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Deposition of silica in sorghum root endodermis modifies the chemistry of associated lignin.

Silica aggregates at the endodermis of sorghum roots. Aggregation follows a spotted pattern of locally deposited lignin at the inner tangential cell walls. Autofluorescence microscopy suggests that non-silicified (-Si) lignin spots are composed of two distinct concentric regions of varied composition. To highlight variations in lignin chemistry, we used Raman microspectroscopy to map the endodermal cell wall and silica aggregation sites in sorghum roots grown hydroponically with or without Si amendment. In +Si samples, the aggregate center was characterized by typical lignin monomer bands surrounded by lignin with a low level of polymerization. Farther from the spot, polysaccharide concentration increased and soluble silicic acid was detected in addition to silica bands. In -Si samples, the main band at the spot center was assigned to lignin radicals and highly polymerized lignin. Both +Si and -Si loci were enriched by aromatic carbonyls. We propose that at silica aggregation sites, carbonyl rich lignin monomers are locally exported to the apoplast. These monomers are radicalized and polymerized into short lignin polymers. In the presence of silicic acid, bonds typically involved in lignin extension, bind to silanols and nucleate silica aggregates near the monomer extrusion loci. This process inhibits further polymerization of lignin. In -Si samples, the monomers diffuse farther in the wall and crosslink with cell wall polymers, forming a ring of dense lignified cell wall around their export sites.

Значение масличных культур в повышении устойчивости растениеводства в природно-климатических условиях Южного Урала и Зауралья

The high aridity of the climate of the Southern Urals and Beyond the Urals, where the Kurgan and Chelyabinsk regions are located, forces farmers to constantly look for ways to increase the sustainability of crop production. It is easier to tolerate drought due to their biological characteristics and thereby stabilize the production of oilseeds, while the high domestic and export demand for oilseeds contribute to the fact that in Russia the acreage of sunflower, rapeseed, soybean and oilseed flax is increasing every year. Their cultivation in combination with grain allows you to distribute the organizational load during field work more evenly over time, use technical and labor resources more efficiently, reduce the need for equipment and depreciation. The purpose of the study is to determine the importance in increasing the economic and environmental sustainability of crop production of oilseeds, the most cost-effective for cultivation in the conditions of the Southern Urals and Trans-Urals. The tasks are to analyze weather conditions, the results of variety testing at state export sites and production data on the cultivation of oilseeds in the Kurgan and Chelyabinsk regions. The methods of monographic, mathematical, statistical analysis of data from scientific literature, open statistical sources, agronomic and economic reports of agricultural enterprises were used. The scientific novelty of the research consists in studying the importance of oilseeds in increasing the sustainability of crop production in connection with changes in the natural and climatic conditions of agricultural production. The results of the study showed that high prices for oilseeds, stabilizing the incomes of enterprises, contributed to the expansion of the acreage of oilseeds. It was revealed that with the same level of costs for the cultivation of oilseeds, material resources are used more efficiently compared to grain. It was found that under the prevailing weather conditions and prices for oilseeds during the years of research, the economic stability of crop production among oilseeds was stabilized, first of all, by the most drought-resistant sunflower. The yield of grain crops in the Kurgan and Chelyabinsk regions over the past five, including acutely arid, years has tended to decrease, and sunflower – to increase and less fluctuations over the years.

CmCNIH1 improves salt tolerance by influencing the trafficking of CmHKT1;1 in pumpkin.

Pumpkin is often used as a rootstock for other Cucurbitaceae crops due to its resistance to soil-borne diseases and abiotic stress. Pumpkin rootstocks use a sodium transporter (CmHKT1;1) to promote the transport of Na+ from the shoot to the root effectively and improve the salt tolerance of the scion. However, the molecular regulatory mechanisms that influence the activity of CmHKT1;1 during salt stress response remain unknown. In this study, CmCNIH1, a cornichon homolog, was identified as a potential cargo receptor for CmHKT1;1. Yeast two-hybrid, biomolecular fluorescence complementation and luciferase complementary assays demonstrated that CmCNIH1 and CmHKT1;1 could interact. CmCNIH1 was a key component of the cellular vesicle transport machinery located in the endoplasmic reticulum (ER), ER export site and Golgi apparatus. A CmCNIH1 knockout mutant was more sensitive to salt stress than the wild-type (WT). In addition, ion homeostasis was disrupted in cmcnih1 mutants, which had higher Na+ and lower K+ content in shoots and roots than the WT. Two-electrode voltage-clamp experiment displayed that CmCNIH1 could not influence the Na+ current that passed through the plasma membrane (PM) in CmHKT1;1-expressing Xenopus laevis oocytes. Data from co-localization assays indicated that intact CmCNIH1 protein could alter the subcellular localization of CmHKT1;1 in tobacco leaf, pumpkin root and yeast. In summary, CmCNIH1 may function as a cargo receptor that regulates the localization of CmHKT1;1 to the PM to improve salt tolerance in pumpkin.

