The Ruminant sorting mechanism protects teeth from abrasives.

Dental wear due to ingestion of dust and grit has deleterious consequences. Herbivores that could not wash their food hence had to evolve particularly durable teeth, in parallel to the evolution of dental chewing surface complexity to increase chewing efficacy. The rumen sorting mechanism increases chewing efficacy beyond that reached by any other mammal and has been hypothesized to also offer an internal washing mechanism, which would be an outstanding example of an additional advantage by a physiological adaptation, but in vivo evidence is lacking so far. Here, we investigated four cannulated, live cows that received a diet to which sand was added. Silica in swallowed food and feces reflected experimental dietary sand contamination, whereas the regurgitate submitted to rumination remained close to the silica levels of the basal food. This helps explain how ruminants are able to tolerate high levels of dust or grit in their diet, with less high-crowned teeth than nonruminants in the same habitat. Palaeo-reconstructions based on dental morphology and dental wear traces need to take the ruminants' wear-protection mechanism into account. The inadvertent advantage likely contributed to the ruminants' current success in terms of species diversity.

Swimming through sand: using accelerometers to observe the cryptic, pre-emergence life-stage of sea turtle hatchlings.

Animals that hatch within a subterranean nest, such as turtle hatchlings, expend some of their limited energy reserves digging out through sand or soil to reach the surface. In sea turtles, this emergence process can take the hatchlings 3-7 days. However, we have a poor understanding of this process as it is difficult to observe what is occurring underground. Here, we utilize a novel method to characterize digging-out behaviour: affixing an accelerometer directly to newly hatched green turtles (Chelonia mydas) to record movement until nest emergence. Our data revealed that buried hatchlings maintained a head-up orientation but did not move in the expected left and right swaying motion associated with alternating limb crawling. Rather, they moved using dorsal-ventral heaving and pitching as if swimming vertically through the sand to the surface. Movement activity was irregular and brief, interspersed by many short periods of inactivity, mostly lasting less than 10 min. The first 24 h of head-up activity displayed no diel patterns, but the last 24 h prior to emergence involved more intense movement during night-time hours compared with daytime hours. Thus, our results add valuable new insight, and in some cases change previous assumptions, regarding the digging behaviours during the egg-to-emergence life stage in sea turtles.

Accounting for the microbial assembly of each process in wastewater treatment plants (WWTPs): study of four WWTPs receiving similar influent streams.

We evaluated a unique model in which four full-scale wastewater treatment plants (WWTPs) with the same treatment schematic and fed with similar influent wastewater were tracked over an 8-month period to determine whether the community assembly would differ in the activated sludge (AS) and sand filtration (SF) stages. For each WWTP, AS and SF achieved an average of 1-log10 (90%) and <0.02-log10 (5%) reduction of total cells, respectively. Despite the removal of cells, both AS and SF had a higher alpha and beta diversity compared to the influent microbial community. Using the Sloan neutral model, it was observed that AS and SF were individually dominated by different assembly processes. Specifically, microorganisms from influent to AS were predominantly determined by the selective niche process for all WWTPs, while the microbial community in the SF was relatively favored by a stochastic, random migration process, except two WWTPs. AS also contributed more to the final effluent microbial community compared with the SF. Given that each WWTP operates the AS independently and that there is a niche selection process driven mainly by the chemical oxygen demand concentration, operational taxonomic units unique to each of the WWTPs were also identified. The findings from this study indicate that each WWTP has its distinct microbial signature and could be used for source-tracking purposes.IMPORTANCEThis study provided a novel concept that microorganisms follow a niche assembly in the activated sludge (AS) tank and that the AS contributed more than the sand filtration process toward the final microbial signature that is unique to each treatment plant. This observation highlights the importance of understanding the microbial community selected by the AS stage, which could contribute toward source-tracking the effluent from different wastewater treatment plants.

Pleistocene diversification of unifoliolate-leaved Lupinus (Leguminosae: Papilionoideae) in Florida.

