Main conclusionRhizobacteria and silicon fertilization synergism suppress leaf and panicle Blast, and mitigates biotic stress in rice plants.AbstractAssociation of bioagents and silicon is synergistic for mitigating leaf and panicle blast and low phosphorus (P) levels in upland rice, under greenhouse conditions. This study aimed to evaluate the potential of the bioagents and silicon interaction on blast disease severity suppression in upland rice plants, under field low P conditions. The experiment was conducted during two growing seasons (E1 and E2), in randomized block design with four replications, and consisted of five treatments, combining a mix of three rhizobacteria, BRM 32114 and BRM62523 (Serratia marcescens), and BRM32110 (Bacillus toyonensis), and three application methods (seed treatment, drenching, spraying). Calcium and magnesium silicate (2 t/ha) was applied over a low soil P, 30 days before sowing. Leaf blast (LBS) and panicle blast (PBS), area under the disease progress curve (AUDPC), activity of enzymes related to oxidative stress, pathogenesis-related (PR), biochemical indicators such as hydrogen peroxide, chlorophyll a and b, carotenoids, and grain yield (GY), were assessed. Bioagents and silicon suppressed LBS by 77.93 and PBS by 62.37%, reduced AUDPC by 77.3 (LBS) and 60.6% (PBS). The yield in E1 was 25% higher than in E2. The treatments statistically differ only in E2, the yield with bioagents and silicon (2435.72 kg ha-1) was 71.95% higher compared to the absolute control. All enzymatic activities related to oxidative stress and PR proteins were modulated by bioagents and silicon association. The association of rhizobacteria and silicon exhibited a synergistic effect, and represents a bioprotective combination to reduce the effects of different stresses and indirectly reduces the use of chemical inputs.

Monitoring groundwater levels and soil moisture content (SMC) is crucial for managing water resources and assessing risks, but can be challenging, especially over large acreages. Recent advances in geophysical methods provide new opportunities for accurate groundwater assessment. Seismic wave speed data, sensitive to changes in pore water pressure, can be used in a passive monitoring approach, while electrical conductivity data can be used for monitoring SMC. Combining seismic and electromagnetic induction (EMI)-based monitoring techniques enhances our understanding of groundwater dynamics. Seismic methods enable wide spatial coverage with moderate depth resolution, whereas EMI offers high-resolution, rapid data acquisition, particularly effective for shallow subsurface monitoring. Integrating these approaches can leverage the strengths of each, yielding comprehensive, high-resolution insights into dynamic subsurface hydrological processes. Integrating these approaches allows for improved groundwater monitoring, aiding in better understanding and managing droughts in regions like the Netherlands.

Plants respond to complex blends of above- and below-ground volatile organic compounds (VOCs) emitted by neighboring plants. These responses often involve priming (i.e., preparation) or induction (i.e., increase) of defenses by receiver plants upon exposure to VOCs released by herbivore-damaged neighboring emitters. However, recent work has shown that induction of VOC emissions by herbivory is modulated by abiotic factors, potentially affecting plant-plant signaling. We tested the effect of soil salinization on the induction of VOC emissions in wild cotton (Gossypium hirsutum) due to leaf damage and its consequences for the induction of defenses in neighboring plants. To this end, we performed a greenhouse factorial experiment where emitter plants were subjected to augmented soil salinity (vs. ambient salinity) and within each group emitter plants were subsequently exposed to simulated caterpillar damage (mechanical leaf damage treated with Spodoptera frugiperda oral secretion) or no damage (control). After 48 h of exposure, we collected VOCs released by emitter plants and then damaged the receivers and collected their leaves to measure levels of chemical defenses (terpenoid aldehydes of known insecticidal effects). We found an interaction between leaf damage and salinization for two groups of VOCs released by emitters (sesquiterpenes and other aromatic compounds), whereby damaged receivers had higher emissions than control plants under ambient but not salinized soil conditions. We also found that, upon being damaged, receiver plants exposed to damaged emitters exhibited a significantly higher concentration of heliocides (but not gossypol) than control plants. However, salinization did not alter this VOC exposure effect on receiver induced responses to damage. Overall, we show that exposure to induced VOC emissions from damaged plants magnifies the induction of chemical defenses due to leaf damage in neighboring individuals and that this is not contingent on the level of soil salinity despite the latter's effect on VOC induction.

Douglas-fir (Pseudotsuga menziesii var. menziesii) is an important species in the Pacific Northwest including California forests. Due to the increasing need for reforestation in this region after widespread disturbances related to changes in climate (i.e., drought, megafires, beetle mortality), it is necessary to examine the factors that contribute to performance and survival of planted seedlings in reforestation projects. While most conifer planting in northern California is done in spring, fall planting is also an alternative practice used. With the recent increase in demand of seedlings for reforestation projects beyond which the current infrastructure is capable of, particularly in spring, expanding the fall planting season has potential to mitigate this and constraints to the spring labor force. Here, we studied the first-year performance of both spring and fall planted Douglas-fir seedlings for different seed sources and nursery cultural timings at a single site in northern California. We found that the fall planting can be successful in October or November, while planting earlier requires immediately favorable temperature and soil moisture conditions. Later sowing and blackout regimes also resulted in increases in height growth and bud development while also reducing damage due to spring freezes. For spring planting, early sow and blackout resulted in earlier bud break, while later sow, blackout, and lift dates benefited the first-year growth of height and diameter.