The Role of E-Bike in Discovering Geodiversity and Geoheritage

This study analyzed the challenges and benefits of the identification and promotion of a long-distance cycleway in high mountain areas with the aim of promoting Alpine eco- and geo-tourism. We also investigated the role of e-biking in discovering local geodiversity and geoheritage in a sustainable way. In particular, we focused on the path from Bormio to the Forni Glacier (Upper Valtellina, Italy), analyzed within the framework of the “E-bike” Interreg project. We performed a detailed analysis to select the points of environmental–geological interest (POIs), with a focus on geoheritage sites to increase the knowledge of the natural heritage of the area. Since these sites are widespread in the study area, within the frame of the “E-bike” project, we selected only the most exemplary ones, covering a wide spectrum of attractions, from a moving geosite (i.e., landslide) to a paradigmatic example of the effects of climate change (glacier). The “E-bike” path represents in its entirety a great opportunity to visit mountain and high-mountain landscapes, even for inexperienced mountain bikers, and to enjoy places rich in naturalistic and cultural values. Our interdisciplinary approach allows visitors to identify the sites of interest and export the structure of the project in different environmental and human contexts.

Cargo control of bulky carrier formation during collagen export.

Procollagen, is exported from the endoplasmic reticulum (ER) in the form of rigid 300 nm long triple-helical structures. Surprisingly, the export machinery for procollagen relies on COPII components, which typically form lipid vesicle carriers of about 80 nm, much smaller than procollagen cargos. Recently the ER-resident protein TANGO1 has been shown to organize into rings around COPII coats at ER exit sites (ERES), suggesting it plays a key role in the formation of large carriers. Here we propose a continuum biophysical model to study the dynamic interplay between the ER membrane, procollagen, COPII, and TANGO1 during the formation of a bulky carrier. Our model couples Helfrich bending energy of lipid membranes to the thermodynamic contribution of two interacting membrane-bound species, namely COPII and TANGO1. Our results show that TANGO1 stabilizes incomplete buds by self-organizing into rings around COPII domains, as observed experimentally. We then tested different mechanisms hypothesized to contribute to the formation of bulky carriers compatible with procollagen export, and showed that their coordinated action facilitates the formation of carriers. Our findings suggests that TANGO1 not only serves as a mechanical element of ER export sites, but might also play an important coordinating role in the genesis of procollagen carriers.

Ceramide chain length-dependent protein sorting into selective endoplasmic reticulum exit sites.

Protein sorting in the secretory pathway is crucial to maintain cellular compartmentalization and homeostasis. In addition to coat-mediated sorting, the role of lipids in driving protein sorting during secretory transport is a longstanding fundamental question that still remains unanswered. Here, we conduct 3D simultaneous multicolor high-resolution live imaging to demonstrate in vivo that newly synthesized glycosylphosphatidylinositol-anchored proteins having a very long chain ceramide lipid moiety are clustered and sorted into specialized endoplasmic reticulum exit sites that are distinct from those used by transmembrane proteins. Furthermore, we show that the chain length of ceramide in the endoplasmic reticulum membrane is critical for this sorting selectivity. Our study provides the first direct in vivo evidence for lipid chain length-based protein cargo sorting into selective export sites of the secretory pathway.

Dynamic Capture and Release of Endoplasmic Reticulum Exit Sites by Golgi Stacks in Arabidopsis.