The importance and prevalence of recent ice-age and post-glacial speciation and species diversification during the Pleistocene across many organismal groups and physiographic settings are well established. However, the extent to which Pleistocene diversification can be attributed to climatic oscillations and their effects on distribution ranges and population structure remains debatable. In this study, we use morphologic, geographic and genetic (RADseq) data to document Pleistocene speciation and intra-specific diversification of the unifoliolate-leaved clade of Florida Lupinus, a small group of species largely restricted to inland and coastal sand ridges across the Florida peninsula and panhandle. Phylogenetic and demographic analyses alongside morphological and geographic evidence suggest that recent speciation and intra-specific divergence within this clade were driven by a combination of non-adaptive allopatric divergence caused by edaphic niche conservatism and opportunities presented by the emergence of new post-glacial sand ridge habitats. These results highlight the central importance of even modest geographic isolation and short periods of allopatric divergence following range expansion in the emergence of new taxa and add to the growing evidence that Pleistocene climatic oscillations may contribute to rapid diversification in a myriad of physiographic settings. Furthermore, our results shed new light on long-standing taxonomic debate surrounding the number of species in the Florida unifoliate Lupinus clade providing support for recognition of five species and a set of intra-specific variants. The important conservation implications for the narrowly restricted, highly endangered species Lupinus aridorum, which we show to be genetically distinct from its sister species Lupinus westianus, are discussed.

Coupled hydraulics and carbon economy underlie age-related growth decline and revitalisation of sand-fixing shrubs after crown removal.

Crown removal revitalises sand-fixing shrubs that show declining vigour with age in drought-prone environments; however, the underlying mechanisms are poorly understood. Here, we addressed this knowledge gap by comparing the growth performance, xylem hydraulics and plant carbon economy across different plant ages (10, 21 and 33 years) and treatments (control and crown removal) using a representative sand-fixing shrub (Caragana microphylla Lam.) in northern China. We found that growth decline with plant age was accompanied by simultaneous decreases in soil moisture, plant hydraulic efficiency and photosynthetic capacity, suggesting that these interconnected changes in plant water relations and carbon economy were responsible for this decline. Following crown removal, quick resprouting, involving remobilisation of root nonstructural carbohydrate reserves, contributed to the reconstruction of an efficient hydraulic system and improved plant carbon status, but this became less effective in older shrubs. These age-dependent effects of carbon economy and hydraulics on plant growth vigour provide a mechanistic explanation for the age-related decline and revitalisation of sand-fixing shrubs. This understanding is crucial for the development of suitable management strategies for shrub plantations constructed with species having the resprouting ability and contributes to the sustainability of ecological restoration projects in water-limited sandy lands.

Climate warming and sea turtle sex ratios across the globe.

Climate warming and the feminization of populations due to temperature-dependent sex determination may threaten sea turtles with extinction. To identify sites of heightened risk, we examined sex ratio data and patterns of climate change over multiple decades for 64 nesting sites spread across the globe. Over the last 62 years the mean change in air temperature was 0.85°C per century (SD = 0.65°C, range = -0.53 to +2.5°C, n = 64 nesting sites). Temperatures increased at 40 of the 64 study sites. Female-skewed hatchling or juvenile sex ratios occurred at 57 of the 64 sites, with skews >90% female at 17 sites. We did not uncover a relationship between the extent of warming and sex ratio (r62 = -0.03, p = .802, n = 64 nesting sites). Hence, our results suggest that female-hatchling sex ratio skews are not simply a consequence of recent warming but have likely persisted at some sites for many decades. So other factors aside from recent warming must drive these variations in sex ratios across nesting sites, such as variations in nesting behaviour (e.g. nest depth), substrate (e.g. sand albedo), shading available and rainfall patterns. While overall across sites recent warming is not linked to hatchling sex ratio, at some sites there is both is a high female skew and high warming, such as Raine Island (Australia; 99% female green turtles; 1.27°C warming per century), nesting beaches in Cyprus (97.1% female green turtles; 1.68°C warming per century) and in the Dutch Caribbean (St Eustatius; 91.5% female leatherback turtles; 1.15°C warming per century). These may be among the first sites where management intervention is needed to increase male production. Continued monitoring of sand temperatures and sex ratios are recommended to help identify when high incubation temperatures threaten population viability.

Antlion larvae localize long distant preys by a mechanism based on time difference.

