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Although slope aspect determines the amount of solar irradiation, with implications on the functioning of forest ecosystems, little is known yet about how this affects the aboveground deadwood decomposition dynamics. Therefore, we set up a climosequence case study to evaluate the impact of slope exposure (north- vs. south-facing sites) on the physico-chemical and microbiological properties of Picea abies coarse woody debris (CWD) at different stages of natural decay (decay classes, DCls 1–5) in an Italian Alpine setting. Variations in bacterial, fungal and archaeal abundances were assessed by real-time PCR in the extra- and intracellular DNA fractions (eDNA vs. iDNA) of the total deadwood DNA pool. Physico-chemical wood properties (macro- and micronutrients; lignin and cellulose content; 3D structure via X-ray microtomography) were also performed along with the determination of key enzymatic activities involved in the main nutrient cycles. Overall, higher microbial abundances were registered in Picea abies CWD samples at the cooler, more acidic and moister north-facing site, which are favourable conditions especially for fungal wood decomposers. This thermal signal (N > S) was more evident for the advanced decay stages (DCls 4 and 5), being wood pH the most determinant factor for discriminating between both slopes. We also found that the impact of exposure was enzyme-specific and strongly dependent on the decay class, except for those enzymes involved in the P cycle. In addition, the eDNA/iDNA ratio provided a simple yet powerful index of microbial activity in terms of exposure, with lower values at the north-facing slope indicative of a higher microbial activity. This is in line with the more pronounced physical wood damage detected at this slope by the X-ray microtomography. A higher microbial activity at the cooler north-facing site rather seems surprising – a circumstance that probably is not due to temperature itself but due to increased moisture availability at this slope. [ABSTRACT FROM AUTHOR]

The article discusses the Renaissance fresco painting "Battle of Marciano," by Giorgio Vasari, particularly considering the painting's military iconography. It is noted that only wealthy people were likely to see the painting and that many men in this class had some degree of military education and, it is argued, that the painting was influenced by prevailing military ideologies and values of that time. Pikes and their appearance in the painting is considered as are the placement of the horsemen and of a figure called by the author the "inconsistent knight."

Maillard compounds were synthesized from D‐glucose and glycine to mimic the separation of particles during a volcanic eruption so that the role of quartz and volcanic ash, fractionated into silt‐ and sand‐size particles, could be tested under sterile conditions. The obtained polymers were separated into two fractions of 1000–8000 and >8000 Daltons. The results evidence the formation of humus‐like polymers from simple compounds and show the importance of substrate mineralogy. Specifically, a) humic‐like polymers can form in the absence of microbial life, b) the role of particle size is important, c) mineral substrates enhance their yields, d) the polymers on volcanic ash and quartz show differences, e) their structure changes with time, f) at the end of the experiments there is an increase of unsaturation while the aliphaticity decreases, and g) the yields of the compounds of 1000–8000 Daltons decrease with time unlike those >8000. [ABSTRACT FROM AUTHOR]

This study reports on the formation of Maillard compounds (humic-like substances called "melanoidins") from D-glucose and L-tyrosine in the presence of volcanic ash and pure quartz. It was demonstrated that the synthesis occurred not only under non-sterile, but also under sterile conditions, and under moisture and temperature stress. The temperature remained for 30 days at 70°C for 63% of the time. The non-sterile environment with a contact time of at least 30 days was the most favorable condition for the synthesis. In sterile environment, only low molecular weight polymers were formed, while in non-sterile systems high molecular weight substances were synthesized. The presence and the nature of mineral substrates appeared important even if not essential for the formation of humic-like substances. In fact, these substances were also formed by the reaction of the precursors alone. [ABSTRACT FROM AUTHOR]