SummaryProtein transport from the endoplasmic reticulum (ER) to Golgi stacks is mediated by the coat protein complex COPII, which is assembled at an ER subdomain called ER exit site (ERES). However, the dynamic relationship between ERESs and Golgi stacks is unknown. Here, we propose a dynamic capture-and-release model of ERESs by Golgi stacks in Arabidopsis thaliana. Using variable-angle epifluorescence microscopy with high-temporal-resolution imaging, COPII-component-bound ERESs were detected as punctate structures with sizes of 300–500 nm. Some punctate ERESs are distributed on ER tubules and sheet rims, whereas others gather around a Golgi stack in an ER-network cavity to form a beaded-ring structure. Free ERESs that wander into an ER cavity are captured by a Golgi stack in a cytoskeleton-independent manner. Then, they are released by the Golgi stack for recycling. The dynamic ERES cycling might contribute to efficient transfer of de novo synthesized cargo proteins from the ER to Golgi stacks.

ER arrival sites associate with ER exit sites to create bidirectional transport portals.

COPI vesicles mediate Golgi-to-ER recycling, but COPI vesicle arrival sites at the ER have been poorly defined. We explored this issue using the yeast Pichia pastoris. ER arrival sites (ERAS) can be visualized by labeling COPI vesicle tethers such as Tip20. Our results place ERAS at the periphery of COPII-labeled ER export sites (ERES). The dynamics of ERES and ERAS are indistinguishable, indicating that these structures are tightly coupled. Displacement or degradation of Tip20 does not alter ERES organization, whereas displacement or degradation of either COPII or COPI components disrupts ERAS organization. We infer that Golgi compartments form at ERES and then produce COPI vesicles to generate ERAS. As a result, ERES and ERAS are functionally linked to create bidirectional transport portals at the ER-Golgi interface. COPI vesicles likely become tethered while they bud, thereby promoting efficient retrograde transport. In mammalian cells, the Tip20 homologue RINT1 associates with ERES, indicating possible conservation of the link between ERES and ERAS.

3D electron tomographic and biochemical analysis of ER, Golgi and trans Golgi network membrane systems in stimulated Venus flytrap (Dionaea muscipula) glandular cells

BackgroundThe insect-trapping leaves of Dionaea muscipula provide a model for studying the secretory pathway of an inducible plant secretory system. The leaf glands were induced with bovine serum albumin to secrete proteases that were characterized via zymogram activity gels over a 6-day period. The accompanying morphological changes of the endoplasmic reticulum (ER) and Golgi were analyzed using 3D electron tomography of glands preserved by high-pressure freezing/freeze substitution methods.ResultsSecretion of multiple cysteine and aspartic proteases occurred biphasically. The majority of the Golgi was organized in clusters consisting of 3–6 stacks surrounded by a cage-like system of ER cisternae. In these clusters, all Golgi stacks were oriented with their cis-most C1 cisterna facing an ER export site. The C1 Golgi cisternae varied in size and shape consistent with the hypothesis that they form de novo. Following induction, the number of ER-bound polysomes doubled, but no increase in COPII vesicles was observed. Golgi changes included a reduction in the number of cisternae per stack and a doubling of cisternal volume without increased surface area. Polysaccharide molecules that form the sticky slime cause swelling of the trans and trans Golgi network (TGN) cisternae. Peeling of the trans-most cisternae gives rise to free TGN cisternae. One day after gland stimulation, the free TGNs were frequently associated with loose groups of oriented actin-like filaments which were not seen in any other samples.ConclusionsThese findings suggest that the secretory apparatus of resting gland cells is “overbuilt” to enable the cells to rapidly up-regulate lytic enzyme production and secretion in response to prey trapping.

ANÁLISE DE VIABILIDADE DOS CUSTOS PARA A REATIVAÇÃO DO TERMINAL DE CONCHAS NA HIDROVIA TIETÊ PARANÁ

O transporte de grãos da produção até seus locais de transformação e/ou exportação tem no transporte sua maior dificuldade na cadeia de suprimentos. Apresentando a estrutura atual da Hidrovia Tiete-Paraná e, caracterizando os elementos de um projeto hidroviário. Este artigo teve como objetivo avaliar os custos com a reativação do terminal hidroviário localizado na cidade de Conchas/SP, apresentando suas vantagens, desvantagens e sua viabilidade no tocante aos custos, quando comparado e somado às despesas de transbordo e operação que ocorrem a partir da utilização dos modais rodoviário e ferroviário hoje, buscando alternativas para minimizar o impacto dos valores nessa movimentação, além da verificação do valor a desembolsar pela reativação desse terminal hidroviário. Os resultados indicam que a utilização trecho da Hidrovia Tiete-Paraná que liga Pederneiras/SP - Conchas/SP, permitirá além de uma significativa redução dos custos com o transporte, uma importante mitigação da emissão de GEE, que favoreceriam ao aumento da competitividade da produção brasileira.