Pit building antlions Euroleon nostras have been submitted to artificial cues in order to delineate their faculty to localize a prey. Series of propagating pulses in sand have been created from an extended source made of 10 piezoelectric transducers equally spaced on a line and located at a large distance from the pit. The envelope of each pulse encompasses six oscillations at a carrier frequency of 1250 Hz and up to eight oscillations at 1666 Hz. In one set of experiments, the first wave front is followed by similar wave fronts and the antlions respond to the cue by throwing sand in the opposite direction of the wave front propagation direction. In another set of experiments, the first wave front is randomly spatially structured while the propagation of the wave fronts inside the envelope of the pulse are not. In that case, the antlions respond less to the cue by throwing sand, and when they do, their sand throwing is more randomly distributed in direction. The finding shows that the localization of vibration signal by antlions are based on the equivalent for hearing animals of interaural time difference in which the onset has more significance than the interaural phase difference.

Benchmarking the Humidity-Dependent Mechanical Response of (Nano)fibrillated Cellulose and Dissolved Polysaccharides as Sustainable Sand Amendments.

Soil quality is one of the main limiting factor in the development of the food sector in arid areas, mainly due to its poor mechanics and lack of water retention. Soil's organic carbon is nearly absent in arid soils, though it is important for water and nutrient transport, to soil mechanics, to prevent erosion, and as a long-term carbon sink. In this study, we evaluate the potential benefits that are brought to inert sand by the incorporation of a range of, mainly, cellulosic networks in their polymeric or structured (fiber) forms, analogously to those found in healthy soils. We explore the impact of a wide range of nonfood polysaccharide-based amendments, including pulp fibers, nanocellulose, cellulose derivatives, and other readily available polysaccharide structures derived from arthropods (chitosan) or fruit peels (pectin) residues. A practical methodology is presented to form sand-polymer composites, which are evaluated for their soil mechanics as a function of humidity and the dynamics of their response to water. The mechanics are correlated to the network of polymers formed within the pores of the sandy soil, as observed by electron microscopy. The response to water is correlated to both the features of the network and the individual polysaccharides' physicochemical features. We expect this work to provide a rapid and reproducible methodology to benchmark sustainable organic amendments for arid soils.

Aquibaculum arenosum gen. nov., sp. nov., a novel member of the family Rhodovibrionaceae, isolated from sea sand.

A Gram-negative, non-motile, and creamy-white coloured bacterium, designated CAU 1616T, was isolated from sea sand collected at Ayajin Beach, Goseong-gun, Republic of Korea. The bacterium was found to grow optimally at 37 °C, pH 8.0-8.5, and with 1-5 % (w/v) NaCl. Phylogenetic analyses based on the 16S rRNA gene sequences placed strain CAU 1616T within the order Rhodospirillales. The highest 16S rRNA gene sequence similarity was to Fodinicurvata fenggangensis YIM D812T (94.1 %), Fodinicurvata sediminis YIM D82T (93.7 %), Fodinicurvata halophila BA45ALT (93.6 %) and Algihabitans albus HHTR 118T (92.3 %). Comparing strain CAU 1616T with closely related species (Fodinicurvata fenggangensis YIM D812T and Fodinicurvata sediminis YIM D82T), the average nucleotide identity based on blast+ values were 69.7-69.8 %, the average amino acid identity values were 61.3-61.4 %, and the digital DNA-DNA hybridization values were 18.4-18.5 %. The assembled draft genome of strain CAU 1616T had 29 contigs with an N50 value of 385.8 kbp, a total length of 3 490 371 bp, and a DNA G+C content of 65.1 mol%. The predominant cellular fatty acids were C18 : 1 2-OH, C19 : 0 cyclo ω8c, and summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c). The major respiratory quinone was Q-10. Based on phenotypic, phylogenetic, and chemotaxonomic evidence, strain CAU 1616T represents a novel genus in the family Rhodovibrionaceae, for which the name Aquibaculum arenosum gen. nov., sp. nov. is proposed. The type strain is CAU 1616T (=KCTC 82428T=MCCC 1K06089T).

Glycomyces niveus sp. nov., a novel actinomycete isolated from sandy soil.

