent archaeology in some writings, while dismissing others as naïve or absurd. With this point in mind, this paper discusses the written and material legacies of three 19th Century antiquarians in the north of Scotland who worked on a particular monument type, the broch. The paper explores the degree to which each has been admitted as an influence on the development of the broch as a type. It then proceeds to compare this established typology with the author's experiences, in the field, of the sites it describes. In doing so, the paper addresses wider issues concerning the role of earlier forms of archaeological discourse in the development of present day archaeological classifications of, and of the problems of reconciling such classifications with our experiences of material culture.

Training of Village Teachers in Vilna Educational District in the 1860s and 1870s

2020 ◽  
Vol 58 ◽  
pp. 181-192
Author(s):  
Anna A. Komzolova
Keyword(s):  
Educational Reform ◽  
Rural Teachers ◽  
Cultural Brokers ◽  
The North ◽  
Central Russia ◽  
Russian Intelligentsia ◽  
Trained Teachers ◽  
The Village ◽  
North Western

One of the results of the educational reform of the 1860s was the formation of the regular personnel of village teachers. In Vilna educational district the goal was not to invite teachers from central Russia, but to train them on the spot by establishing special seminaries. Trained teachers were supposed to perform the role of «cultural brokers» – the intermediaries between local peasants and the outside world, between the culture of Russian intelligentsia and the culture of the Belarusian people. The article examines how officials and teachers of Vilna educational district saw the role of rural teachers as «cultural brokers» in the context of the linguistic and cultural diversity of the North-Western Provinces. According to them, the graduates of the pedagogical seminaries had to remain within the peasant estate and to keep in touch with their folk «roots». The special «mission» of the village teachers was in promoting the ideas of «Russian elements» and historical proximity to Russia among Belarusian peasants.

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