Since 1989, investigations into viral ecology have revealed how bacteriophages can influence microbial dynamics within ecosystems at global scales. Most of the information we know about temperate phages, which can integrate themselves into the host genome and remain dormant via a process called lysogeny, has come from research in aquatic ecosystems. Soil environments remain under-studied, and more research is necessary to fully understand the range of impacts phage infections have on the soil bacteria they infect. The aims of this study were to compare the efficacy of different prophage-inducing agents and to elucidate potential temporal trends in lysogeny within a soil bacterial community. In addition to mitomycin C and acyl-homoserine lactones, our results indicated that halosulfuron methyl herbicides may also be potent inducing agents. In optimizing chemical induction assays, we determined that taking steps to reduce background virus particles and starve cells was critical in obtaining consistent results. A clear seasonal trend in inducible lysogeny was observed in an Appalachian oak-hickory forest soil. The average monthly air temperature was negatively correlated with inducible fraction and burst size, supporting the idea that lysogeny provides a mechanism for phage persistence when temperatures are low and host metabolism is slower. Furthermore, the inducible fraction was negatively correlated with both soil bacterial and soil viral abundance, supporting the idea that lysogeny provides a mechanism for temperate phage persistence when host density is lower. The present study is the first of its kind to reveal clear seasonal trends in inducible lysogeny in any soil.IMPORTANCELysogeny is a relationship in which certain viruses that infect bacteria (phages) may exist within their bacterial host cell as a segment of nucleic acid. In this state, the phage genome is protected from environmental damage and retains the potential to generate progeny particles in the future. It is thought that lysogeny provides a mechanism for long-term persistence for phages when host density is low or hosts are starved-two conditions likely to be found in soils. In the present study, we provide the first known evidence for a seasonal trend in lysogeny in a forest soil. Based on clear relationships observed between lysogeny, temperature, and soil microbial abundance, we find support for previous hypotheses regarding the factors governing lysogeny. Lysogeny is a relationship in which certain viruses that infect bacteria (phages) may exist within their bacterial host cell as a segment of nucleic acid. In this state, the phage genome is protected from environmental damage and retains the potential to generate progeny particles in the future. It is thought that lysogeny provides a mechanism for long-term persistence for phages when host density is low or hosts are starved-two conditions likely to be found in soils. In the present study, we provide the first known evidence for a seasonal trend in lysogeny in a forest soil. Based on clear relationships observed between lysogeny, temperature, and soil microbial abundance, we find support for previous hypotheses regarding the factors governing lysogeny.

BACKGROUND Informal electronic waste (e -waste) reprocessing in Nigeria is reportedly substantial in Africa, putting the growing exposed population at high risk of metal toxicity. This study aimed to investigate the existence of chromosomal aberration in the growing e -waste exposed populations in Nigeria, using induction of micronuclei (MN) expression in peripheral blood as an indicator. METHODS In this cross-sectional study, 632 consenting participants were recruited from South-West Nigeria, consisting of 381 e -waste workers (EWW), 120 environmental e -waste exposed participants (EEP) and 131 age -matched unexposed participants (UP) serving as controls. A validated structured questionnaire was used to assess exposure pattern while frequency of micronucleated polychromatic erythrocytes (MNPCE)/1000PCE in peripheral blood film was determined by modified micronucleus assay. RESULTS A duration of exposure of >= 5 years and exposure frequency >= 6 hours/day; 6 days/week (9360 hours in any 5year duration) was observed in both EWW and EEP. Routes of exposure observed in EWW entailed eyes, oral cavity, nasal cavity and skin. EWW that used personal protective equipment (PPE) while working was barely 10.24% while non -PPE users constituted the majority (89.76%) of the studied population. Frequency of MNPCE)/1000PCE in EWW (22.70 +/- 0.15) was significantly higher than in EEP (4.17 +/- 0.28), which in turn was significantly higher than the lowest frequency (0.99 +/- 0.76) observed in UP (p<0.001). CONCLUSION The observed exposure pattern and the comparatively higher MN induction in the e -waste populations may suggest risk of significant cytogenetic damage and aberrant chromosomal changes associated with occupational e -waste reprocessing in Nigeria.

