Contribution of Pollinator-Mediated Crops to Nutrients in the Human Food Supply

The contribution of nutrients from animal pollinated world crops has not previously been evaluated as a biophysical measure for the value of pollination services. This study evaluates the nutritional composition of animal-pollinated world crops. We calculated pollinator dependent and independent proportions of different nutrients of world crops, employing FAO data for crop production, USDA data for nutritional composition, and pollinator dependency data according to Klein et al. (2007). Crop plants that depend fully or partially on animal pollinators contain more than 90% of vitamin C, the whole quantity of Lycopene and almost the full quantity of the antioxidants β-cryptoxanthin and β-tocopherol, the majority of the lipid, vitamin A and related carotenoids, calcium and fluoride, and a large portion of folic acid. Ongoing pollinator decline may thus exacerbate current difficulties of providing a nutritionally adequate diet for the global human population

An interactome-centered protein discovery approach reveals novel components involved in mitosome function and homeostasis in giardia lamblia

Protozoan parasites of the genus Giardia are highly prevalent globally, and infect a wide range of vertebrate hosts including humans, with proliferation and pathology restricted to the small intestine. This narrow ecological specialization entailed extensive structural and functional adaptations during host-parasite co-evolution. An example is the streamlined mitosomal proteome with iron-sulphur protein maturation as the only biochemical pathway clearly associated with this organelle. Here, we applied techniques in microscopy and protein biochemistry to investigate the mitosomal membrane proteome in association to mitosome homeostasis. Live cell imaging revealed a highly immobilized array of 30–40 physically distinct mitosome organelles in trophozoites. We provide direct evidence for the single giardial dynamin-related protein as a contributor to mitosomal morphogenesis and homeostasis. To overcome inherent limitations that have hitherto severely hampered the characterization of these unique organelles we applied a novel interaction-based proteome discovery strategy using forward and reverse protein co-immunoprecipitation. This allowed generation of organelle proteome data strictly in a protein-protein interaction context. We built an initial Tom40-centered outer membrane interactome by co-immunoprecipitation experiments, identifying small GTPases, factors with dual mitosome and endoplasmic reticulum (ER) distribution, as well as novel matrix proteins. Through iterative expansion of this protein-protein interaction network, we were able to i) significantly extend this interaction-based mitosomal proteome to include other membrane-associated proteins with possible roles in mitosome morphogenesis and connection to other subcellular compartments, and ii) identify novel matrix proteins which may shed light on mitosome-associated metabolic functions other than Fe-S cluster biogenesis. Functional analysis also revealed conceptual conservation of protein translocation despite the massive divergence and reduction of protein import machinery in Giardia mitosomes

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Fungicides Cuprozin Progress and SWITCH Modulate Primary and Specialized Metabolites of Strawberry Fruits

Voß A-C, Eilers EJ, Müller C. Fungicides Cuprozin Progress and SWITCH Modulate Primary and Specialized Metabolites of Strawberry Fruits. Journal of Agricultural and Food Chemistry. 2023.Numerous pesticides, including fungicides, are applied every year to crop plants. However, such application may affect the plant metabolism and thus crop quality. Strawberry is an economically important crop, but the fruits are highly susceptible, especially to fungal diseases. In the present study, the effects of two fungicides, Cuprozin progress and SWITCH, on the metabolism of two cultivars and the wild strawberry were tested, focusing on primary (amino acids, (in)organic acids, sugars, total phenolics) and specialized metabolites (aroma volatiles), which determine the fruit flavor. The fungicide treatment significantly affected 11 out of 57 metabolites, while 20 of those differed between strawberry types and 27 were affected by the interaction of both factors. Given these modifications in metabolites in response to the treatments, the taste and quality of the strawberries may pronouncedly change when plants are treated with fungicides

Floral volatiles evoke partially similar responses in both florivores and pollinators and are correlated with non-volatile reward chemicals

Sasidharan R, Junker RR, Eilers EJ, Müller C. Floral volatiles evoke partially similar responses in both florivores and pollinators and are correlated with non-volatile reward chemicals. Annals of Botany. 2023.**Background** Plants often use floral displays to attract mutualists and prevent antagonist attacks. Chemical displays detectable from a distance include attractive or repellent floral volatile organic compounds (FVOCs). Locally, visitors perceive contact chemicals including nutrients but also deterrent or toxic constituents of pollen and nectar. FVOC and pollen chemical composition may vary intra- and interspecifically. For certain pollinator and florivore species, responses towards these compounds are studied in specific plant systems; yet we lack a synthesis of general patterns comparing these two groups and insights into potential correlations between FVOC and pollen chemodiversity. **Scope** We reviewed how FVOCs and non-volatile floral chemical displays, i.e., pollen nutrients and toxins, vary in composition and affect the detection and behaviour of insect visitors. Moreover, we used meta-analyses to evaluate the detection of and responses towards FVOCs by pollinators vs. florivores within the same plant genera. We also tested whether the chemodiversity of FVOCs, pollen nutrients and toxins are correlated and hence mutually informative. **Key Results** According to available data, florivores could detect more FVOCs than pollinators. Frequently tested FVOCs were often reported as pollinator-attractive and florivore-repellent. Among FVOCs tested on both visitor groups, there were a higher number of attractive than repellent compounds. FVOC and pollen toxin richness correlated negatively, indicating trade-offs, while a marginal positive correlation between pollen protein amount and toxin richness was observed. **Conclusions** Plants face critical trade-offs, as floral chemicals mediate similar information to both mutualists and antagonists, particularly through attractive, and fewer repellent, FVOCs. Furthermore, florivores may detect more FVOCs, whose richness is correlated to reward chemical richness. FVOC chemodiversity is potentially informative of reward traits. To better understand the ecological processes shaping floral chemical displays, more research is needed on floral antagonists of diverse plant species, and on the role of floral chemodiversity towards visitor responses

Contribution of pollinator-mediated crops to nutrients in the human food supply.

The contribution of nutrients from animal pollinated world crops has not previously been evaluated as a biophysical measure for the value of pollination services. This study evaluates the nutritional composition of animal-pollinated world crops. We calculated pollinator dependent and independent proportions of different nutrients of world crops, employing FAO data for crop production, USDA data for nutritional composition, and pollinator dependency data according to Klein et al. (2007). Crop plants that depend fully or partially on animal pollinators contain more than 90% of vitamin C, the whole quantity of Lycopene and almost the full quantity of the antioxidants β-cryptoxanthin and β-tocopherol, the majority of the lipid, vitamin A and related carotenoids, calcium and fluoride, and a large portion of folic acid. Ongoing pollinator decline may thus exacerbate current difficulties of providing a nutritionally adequate diet for the global human population

Hypothesized function, abundance external morphology and dendritic structure (ODS: outer dendritic segment, TB: tubular body) of sensilla on antennae (A) and maxillary (M) and labial palps (L) in <i>Melolontha melolontha</i> larvae.

<p>Hypothesized function, abundance external morphology and dendritic structure (ODS: outer dendritic segment, TB: tubular body) of sensilla on antennae (A) and maxillary (M) and labial palps (L) in <i>Melolontha melolontha</i> larvae.</p