A novel mycelium-forming actinomycete, designated strain NEAU-S30T, was isolated from the sandy soil of a sea beach in Shouguang city, Shandong province, PR China. The strain developed long chains of non-motile cylindrical spores with smooth surfaces on aerial mycelia. The results of a polyphasic taxonomic study indicated that NEAU-S30T represented a member of the genus Glycomyces. The results of 16S rRNA gene sequence analysis indicated that NEAU-S30T was closely related to 'Glycomycesluteolus' (98.97 % sequence similarity), Glycomycesalgeriensis (98.90 %), 'Glycomyces tritici' (98.83 %) and Glycomyces lechevalierae (98.76 %). The average nucleotide identity (ANI) values between NEAU-S30T and 'G. luteolus' NEAU-A15, G. algeriensis DSM 44727T, 'G. tritici' NEAU-C2 and G. lechevalierae DSM 44724T were 87.77, 87.53, 87.41 and 87.80 %, respectively. The digital DNA G+C content of the genomic DNA was 70.5 %. The whole-cell sugars contained ribose and xylose. The predominant menaquinones were MK-10(H2), MK-10(H4) and MK-10(H6). The predominant fatty acids were anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C15 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified glycolipid. On the basis of the results of comparative analysis of genotypic, phenotypic and chemotaxonomic data, the novel actinomycete strain NEAU-S30T (=JCM 33975T=CGMCC 4.7890T) represents the type strain of a novel species within the genus Glycomyces, for which the name Glycomyces niveus sp. nov. is proposed.

Phenylobacterium montanum sp. nov., an oligotrophic, slightly acidophilic mesophile isolated from sandy soil.

A bacterial strain, designated S6T, was isolated from the sandy soil on a rocky mountain in South China. Cells of S6T were Gram-stain-negative, aerobic, non-spore-forming, non-motile and non-prosthecae-producing. 16S rRNA gene sequence analysis revealed the highest similarities to 12 uncultured bacteria, followed by Phenylobacterium sp. B6.10-61 (97.14 %). The closest related validly published strains are Caulobacter henricii ATCC 15253T (96.15 %), Phenylobacterium conjunctum FWC 21T (96.08 %) and Caulobacter mirabilis FWC 38T (96.08 %). Phylogenetic analysis based on 16S rRNA gene, genome and proteome sequences demonstrated that S6T formed a separated lineage in the genus Phenylobacterium. Strain S6T contained Q-10 (97.5 %) as the major ubiquinone and C18 : 1 ω7c and C16 : 0 as the major fatty acids. The polar lipid profile consisted of phosphatidylglycerol, an unknown phosphoglycolipid and three unknown glycolipids. The assembled genome comprises a chromosome with a length of 5.5 Mb and a plasmid of 96 014 bp. The G+C content was 67.6 mol%. The morphological, physiological, chemotaxonomic and phylogenetic analyses clearly distinguished this strain from its closest phylogenetic neighbours. Thus it is proposed that strain S6T represents a novel species in the genus Phenylobacterium, for which the name Phenylobacterium montanum sp. nov. is proposed. The type strain is S6T (=NBRC 115419T=GCMCC 1.18594T).

Taklimakanibacter deserti gen. nov., sp. nov. and Taklimakanibacter lacteus sp. nov., isolated from desert soil.

Two Gram-stain-negative, aerobic, milk-white coloured, non-motile, short rod-shaped bacteria, designated as strains SYSU D60010T and SYSU D60012T, were isolated from sand samples collected from the Taklimakan Desert of Xinjiang Province in China. Both strains were positive for oxidase, catalase and nitrate reduction, but negative for amylase, H2S production, hydrolysis of gelatin and cellulase. Strains SYSU D60010T and SYSU D60012T grew well at 28 °C, at pH 7 and had the same NaCl tolerance range of 0-1 % (w/v). The major fatty acids (>5 %) of strains SYSU D60010T and SYSU D60012T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), iso-C19 : 0 cyclo ω8c, C16 : 0 and iso-C18 : 1 2-OH. Q-10 was the only respiratory ubiquinone. Strains SYSU D60010T and SYSU D60012T showed high 16S rRNA gene sequence similarities to Aestuariivirga litoralis SYSU M10001T (94.2 and 94.1 %), Rhodoligotrophos jinshengii BUT-3T (92.0 and 91.9 %) and Rhodoligotrophos appendicifer 120-1T (91.8 and 91.7 %), and the genomes were 7.4 and 5.8 Mbp in size with DNA G+C contents of 62.8 and 63.0 mol%, respectively. Phylogenetic, phenotypic and chemotaxonomic characteristics indicated that these two strains represent a novel genus and two novel species within the family Aestuariivirgaceae. We propose the name Taklimakanibacter deserti gen. nov., sp. nov. for strain SYSU D60010T, representing the type strain of this species (=KCTC 52783T =NBRC 113344T) and Taklimakanibacter lacteus gen. nov., sp. nov. for strain SYSU D60012T, representing the type strain of this species (=KCTC 52785T=NBRC 113128T).