Les sites de production des jarres de stockage vietnamiennes pour le commerce maritime, du XVIe au XVIIIe siècle : état de la recherche

Between the 16th and 18th century, Vietnamese ceramic products, including large storage jars, are found among the artefacts on board Chinese merchant ships. Whether these jars are meant to be traded or are used for daily life aboard ships, they travel in the hands of Chinese merchants and tell us about particular aspects of the maritime trading economy. By the end of the 15th century, Vietnamese productions, including storage jars, appeared alongside Chinese ceramics at Southeast Asian export sites, as well as along the routes of international maritime trade. Their production sites are now well known thanks to the many excavations carried out for the past twenty years, but the role of these jars and all the agents that led them from the production centres of the Red River Delta and the centre of Vietnam to distribution sites are yet to be determined. We present here some of the known production sites in the north and centre of Vietnam, and an analysis of the quasi-absence of signs of storage jar production at the kiln sites linked to international ceramic trade.

Dominant role of eddies and filaments in the offshore transport of carbon and nutrients in the California Current System

AbstractThe coastal upwelling region of the California Current System (CalCS) is a well‐known site of high productivity and lateral export of nutrients and organic matter, yet neither the magnitude nor the governing processes of this offshore transport are well quantified. Here we address this gap using a high‐resolution (5 km) coupled physical‐biogeochemical numerical simulation (ROMS). The results reveal (i) that the offshore transport is a very substantial component of any material budget in this region, (ii) that it reaches more than 800 km into the offshore domain, and (iii) that this transport is largely controlled by mesoscale processes, involving filaments and westward propagating eddies. The process starts in the nearshore areas, where nutrient and organic matter‐rich upwelled waters pushed offshore by Ekman transport are subducted at the sharp lateral density gradients of upwelling fronts and filaments located at ∼25–100 km from the coast. The filaments are very effective in transporting the subducted material further offshore until they form eddies at their tips at about 100–200 km from the shore. The cyclonic eddies tend to trap the cold, nutrient, and organic matter‐rich waters of the filaments, whereas the anticyclones formed nearby encapsulate the low nutrient and low organic matter waters around the filament. After their detachment, both types of eddies propagate further in offshore direction, with a speed similar to that of the first baroclinic mode Rossby waves, providing the key mechanism for long‐range transport of nitrate and organic matter from the coast deep into the offshore environment.

A Novel Trypanosoma cruzi Protein Associated to the Flagellar Pocket of Replicative Stages and Involved in Parasite Growth.

The flagellar pocket constitutes an active and strategic site in the body of trypanosomatids (i.e. parasitic protozoa that cause important human and/or livestock diseases), which participates in several important processes such as cell polarity, morphogenesis and replication. Most importantly, the flagellar pocket is the unique site of surface protein export and nutrient uptake in trypanosomatids, and thus constitutes a key portal for the interaction with the host. In this work, we identified and characterized a novel Trypanosoma cruzi protein, termed TCLP 1, that accumulates at the flagellar pocket area of parasite replicative forms, as revealed by biochemical, immuno-cytochemistry and electron microscopy techniques. Different in silico analyses revealed that TCLP 1 is the founding member of a family of chimeric molecules restricted to trypanosomatids bearing, in addition to eukaryotic ubiquitin-like and protein-protein interacting domains, a motif displaying significant structural homology to bacterial multi-cargo chaperones involved in the secretion of virulence factors. Using the fidelity of an homologous expression system we confirmed TCLP 1 sub-cellular distribution and showed that TCLP 1-over-expressing parasites display impaired survival and accelerated progression to late stationary phase under starvation conditions. The reduced endocytic capacity of TCLP 1-over-expressors likely underlies (at least in part) this growth phenotype. TCLP 1 is involved in the uptake of extracellular macromolecules required for nutrition and hence in T. cruzi growth. Due to the bacterial origin, sub-cellular distribution and putative function(s), we propose TCLP 1 and related orthologs in trypanosomatids as appealing therapeutic targets for intervention against these health-threatening parasites.