Anthropogenic climate change threatens water storage and supply in the periglacial critical zone. Rock glaciers are widely distributed alpine aquifers with slower response to temperature increases, that provide the summer water flow of many alpine streams. Knowing the extent and makeup of rock glaciers is necessary to evaluate their potential for water supply. We used non-invasive methods, integrating geological, geomorphological, meteoro-logical, and geophysical information to characterize the internal structure and hydrology of the Upper Camp Bird rock glacier (UCBRG) located on level 3 of Camp Bird Mine in Ouray, Colorado, and assessed the applicability of two electromagnetic induction systems in this highly heterogeneous landform with a history of anthropogenic activity. The time-domain (G-TEMTM) system achieved deep subsurface penetration (similar to 100 m) and realistic modeling of the internal structure of the UCBRG: a shell of volcanic rock fragments (< 3 m thick; 1-100 Ohm-m), a meltwater component (10(2)-10(3) Ohm-m), located between 50 and 100 m near the toe (subpermafrost flow), and 1-30 m in the soundings farthest from the toe (suprapermafrost flow within the active layer), and a frozen component (permafrost 50-80 m thick; 10(3)-10(6) Ohm-m). The frequency-domain system, however, was highly susceptible to local environmental conditions, including anthropogenic objects (i.e., mine carts, lamp posts, tunnel tracks, etc.) and was unable to resolve UCBRG's internal makeup. The non-invasive methodology and general conceptual framework presented here can be used to characterize other alpine aquifers, contributing to the quantification of global water resources, and highlighting the importance of preserving rock glaciers as storage for critical water supply in the future.

The Galileo mission to Jupiter discovered magnetic signatures associated with hidden subsurface oceans at the moons Europa and Callisto using the phenomenon of magnetic induction. These induced magnetic fields originate from electrically conductive layers within the moons and are driven by Jupiter's strong time-varying magnetic field. The ice giants and their moons are also ideal laboratories for magnetic induction studies. Both Uranus and Neptune have a strongly tilted magnetic axis with respect to their spin axis, creating a dynamic and strongly variable magnetic field environment at the orbits of their major moons. Although Voyager 2 visited the ice giants in the 1980s, it did not pass close enough to any of the moons to detect magnetic induction signatures. However, Voyager 2 revealed that some of these moons exhibit surface features that hint at recent geologically activity, possibly associated with subsurface oceans. Future missions to the ice giants may therefore be capable of discovering subsurface oceans, thereby adding to the family of known ocean worlds in our Solar System. Here, we assess magnetic induction as a technique for investigating subsurface oceans within the major moons of Uranus. Furthermore, we establish the ability to distinguish induction responses created by different interior characteristics that tie into the induction response: ocean thickness, conductivity and depth, and ionospheric conductance. The results reported here demonstrate the possibility of single-pass ocean detection and constrained characterization within the moons of Miranda, Ariel, and Umbriel, and provide guidance for magnetometer selection and trajectory design for future missions to Uranus.

The tilt between Neptune's magnetic and rotational axes, along with Triton's orbital obliquity, causes a strong time variability of the moon's local electromagnetic environment. To constrain Triton's interaction with the ambient magnetospheric plasma, we apply a hybrid (kinetic ions, fluid electrons) model including the moon's ionosphere and induced field. To represent the extremes in the changes to the local electromagnetic field over a synodic rotation, we consider two orientations between the ambient magnetic field and flow velocity. For each, we first investigate the (analytical) magnetic signatures associated with the superposition of Triton's induced field and the magnetospheric field in the absence of any plasma interaction effects. To constrain the effect of Triton's ionosphere on the currents, we model the interaction between the ionospheric and magnetospheric plasma in isolation from the moon's inductive response, before combining these effects to investigate the complex scenario of plasma interaction and induction. Finally, we explore the sensitivity of the plasma interaction to changes in the ambient plasma density and the strength of Triton's inductive response. Despite plasma interaction signatures that dominate the plasma perturbations far from the moon (beyond similar to 3 Triton radii), we illustrate that the induced field is clearly discernible within similar to 3 Triton radii, regardless of the moon's location within Neptune's magnetosphere. We find that the orientation of the magnetospheric field and velocity vectors strongly affects Triton's plasma interaction; at times, resembling those of Jupiter's or Saturn's moons, while at others, revealing unprecedented signatures that are likely unique to moons of the ice giants.

The distribution of shallow frozen ground is paramount to research in cold regions, and is subject to temporal and spatial changes influenced by climate, landscape disturbance and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically lacks the resolution to characterise finer-scale processes and phenomena, which are better captured by integrated surface geophysical methods. Here, we demonstrate the use of electrical resistivity imaging (ERI), electromagnetic induction (EMI), ground penetrating radar (GPR) and infrared imaging over multiple summer field seasons around the highly dynamic Twelvemile Lake, Yukon Flats, central Alaska, USA. Twelvemile Lake has generally receded in the past 30yr, allowing permafrost aggradation in the receded margins, resulting in a mosaic of transient frozen ground adjacent to thick, older permafrost outside the original lakebed. ERI and EMI best evaluated the thickness of shallow, thin permafrost aggradation, which was not clear from frost probing or GPR surveys. GPR most precisely estimated the depth of the active layer, which forward electrical resistivity modelling indicated to be a difficult target for electrical methods, but could be more tractable in time-lapse mode. Infrared imaging of freshly dug soil pit walls captured active-layer thermal gradients at unprecedented resolution, which may be useful in calibrating emerging numerical models. GPR and EMI were able to cover landscape scales (several kilometres) efficiently, and new analysis software showcased here yields calibrated EMI data that reveal the complicated distribution of shallow permafrost in a transitional landscape. Copyright (c) 2016 John Wiley & Sons, Ltd.