Deinococcus arenicola sp. nov., a novel radiation-resistant bacterium isolated from sandy soil in Antarctica.

A Gram-stain-positive, aerobic, non-mobile and spherical strain, designated ZS9-10T, belonging to the genus Deinococcus was isolated from soil sampled at the Chinese Zhong Shan Station, Antarctica. Growth was observed in the presence of 0-4 % (w/v) NaCl, at pH 7.0-8.0 and at 4-25 °C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZS9-10T formed a lineage in the genus Deinococcus. It exhibited highest sequence similarity (97.4 %) to Deinococcus marmoris DSM 12784T. The major phospholipids of ZS9-10T were unidentified phosphoglycolipid, unidentified glycolipids and unidentified lipids. The major fatty acids were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C16 : 0 and C16 : 1 ω7c. MK-8 was the predominant respiratory quinone. The digital DNA-DNA hybridization and average nucleotide identity values between strain ZS9-10T and its close relative D. marmoris DSM 12784T were 27.4 and 83.9 %, respectively. Based on phenotypic, phylogenetic and genotypic data, a novel species, named Deinococcus arenicola sp. nov., is proposed. The type strain iis ZS9-10T (=CCTCC AB 2019392T=KCTC43192T).

Knowledge and regulation on fungal contamination of sand and water: Progress report and perspectives.

Fungal flora in coastal/inland beach sand and recreational water is a neglected field of study, despite its potential impact on human health. A joint International Society for Human and Animal Mycology/European Confederation for Medical Mycology (ISHAM/ECMM) working group was formed in 2019 with the task to set up a vast international initiative aimed at studying the fungal contamination of beaches and bathing waters. Here we review the importance of the topic, and list the main results and achievements from 12 scientific publications. Fungal contamination exists at different levels, and the genera most frequently found were Aspergillus spp., Candida spp., Fusarium spp., and Cryptococcus spp., both in sand and in water. A site-blind median was found to be 89 colony-forming units of fungi per gram of sand in coastal/inland freshwaters. This threshold has been used for the sand quality criterion of the blue flag in Portugal. Additionally, our data were considered pivotal and therefore used for the first inclusion of fungi as a biological taxon of interest in water quality and sand monitoring recommendations of the World Health Organization's new guidelines on recreational water quality (Vol.1-Chap7). The findings of the consortium also suggest how environmental conditions (climate, salinity, soil pH, nitrogen, etc.) influence microbial communities in different regions, and that yeast species like Candida glabrata, Clavispora lusitaniae, and Meyerozyma guilliermondii have been identified as potential fungal indicators of fecal contamination. Climate change and natural disasters may affect fungal populations in different environments, and because this is still a field of study under exploration, we also propose to depict the future challenges of research and unmet needs.

Nutrient supplementation-induced metabolic profile changes and early appearance of free N-glycans in nutrient deficient tomato plants revealed by mass spectrometry.