Single-cell imaging of Wnt palmitoylation by the acyltransferase porcupine

Wnts are secreted palmitoylated glycoproteins that are important in embryonic development and human cancers. Here we report a method for imaging the palmitoylated form of Wnt proteins with subcellular resolution using clickable bioorthogonal fatty acids and in situ proximity ligation. Palmitoylated Wnt3a is visualized throughout the secretory pathway and trafficks to multivesicular bodies that act as export sites in secretory cells. We establish that glycosylation is not required for Wnt3a palmitoylation, which is necessary but not sufficient for Wnt3a secretion. Wnt3a is palmitoylated by fatty acids 13-16 carbons in length at Ser209 but not at Cys77, consistent with a slow turnover rate. We find that porcupine (PORCN) itself is palmitoylated, demonstrating what is to our knowledge the first example of palmitoylation of an MBOAT protein, and this modification partially regulates Wnt palmitoylation and signaling. Our data reveal the role of O-palmitoylation in Wnt signaling and suggest another layer of cellular control over PORCN function and Wnt secretion.

The Cytosolic Nucleoprotein of the Plant-Infecting Bunyavirus Tomato Spotted Wilt Recruits Endoplasmic Reticulum–Resident Proteins to Endoplasmic Reticulum Export Sites

In contrast with animal-infecting viruses, few known plant viruses contain a lipid envelope, and the processes leading to their membrane envelopment remain largely unknown. Plant viruses with lipid envelopes include viruses of the Bunyaviridae, which obtain their envelope from the Golgi complex. The envelopment process is predominantly dictated by two viral glycoproteins (Gn and Gc) and the viral nucleoprotein (N). During maturation of the plant-infecting bunyavirus Tomato spotted wilt, Gc localizes at endoplasmic reticulum (ER) membranes and becomes ER export competent only upon coexpression with Gn. In the presence of cytosolic N, Gc remains arrested in the ER but changes its distribution from reticular into punctate spots. Here, we show that these areas correspond to ER export sites (ERESs), distinct ER domains where glycoprotein cargo concentrates prior to coat protein II vesicle-mediated transport to the Golgi. Gc concentration at ERES is mediated by an interaction between its cytoplasmic tail (CT) and N. Interestingly, an ER-resident calnexin provided with Gc-CT was similarly recruited to ERES when coexpressed with N. Furthermore, disruption of actin filaments caused the appearance of a larger amount of smaller ERES loaded with N-Gc complexes, suggesting that glycoprotein cargo concentration acts as a trigger for de novo synthesis of ERES.

Passing the torch: evaluating exportability of a violence intervention program

BackgroundA violence intervention program (VIP) developed at our trauma center resulted in a reduction of injury recidivism to 4% from a historical rate of 16%. Our aim was to investigate the feasibility of exporting our program to another trauma center by examining rates of and identifying potential barriers to recruitment, enrollment, and impact. We hypothesized that our VIP is feasible at another trauma center and successfully meets needs associated with risk reduction. MethodsIn January 2010, we introduced our VIP to another trauma center. To assess exportability of our program, we used a standard model of program evaluation for VIPs promoted by the Centers for Disease Control and Prevention. Specifically, the process and impact portions of the model evaluation were performed in this comparative analysis over a 1-year period. Recruitment, enrollment (process), and success at meeting risk reduction needs (impact) were our outcomes. This included patient and case manager characteristics in addition to rates at which eligible patients were approached and enrolled. These variables were compared using the Wilcoxon rank-sum and chi-square tests. ResultsDuring the study period, 155 patients were eligible for inclusion at the exported program compared with 119 at the original VIP. Rates at which eligible patients were approached at the exported program were significantly lower than the original program (44% vs 92%, P = .04). Rates at which approached patients were enrolled were also significantly lower (21% vs 55%, P = .002). The difference was associated with the time of injury and hospital length of stay because 40% of eligible patients were missed if injury occurred during a weekend and 70% were missed if the length of stay was less than or equal to 48 hours at the exported program. A cultural match between the client and case manager was assessed by race/ethnicity and language spoken; 2 of the 3 case managers at our site are Latino and bilingual and the other is black, whereas the 1 case manager at the exported program is black and monolingual. Cultural match was 91% versus 47%, respectively (P < .05). Impact: Both programs met more than 50% of identified client needs in several categories. ConclusionsProgram exportation is based on the replication of both the program model and the program infrastructure. The data in our study support success of the program model (case management process) at our export site, but the actual program infrastructure was not successfully exported to this hospital.

