Chemical Characterization and Phytotoxic Effects of the Aerial Parts of Ruzigrass (Urochloa ruziziensis)

Studies of the phytotoxic effects between plants can be a crucial tool in the discovery of innovative compounds with herbicide potential. In this sense, we can highlight ruzigrass (Urochloa ruziziensis), which is traditionally used in the crop rotation system in order to reduce weed emergence. The aim of this work was to characterize the secondary metabolites of ruzigrass and to evaluate its phytotoxic effects. In total, eight compounds were isolated: friedelin, oleanolic acid, α‐amyrin, 1‐dehydrodiosgenone, sitosterol and stigmasterol glycosides, tricin and p‐coumaric acid. Phytotoxic effects of the crude methanolic extract and fractions of ruzigrass were assessed using germination rate, initial seedling growth, and biomass of Bidens pilosa, Euphorbia heterophylla and Ipomoea grandifolia. Chemometric analysis discriminated the weed species into three groups, and B. pilosa was the most affected by fractions of ruzigrass. The phytotoxic activities of 1‐dehydrodiosgenone, tricin, and p‐coumaric acid are also reported, and p‐coumaric acid and 1‐dehydrodiosgenone were active against B. pilosa.     

Exploring encapsulation strategies as a protective mechanism to avoid amensalism in mixed populations of Pseudomonas taetrolens and Lactobacillus casei

Bioprocess and Biosystems Engineering - Pseudomonas taetrolens constitutes an efficient platform for the biosynthesis of lactobionic acid, a potentially prebiotic compound. Unfortunately, an...     

Monitoring tropical forests under a functional perspective with satellite‐based vegetation optical depth

Monitoring ecosystem functions in forests is a priority in a climate change scenario, as climate‐induced events may initially alter the functions more than slow‐changing attributes, such as biomass. The ecosystem functional properties (EFPs) are quantities that characterize key ecosystem processes. They can be derived by point observations of gas and energy exchanges between the ecosystems and the atmosphere that are collected globally at FLUXNET flux tower sites and upscaled at ecosystem level. The properties here considered describe the ability of ecosystems to optimize the use of resources for carbon uptake. They represent functional forest information, are dependent on environmental drivers, linked to leaf traits and forest structure, and influenced by climate change effects. The ability of vegetation optical depth (VOD) to provide forest functional information is investigated using 2011–2014 satellite data collected by the Soil Moisture and Ocean Salinity mission and using the EFPs as reference dataset. Tropical forests in Africa and South America were analyzed, also according to ecological homogeneous units. VOD jointly with water deficit information explained 93% and 87% of the yearly variability in both flux upscaled maximum gross primary productivity and light use efficiency functional properties, in Africa and South America forests respectively. Maps of the retrieved properties evidenced changes in forest functional responses linked to anomalous climate‐induced events during the study period. The findings indicate that VOD can support the flux upscaling process in the tropical range, affected by high uncertainty, and the detection of forest anomalous functional responses. Preliminary temporal analysis of VOD and EFP signals showed fine‐grained variability in periodicity, in signal dephasing, and in the strength of the relationships. In selected drier forest types, these satellite data could also support the monitoring of functional dynamics.     

Response to lethal UVA radiation in the Antarctic bacterium Pseudomonas extremaustralis: polyhydroxybutyrate and cold adaptation as protective factors

Extremophiles - Pseudomonas extremaustralis is an Antarctic bacterium with high stress resistance, able to grow under cold conditions. It is capable to produce polyhydroxyalkanoates (PHAs) mainly...     

Viral SPP1 DNA is infectious in naturally competent Bacillus subtilis cells: inter- and intramolecular recombination pathways

A proteolyzed bacteriophage (phage) might release its DNA into the environment. Here, we define the recombination functions required to resurrect an infective lytic phage from inactive environmental viral DNA in naturally competent Bacillus subtilis cells. Using phage SPP1 DNA, a model that accounts for the obtained data is proposed (i) the DNA uptake apparatus takes up environmental SPP1 DNA, fragments it, and incorporates into the cytosol different linear single-stranded (ss) DNA molecules shorter than genome-length; (ii) the SsbA-DprA mediator loads RecA onto any fragmented linear SPP1 ssDNA, but negative modulators (RecX and RecU) promote a net RecA disassembly from these ssDNAs not homologous to the host genome; (iii) single strand annealing (SSA) proteins, DprA and RecO, anneal the SsbA- or SsbB-coated complementary strands, yielding tailed SPP1 duplex intermediates; (iv) RecA polymerized on these tailed intermediates invades a homologous region in another incomplete molecule, and in concert with RecD2 helicase, reconstitutes a complete linear phage genome with redundant regions at the ends of the molecule; and (v) DprA, RecO or viral G35P SSA, may catalyze the annealing of these terminally redundant regions, alone or with the help of an exonuclease, to produce a circular unit-length duplex viral genome ready to initiate replication.     

A large proportion of mediastinal and perirenal visceral fat of Siberian adult people is formed by UCP1 immunoreactive multilocular and paucilocular adipocytes

Journal of Physiology and Biochemistry - Many deleterious consequences for health of excessive fat accumulation are due to visceral fat. Browning of visceral fat is mainly cold dependent and has...     

Beyond the green: assessing quarry restoration success through plant and beetle communities

In assessing the effectiveness of ecological restoration actions, outcomes evaluation using a multi‐taxa approach can greatly contribute to a clearer understanding of their success/failure. Since comprehensive biodiversity assessments are rarely possible, choosing taxa groups that are indicative of the ecosystem's structural and functional recovery is of major importance. Our goal was to evaluate the success of revegetation actions performed in a Mediterranean limestone quarry, using plants and epigean beetles as indicators. We compared their abundance, diversity, and community composition between revegetated sites aged 5, 13, and 19 years and a natural reference. Total plant cover significantly increased with restoration age and quickly reached reference values. However, native woody species cover dropped in the oldest site, while non‐native species became dominant. The abundance of beetles was always lower in restoration sites when compared to the reference, increasing with age, although not significantly. The richness of both plant species and beetle families was lower in restoration sites and did not show any trend towards the reference values. Finally, using nonmetric multidimensional scaling, the composition of plant and beetle communities from restoration sites showed a clear separation from the reference. Restoration efforts have successfully modified post‐quarry sites, but considerable differences remain, probably largely related to the use of the non‐native species Pinus halepensis in restoration plans. P. halepensis high cover in restoration sites greatly affects the structure of the ecosystem, and most likely its functioning too, as well as related ecosystem services, causing divergence from the reference values and compromising restoration success.     

How to measure,report and verify soil carbon change to realize the potential of soil carbon sequestration for atmospheric greenhouse gas removal

There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international ‘4p1000’ initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long‐term experiments and space‐for‐time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.