De novo indol-3-ylmethyl glucosinolate biosynthesis,and not long-distance transport,contributes to defence of Arabidopsis against powdery mildew

Powdery mildew is a fungal disease that affects a wide range of plants and reduces crop yield worldwide. As obligate biotrophs, powdery mildew fungi manipulate living host cells to suppress defence responses and to obtain nutrients. Members of the plant order Brassicales produce indole glucosinolates that effectively protect them from attack by non-adapted fungi. Indol-3-ylmethyl glucosinolate is constitutively produced in the phloem and transported to epidermal cells for storage. Upon attack, indol-3-ylmethyl glucosinolate is activated by CYP81F2 to provide broad-spectrum defence against fungi. How de novo biosynthesis and transport contribute to defence of powdery mildew-attacked epidermal cells is unknown. Bioassays and glucosinolate analysis demonstrate that GTR glucosinolate transporters are not involved in antifungal defence. Using quantitative live-cell imaging of fluorophore-tagged markers, we show that accumulation of the glucosinolate biosynthetic enzymes CYP83B1 and SUR1 is induced in epidermal cells attacked by the non-adapted barley powdery mildew Blumeria graminis f.sp. hordei. By contrast, glucosinolate biosynthesis is attenuated during interaction with the virulent powdery mildew Golovinomyces orontii. Interestingly, SUR1 induction is delayed during the Golovinomyces orontii interaction. We conclude that epidermal de novo synthesis of indol-3-ylmethyl glucosinolate contributes to CYP81F2-mediated broad-spectrum antifungal resistance and that adapted powdery mildews may target this process.     

Predicted future distribution of the African skimmer in response to a changing climate,land cover and distance from water in the mid-Zambezi Valley

Climate models project a hot and dry future for Southern Africa. In this research, Maximum Entropy was used to model the extent to which climate change, land cover and distance from water edges may influence current and future distribution of the African skimmer in the mid-Zambezi Valley. Global Biodiversity Information Facility data collected between the years 2000–2019 were used to develop the models. Three models were built: one for current distribution and two for future distribution under Representative Concentration Pathways (RCPs) 2.6 and 6.0. Results revealed that annual precipitation and distance from water edges were the most important predictors of habitat suitability for the African skimmer under current and future climate. Temperature and land cover were least important in explaining current and future distribution of the species. The RCP 2.6 predicted future decrease in suitable habitat for the African skimmer in the mid-Zambezi Valley, while RCP 6.0 predicted future increase in suitable habitat for the species. This research conclusively revealed that precipitation and distance from water edges were consistently key predictors of suitable habitat for the African skimmer.     

Internalization of Western Ideals on Appearance and Self-Esteem in Jamaican Undergraduate Students

Culture, Medicine, and Psychiatry - Beauty ideals in the Caribbean are shifting with increased exposure to Western and European standards of appearance. Previous research has shown a consistent...     

CCAAT/enhancer-binding protein beta (C/EBPβ) knockdown reduces inflammation,ER stress,and apoptosis,and promotes autophagy in oxLDL-treated RAW264.7 macrophage cells

Molecular and Cellular Biochemistry - Atherosclerosis is associated with deregulated cholesterol metabolism and formation of macrophage foam cells. CCAAT/enhancer-binding protein beta (C/EBPβ)...     

Response to Preuss and Zuccarello (2020): biological definitions that can be unambiguously applied for red algal parasites

In response to a comment in this issue on our proposal of new terminology to distinguish red algal parasites, we clarify a few key issues. The terms adelphoparasite and alloparasite were previously used to identify parasites that infected close or distant relatives. However, most red algal parasites have only been studied morphologically, and molecular tools have shown that these binary terms do a poor job at representing the range of parasite–host relationships. We recognize the need to clarify inferred misconceptions that appear to be drawing from historical terminology to contaminate our new definitions. We did not intend to replace the term adelphoparasite with neoplastic parasites and the term alloparasites with archaeplastic parasites. Rather, we seek to establish new terms for discussing red algal parasites, based on the retention of a native plastid, a binary biological trait that is relatively easy to identify using modern methods and has biological implications for the interactions between a parasite and its host. The new terminology can better account for the spectrum of relationships and developmental patterns found among the many independently evolved red algal parasites, and it is intended to inspire new research, particularly the role of plastids in the survival and evolution of red algal parasites.     

Gopher Tortoise Demographic Responses to a Novel Disturbance Regime

The long-term viability of gopher tortoise (Gopherus polyphemus) populations is jeopardized by increased urbanization and habitat degradation owing to fire suppression. Because the species' remaining natural habitats in the southeastern United States exist within a mosaic of anthropogenic land uses, it is important to understand demographic responses to contrasting land uses and habitat management regimes. We examined differences in demographic parameters among fire-suppressed sandhill, restored sandhill, and former sandhill (i.e., ruderal) land use-land cover (LULC) types at Archbold Biological Station in south-central Florida, USA. Using Program MARK, we estimated population size, and sex-specific and LULC-specific survivorship based on 6 years of mark-recapture data. We also analyzed individual growth trajectories and clutch sizes to determine whether growth rates or reproductive output differed among LULC types. Tortoises in an open, ruderal field occurred at a higher density (7.79/ha) than in adjacent restored (1.43/ha) or fire-suppressed (0.40/ha) sandhill. Despite this higher density, both adult survivorship and body size were significantly higher in the ruderal field. Furthermore, the larger female body size in the ruderal field likely contributed to increased annual survivorship and slightly larger average clutch sizes. We did not detect offsetting negative demographic effects; in particular, we did not find significant biological or statistical differences in body condition, asymptotic body size, or growth rate among the 3 LULC types. Our results suggest that anthropogenic, grass-dominated land-cover types may be important components of the habitat mosaic currently available to this at-risk species. © 2019 The Wildlife Society.     

Ectomycorrhizal fungal diversity interacts with soil nutrients to predict plant growth despite weak plant-soil feedbacks

Plant and Soil - Plant-soil feedbacks are the result of multiple abiotic and biotic mechanisms. However, few studies have addressed how feedbacks vary based on abiotic context or attempted to...     

The Prebiotic Provenance of Semi-Aqueous Solvents

Origins of Life and Evolution of Biospheres - The numerous and varied roles of phosphorylated organic molecules in biochemistry suggest they may have been important to the origin of life. The...     

A practical guide to DNA metabarcoding for entomological ecologists

1. DNA metabarcoding is a cost-effective species identification approach with great potential to assist entomological ecologists. This review presents a practical guide to help entomological ecologists design their own DNA metabarcoding studies and ensure that sound ecological conclusions can be obtained. 2. The review considers approaches to field sampling, laboratory work, and bioinformatic analyses, with the aim of providing the background knowledge needed to make decisions at each step of a DNA metabarcoding workflow. 3. Although most conventional sampling methods can be adapted to DNA metabarcoding, this review highlights techniques that will ensure suitable DNA preservation during field sampling and laboratory storage. The review also calls for a greater understanding of the occurrence, transportation, and deposition of environmental DNA when applying DNA metabarcoding approaches for different ecosystems. 4. Accurate species detection with DNA metabarcoding needs to consider biases introduced during DNA extraction and PCR amplification, cross-contamination resulting from inappropriate amplicon library preparation, and downstream bioinformatic analyses. Quantifying species abundance with DNA metabarcoding is in its infancy, yet recent studies demonstrate promise for estimating relative species abundance from DNA sequencing reads. 5. Given that bioinformatics is one of the biggest hurdles for researchers new to DNA metabarcoding, several useful graphical user interface programs are recommended for sequence data processing, and the application of emerging sequencing technologies is discussed.