Coupled transport of Arabidopsis p24 proteins at the ER–Golgi interface

p24 proteins are a family of type I membrane proteins localized to compartments of the early secretory pathway and to coat protein I (COPI)- and COPII-coated vesicles. They can be classified, by sequence homology, into four subfamilies, named p24α, p24β, p24γ, and p24δ. In contrast to animals and fungi, plants contain only members of the p24β and p24δ subfamilies. It has previously been shown that transiently expressed red fluorescent protein (RFP)–p24δ5 localizes to the endoplasmic reticulum (ER) as a consequence of highly efficient COPI-based recycling from the Golgi apparatus. Using specific antibodies, endogenous p24δ5 has now been localized to the ER and p24β2 to the Golgi apparatus in Arabidopsis root tip cells by immunogold electron microscopy. The relative contributions of the cytosolic tail and the luminal domains to p24δ5 trafficking have also been characterized. It is demonstrated that whereas the dilysine motif in the cytoplasmic tail determines the location of p24δ5 in the early secretory pathway, the luminal domain may contribute to its distribution downstream of the Golgi apparatus. By using knock-out mutants and co-immunoprecipitation experiments, it is shown that p24δ5 and p24β2 interact with each other. Finally, it is shown that p24δ5 and p24β2 exhibit coupled trafficking at the ER–Golgi interface. It is proposed that p24δ5 and p24β2 interact with each other at ER export sites for ER exit and coupled transport to the Golgi apparatus. Once in the Golgi, p24δ5 interacts very efficiently with the COPI machinery for retrograde transport back to the ER.

Nitrous acid at Concordia (inland site) and Dumont d'Urville (coastal site), East Antarctica

During the austral summer 2010/2011, nitrous acid (HONO) was investigated for the first time at Concordia (75°06′S, 123°33′E) and Dumont D'Urville (66°40′S, 140°01′E), two sites located in East Antarctica. Hereby, for the first time in Antarctica, HONO was measured by deploying a long path absorption photometer (LOPAP). At Concordia, HONO mixing ratios at 1 m above the snow surface ranged between 5 and 60 pptv from end of December 2010 to mid January 2011. Lowest levels were observed under cloudy conditions. Levels exhibit a diurnal cycle with a maximum in the morning (around 06:00) and in the evening (around 21:00). At Dumont d'Urville, background mixing ratios remained close to 2 pptv in February 2011. No clear diurnal cycles were detected at that site but several events of air masses export from inland Antarctica were encountered with enhanced HONO levels (10 pptv) at night. These first HONO data gained in East Antarctica are discussed in terms of sources and sinks along with synoptic weather conditions.

SEC23-SEC31 the Interface Plays Critical Role for Export of Procollagen from the Endoplasmic Reticulum

COPII proteins are essential for exporting most cargo molecules from the endoplasmic reticulum. The membrane-facing surface of the COPII proteins (especially SEC23-SEC24) interacts directly or indirectly with the cargo molecules destined for exit. As we characterized the SEC23A mutations at the SEC31 binding site identified from patients with cranio-lenticulo-sutural dysplasia, we discovered that the SEC23-SEC31 interface can also influence cargo selection. Remarkably, M702V SEC23A does not compromise COPII assembly, vesicle size, and packaging of cargo molecules into COPII vesicles that we have tested but induces accumulation of procollagen in the endoplasmic reticulum when expressed in normal fibroblasts. We observed that M702V SEC23A activates SAR1B GTPase more than wild-type SEC23A when SEC13-SEC31 is present, indicating that M702V SEC23A causes premature dissociation of COPII from the membrane. Our results indicate that a longer stay of COPII proteins on the membrane is required to cargo procollagen than other molecules and suggest that the SEC23-SEC31 interface plays a critical role in capturing various cargo molecules.

The ER/Golgi Interface - Is There Anything in-between?

OPINION article Front. Plant Sci., 18 April 2012Sec. Plant Cell Biology Volume 3 - 2012 | https://doi.org/10.3389/fpls.2012.00073