Soil–strain compatibility: the key to effective use of arbuscular mycorrhizal inoculants?

Consistency of response to arbuscular mycorrhizal (AM) inoculation is required for efficient use of AM fungi in plant production. Here, we found that the response triggered in plants by an AM strain depends on the properties of the soil where it is introduced. Two data sets from 130 different experiments assessing the outcome of a total of 548 replicated single inoculation trials conducted either in soils with a history of (1) high input agriculture (HIA; 343 replicated trials) or (2) in more pristine soils from coffee plantations (CA; 205 replicated trials) were examined. Plant response to inoculation with different AM strains in CA soils planted with coffee was related to soil properties associated with soil types. The strains Glomus fasciculatum-like and Glomus etunicatum-like were particularly performant in soil relatively rich in nutrients and organic matter. Paraglomus occultum and Glomus mosseae-like performed best in relatively poor soils, and G. mosseae and Glomus manihotis did best in soils of medium fertility. Acaulospora scrobiculata, Diversispora spurca, G. mosseae-like, G. mosseae and P. occultum stimulated coffee growth best in Chromic, Eutric Alluvial Cambisol, G. fasciculatum-like and G. etunicatum-like in Calcaric Cambisol and G. manihotis, in Chromic, Eutric Cambisols. Acaulospora scrobiculata and Diversispora spurca strains performed best in Chromic Alisols and Rodic Ferralsols. There was no significant relationship between plant response to AM fungal strains and soil properties in the HIA soil data set, may be due to variation induced by the use of different host plant species and to modification of soil properties by a history of intensive production. Consideration of the performance of AM fungal strains in target soil environments may well be the key for efficient management of the AM symbiosis in plant production

Identification of Host Genes Involved in Geminivirus Infection Using a Reverse Genetics Approach

Geminiviruses, like all viruses, rely on the host cell machinery to establish a successful infection, but the identity and function of these required host proteins remain largely unknown. Tomato yellow leaf curl Sardinia virus (TYLCSV), a monopartite geminivirus, is one of the causal agents of the devastating Tomato yellow leaf curl disease (TYLCD). The transgenic 2IRGFP N. benthamiana plants, used in combination with Virus Induced Gene Silencing (VIGS), entail an important potential as a tool in reverse genetics studies to identify host factors involved in TYLCSV infection. Using these transgenic plants, we have made an accurate description of the evolution of TYLCSV replication in the host in both space and time. Moreover, we have determined that TYLCSV and Tobacco rattle virus (TRV) do not dramatically influence each other when co-infected in N. benthamiana, what makes the use of TRV-induced gene silencing in combination with TYLCSV for reverse genetic studies feasible. Finally, we have tested the effect of silencing candidate host genes on TYLCSV infection, identifying eighteen genes potentially involved in this process, fifteen of which had never been implicated in geminiviral infections before. Seven of the analyzed genes have a potential anti-viral effect, whereas the expression of the other eleven is required for a full infection. Interestingly, almost half of the genes altering TYLCSV infection play a role in postranslational modifications. Therefore, our results provide new insights into the molecular mechanisms underlying geminivirus infections, and at the same time reveal the 2IRGFP/VIGS system as a powerful tool for functional reverse genetics studies

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Biodiversity of Arbuscular Mycorrhizal Fungi in South America: A Review

Identification of species is crucial in understanding how diversity changes affect ecosystemic processes. Particularly, soil microbial are key factors of ecosystemic functioning .Among soil microbes, arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are worldwide distributed and form symbiotic associations with almost 80% of the vascular plants of the earth, except for one species, Geosiphon pyriformis, which associates with the cyanobacteria Nostoc. AMF comprise around 300 morphologically defined or 350–1000 molecularly defined taxa. Since AMF associate with aboveground community, their occurrence and composition can influence ecosystemic processes either through affecting plant community composition and thus its processes rates, or soil microbial communities, which are directly involved in nutrient cycling. Soil microorganisms are considered a potentially suitable target for studying regional and local effects on diversity. The symbiosis with AMF not only increases nutrient uptake by the plant of mainly phosphorus (P) and nitrogen (N) in exchange for plant-assimilated carbon (C), but also improves the tolerance of plants to various biotic and abiotic stresses such as pathogens, salinity, and drought

Organometal(loid) compounds associated with human metabolism

Ingestion expts. using gaseous samples, salvia, urine, blood, and feces were conducted to investigate human metab. of the metalloids selenium, mercury, arsenic, and bismuth. Some differences exist in the metab. of metalloids in the human body. Contrary to selenium, ingestion of arsenic and bismuth compds. increased the total amt. and speciation of these elements in urine and blood. Most of the ingested bismuth ends up in the colon, where hydride formation and methylation occurs, eventually leading to the presence of bismuthine and methylated bismuth species in blood and breath. The process of biol. element volatilization in the colon can also be demonstrated for antimony, and may be similar for mercury. In the latter case, highly neurotoxic methylated mercurials will be formed