Inorganic fertilizers are routinely used in large scale crop production for the supplementation of nitrogen, phosphorus, and potassium in nutrient poor soil. To explore metabolic changes in tomato plants grown on humic sand under different nutritional conditions, matrix-assisted laser desorption ionization (MALDI) mass spectrometry was utilized for the analysis of xylem sap. Variations in the abundances of metabolites and oligosaccharides, including free N-glycans (FNGs), were determined. Statistical analysis of the sample-related peaks revealed significant differences in the abundance ratios of multiple metabolites, including oligosaccharides, between the control plants, grown with no fertilizers, and plants raised under "ideal" and "nitrogen deficient" nutritional conditions, i.e., under the three treatment types. Among the 36 spectral features tentatively identified as oligosaccharides, the potential molecular structures for 18 species were predicted based on their accurate masses and isotope distribution patterns. To find the spectral features that account for most of the differences between the spectra corresponding to the three different treatments, multivariate statistical analysis was carried out by orthogonal partial least squares-discriminant analysis (OPLS-DA). They included both FNGs and non-FNG compounds that can be considered as early indicators of nutrient deficiency. Our results reveal that the potential nutrient deficiency indicators can be expanded to other metabolites beyond FNGs. The m/z values for 20 spectral features with the highest variable influence on projection (VIP) scores were ranked in the order of their influence on the statistical model.

Changes in Microbial Composition During the Succession of Biological Soil Crusts in Alpine Hulun Buir Sandy Land, China.

Biological soil crusts (biocrusts) are considered "desert ecosystem engineers" because they play a vital role in the restoration and stability maintenance of deserts, including those cold sandy land ecosystems at high latitudes, which are especially understudied. Microorganisms participate in the formation and succession of biocrusts, contributing to soil properties' improvement and the stability of soil aggregates, and thus vegetation development. Accordingly, understanding the composition and successional characteristics of microorganisms is a prerequisite for analyzing the ecological functions of biocrusts and related applications. Here, the Hulun Buir Sandy Land region in northeastern China-lying at the highest latitude of any sandy land in the country-was selected for study. Through a field investigation and next-generation sequencing (Illumina MiSeq PE300 Platform), our goal was to assess the shifts in diversity and community composition of soil bacteria and fungi across different stages during the succession of biocrusts in this region, and to uncover the main factors involved in shaping their soil microbial community. The results revealed that the nutrient enrichment capacity of biocrusts for available nitrogen, total nitrogen, total phosphorus, total content of water-soluble salt, available potassium, soil organic matter, and available phosphorus was progressively enhanced by the succession of cyanobacterial crusts to lichen crusts and then to moss crusts. In tandem, soil bacterial diversity increased as biocrust succession proceeded but fungal diversity decreased. A total of 32 bacterial phyla and 11 fungal phyla were identified, these also known to occur in other desert ecosystems. Among those taxa, the relative abundance of Proteobacteria and Cyanobacteria significantly increased and decreased, respectively, along the cyanobacterial crust-lichen-moss crust successional gradient. However, for Actinobacteria, Chloroflexi, and Acidobacteria their changed relative abundance was significantly hump-shaped, increasing in the shift from cyanobacterial crust to lichen crust, and then decreasing as lichen crust shifted to moss crust. In this process, the improved soil properties effectively enhanced soil bacterial and fungal community composition. Altogether, these findings broaden our understanding about how soil microbial properties can change during the succession of biocrusts in high-latitude, cold sandy land ecosystems.

Co-inoculation of rhizobia and AMF improves growth, nutrient uptake, and cadmium resistance of black locust grown in sand culture.

Rhizobia and arbuscular mycorrhizal fungi (AMF) are symbiotic microorganisms important for plants grown in nutrient-deficient and heavy metal-contaminated soils. However, it remains unclear how plants respond to the coupled stress by heavy metal and nitrogen (N) deficiency under co-inoculation. Here, we investigated the synergistic effect of Mesorhizobium huakuii QD9 and Funneliformis mosseae on the response of black locust (Robinia pseudoacacia L.) grown in sand culture to cadmium (Cd) under N deficiency conditions. The results showed that single inoculation of AMF improved the growth and Cd resistance of black locust, co-inoculation improved the most. Compared to non-inoculated controls, co-inoculation mediated higher biomass and antioxidant enzyme activity, reduced oxidative stress, and promoted nodulation, mycorrhizal colonization, photosynthetic capacity, and N, P, Fe and Mg acquisition when exposed to Cd. This increase was significantly higher under N deficiency compared to N sufficiency. In addition, the uptake of Cd by co-inoculated black locust roots increased, but Cd translocation to the above-ground decreased under both N deficiency and sufficiency. Thus, in the tripartite symbiotic system, not merely metabolic processes but also Cd uptake increased under N deficiency. However, enhanced Cd detoxification in the roots and reduced allocation to the shoot likely prevent Cd toxicity and rather stimulated growth under these conditions.