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Arbuscular mycorrhizal fungi (AMF) have gained remarkable importance, having been proved to alleviate drought stress-induced damage in wheat due to their ability to ameliorate plant water use efficiency and antioxidant enzyme activity. However, despite the current relevance of the topic, the molecular and physiological processes at the base of this symbiosis never consider the single cultivar affinity to mycorrhization as an influencing factor for the metabolic response in the AMF-colonized plant. In the present study, the mycorrhizal affinity of two durum wheat species (T. turgidum subsp. durum (Desf.)) varieties, Iride and Ramirez, were investigated. Successively, an untargeted metabolomics approach has been used to study the fungal contribution to mitigating water deficit in both varieties. Iride and Ramirez exhibited a high and low level of mycorrhizal symbiosis, respectively; resulting in a more remarkable alteration of metabolic pathways in the most colonised variety under water deficit conditions. However, the analysis highlighted the contribution of AMF to mitigating water deficiency in both varieties, resulting in the up- and down-regulation of many amino acids, alkaloids, phenylpropanoids, lipids, and hormones., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Environmental DNA is made-up of intracellular (iDNA) and extracellular (eDNA) pools. In soils, eDNA can be present up to 40% and could distort the assessment of living microorganisms. Distribution of microbial community is inconsistent among different size-aggregates, and the persistence and turnover of eDNA are thus uneven. Uneven persistence and distribution of eDNA could lead to heterogeneity in community analysis biases that arise due to eDNA sequences at micro-scale distribution. Here, we investigated the diversity and structure of eDNA and iDNA bacterial communities in bulk soil and different size-aggregates. Significant differences were observed between eDNA and iDNA bacterial diversity and composition. Changes in community composition are more important than the amount of eDNA to assess the biases caused by eDNA in community analysis. Furthermore, variations were also observed in aggregates-levels for eDNA and iDNA community which indicates that colonization pattern of iDNA community and protection of eDNA through absorbance on particle surface within soil-matrix is heterogeneous. Our work provides empirical evidence that eDNA presence could mask the detection of aggregates-level spatial dynamics in soil microbial community and have potential to qualitatively baffle observed live effects of given treatment by adequately muting the actual response dynamics of the soil microbiome., (© The Author(s) 2021. Published by Oxford University Press on behalf of FEMS. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The relevance of extracellular DNA (eDNA) in the soil ecosystem is becoming more and more evident to the scientific community by the progressive discovery of functions accompanying to natural gene transformation. However, despite the increased number of published articles dedicated to eDNA in soil, so far only few are focused on its single stranded form (eDNAss). The present paper is the first to investigate the quantitative relevance of eDNAss in the total soil eDNA pool, discriminating between its linear (eDNAssl) and circular (eDNAssc) forms and the respective weakly (wa) and tightly (ta) adsorbed fractions. The results showed the prevalence of eDNAss and its linear form in both the total soil eDNA pool and its wa and ta fractions. Both of the eDNAss fractions (linear and circular) were characterized by small fragments., Competing Interests: The authors have declared that no competing interests exist.

Due to their sensitivity to changing environmental conditions sub- and alpine soils are often monitored in the context of climate change, usually, however, neglecting slope exposure. Therefore, we set up a climosequence-approach to study the effect of exposure and, in general, climate, on the microbial biomass and microbial diversity and activity, comprising five pairs of north (N)- and south (S)-facing sites along an altitudinal gradient ranging from 1200 to 2400m a.s.l. in the Italian Alps (Trentino Alto Adige, Italy). Soil physico-chemical properties were related to microbiological properties (microbial biomass: double strand DNA yield vs. substrate-induced respiration; diversity of bacterial, fungal and archaeal communities: genetic fingerprinting DGGE vs. real-time PCR; microbial activity: basal respiration vs. multiple hydrolytic enzyme assays) to monitor shifts in the diversity and activity of microbial communities as a function of slope exposure and to evaluate the most determinant chemical parameters shaping the soil microbiota. The exposure-effect on several hydrolytic key-enzymes was enzyme-specific: e.g. acid phosphomonoesterase potential activity was more pronounced at the N-facing slope while the activities of alkaline phosphomonoesterase, pyrophosphate-phosphodiesterase and arylsulfatase were higher at the S-facing slope. Furthermore, this exposure-effect was domain-specific: bacteria (S>N, altitude-independent); fungi (N~S); and archaea (N>S; altitude-dependent). Additionally, the abiotic parameters shaping the community composition were in general depending on soil depth. Our multidisciplinary approach allowed us to survey the exposure and altitudinal effects on soil physico-chemical and microbiological properties and thus unravel the complex multiple edaphic factor-effects on soil microbiota in mountain ecosystems., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Lactuca sativa L. ssp. acephala L., cv. Batavia red Mohican plants were cultivated under intensive conventional, organic and biodynamic farming and were analyzed for their polyphenol content and antiradical activity in order to demonstrate the influence of farming on yield, polyphenol content and antiradical activity., Results: The yield of plants from conventional farming was the highest (2.89 kg m⁻²), while polyphenol content, measured by spectrophotometry, of these plants was lower at P < 0.05 (1.36 mg g⁻¹) than the content of plants from organic and biodynamic farming (1.74 and 1.85 mg g⁻¹, respectively). The antiradical activity, measured by DPPH · assay, was positively correlated to flavonoid and hydroxycinnamic acid contents., Conclusion: Flavonoid, hydroxycinnamic acid and anthocyan patterns were not affected by the type of cultivation, while quantitative differences were demonstrated and some differences were found between conventional farming and organic or biodynamic farming. The yield of conventionally grown salads was the highest., (Copyright © 2011 Society of Chemical Industry.)

Antiradical activity and total polyphenol and flavonoid contents of modern and old varieties of durum (9 varieties) and soft (17 varieties) wheat grains, sampled over two years (summer 2007 and 2008) in the same site, were determined in order to point out differences among varieties and between old and modern varieties. Nine compounds were identified by means of HPLC/MS, and their amount was determined. No correlation was found between antiradical activity and polyphenol or flavonoid contents. The temperature conditions in the 30 days before harvesting were the principal factor which differentiated the quantitative profile of polyphenols and the antiradical activity of the seeds (p < 0.001): high temperatures cause a drop in polyphenol content.