Drivers of flower visit and resource sharing between the honeybee and native bees in Neotropical coastal sand dunes.

The honeybee (Apis mellifera) is one of the most important pollinator species because it can gather resources from a vast variety of plant species, including both natives and introduced, across its geographical distribution. Although A. mellifera interacts with a large diversity of plants and shares resources with other pollinators, there are some plant species with which it interacts more frequently than others. Here, we evaluated the plant traits (i.e., plant length, abundance of bloomed individuals, number of open flowers, and stamen length) that would affect the honeybee visit frequencies to the flowers in a coastal environment in the Gulf of Mexico. Moreover, we evaluated which native bee species (and their body size) overlap floral resource with A. mellifera. We registered 998 plant-bee interactions between 35 plant species and 47 bee species. We observed that plant species with low height and with high abundances of bloomed individuals are positively related to a high frequency of visits by A. mellifera. Moreover, we found that A. mellifera tends to share a higher number of plant species with other bee species with a similar or smaller body size than with bigger species, which makes them a competitor for the resource with honeybees. Our results highlight that the impacts of A. mellifera on plants and native bees could be anticipated based on its individual's characteristics (i.e., plant height and abundance of bloomed individuals) and body size, respectively.

Effects of sand substrate removal on the intestinal antioxidant and metabolism in Marsupenaeus japonicus.

M. japonicus is an important specie for factory farming, and factory farming requires an environment with sand at the bottom of the pond. However, the physiological responses as well as survival in the process of factory farming without laying sand are currently unknown. In the present study, we explored the effect of sand substrate removal on the intestinal histomorphology, antioxidant enzyme activity, and metabolic profile of M. japonicus. Our results indicate a gradual increase in the mortality rate of kuruma shrimp in ponds lacking sand substrate. The intestinal mucosa exhibited necrosis and the presence of vacuoles, with their number gradually increasing over time. The intestinal villi showed significant erosion, accompanied by a decrease in intestinal superoxide dismutase (SOD) activity and catalase (CAT) activity, and consistent with an upregulation in the expression of apoptosis-related genes such as caspase-3, indicating an adaptive response to the adverse environmental conditions. Additionally, the metabolomic analysis revealed that most significantly differential metabolites were linked to amino acid and lipid metabolism. These findings enhance our understanding of the sand substrate removal on the intestinal health of kuruma shrimp, which provides a basis for the factory farming.

Molecular Structure and Conformation of Biodegradable Water-Soluble Polymers Control Adsorption and Transport in Model Soil Mineral Systems.

Water-soluble polymers (WSPs) are used in diverse applications, including agricultural formulations, that can result in the release of WSPs to soils. WSP biodegradability in soils is desirable to prevent long-term accumulation and potential associated adverse effects. In this work, we assessed adsorption of five candidate biodegradable WSPs with varying chemistry, charge, and polarity characteristics (i.e., dextran, diethylaminoethyl dextran, carboxymethyl dextran, polyethylene glycol monomethyl ether, and poly-l-lysine) and of one nonbiodegradable WSP (poly(acrylic acid)) to sand and iron oxide-coated sand particles that represent important soil minerals. Combined adsorption studies using solution-depletion measurements, direct surface adsorption techniques, and column transport experiments over varying solution pH and ionic strengths revealed electrostatics dominating interactions of charged WSPs with the sorbents as well as WSP conformations and packing densities in the adsorbed states. Hydrogen bonding controls adsorption of noncharged WSPs. Under transport in columns, WSP adsorption exhibited fast and slow kinetic adsorption regimes with time scales of minutes to hours. Slow adsorption kinetics in soil may lead to enhanced transport but also shorter lifetimes of biodegradable WSPs, assuming more rapid biodegradation when dissolved than adsorbed. This work establishes a basis for understanding the coupled adsorption and biodegradation dynamics of biodegradable WSPs in agricultural soils.