Response of soil microbial community to plant composition changes in broad-leaved forests of the karst area in Mid-Subtropical China
The rapid growth and expansion ofCryptomeria japonica (Thunb. ex L. f.) D. Don in karst area strongly affects plant composition of native deciduous broad-leaved forest, which seriously threat ecosystem function and service. Given the importance of soil microorganisms in regulating nutrients cycling and plant species coexistence, understanding soil microbial attributes and their relationships with soil and vegetation features in forests harboring different C. japonica abundance will help understanding the drivers of ecosystem function changes. Here we examined the diversity and composition of soil bacterial and fungal communities and their correlations with plant diversity as well as soil physicochemical properties in karst broad-leaved forests with different relative abundances of C. japonica (i.e., a high, moderate, low and no proportion level with a stem density of 1,487, 538, 156 and 0 plant/hm2, respectively) in Mid-Subtropical China. We found that soil pH decreased while soil water content (SWC), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) tended to increase with the increase in C. japonica abundance. In contrast, soil available nitrogen (AN), available phosphorus (AP) and available potassium (AK) content declined by 26.1%∼49.3% under the high level of C. japonica abundance. A gradual decrease in relative abundance of Acidobacteria and Chloroflexi while a pronounced increase in relative abundance of Ascomycota and Basidiomycota were observed with increase of C. japonica abundance. Alternations in bacterial composition were closely related to changes in AP and AK, while the change of fungal structure was mainly related to SWC, soil organic carbon (SOC) and pH, indicating that bacterial community was sensitive to declines in soil available nutrients and fungal structure was sensitive to changes in soil physicochemical properties (i.e., pH and SWC) and organic carbon resource. Understory plants had the highest α-diversity in forest containing moderate abundance of C. japonica, which might be related to the high bacterial diversity. Our findings suggest conservation of soil bacterial and fungal taxa that are responsible for nutrients availability and carbon sequestration is of great significance for improving the resistance of natural deciduous broad-leaved forests to the rapid spread of C. japonica in karst areas. Moreover, Acidobacteria, Chloroflexi, Ascomycota and Basidiomycota are potential indicators for soil properties changes, which should be taken into consideration in karst forest managements.
Liu et al. (2022) Response of soil microbial community to plant composition changes in broad-leaved forests of the karst area in Mid-Subtropical China. PeerJ 10:e12739 https://doi.org/10.7717/peerj.12739
Growth, maturity, and diet of the pearl whipray (Fontitrygon margaritella) from the Bijagós Archipelago, Guinea-Bissau
The pearl whipray Fontitrygon margaritella (Compagno & Roberts, 1984) is a common elasmobranch in coastal western African waters. However, knowledge on their life-history and trophic ecology remains limited. Therefore, we aimed to determine the growth, maturity and diet of F. margaritella from the Bijagós Archipelago in Guinea-Bissau. Growth was modelled with: von Bertalanffy, Gompertz and logistic functions. Model selection revealed no model significantly outperformed another. The sampled age ranged from less than 1 to 7 years (1.8 ± 1.9 cm, mean ± standard deviation) and size (disc width) ranged from 12.2 to 30.6 cm (18.7 ± 5.2 cm). Size-at-maturity was estimated at 20.3 cm (95% CI [18.8–21.8 cm]) for males and 24.3 cm for females (95% CI [21.9–26.5 cm]), corresponding ages of 2.2 and 3.9 years. The diet differed significantly among young-of-the-year (YOY), juveniles and adults (p = 0.001). Diet of all life stages consisted mainly of crustaceans (27.4%, 28.5%, 33.3%) and polychaetes (12.5%, 26.7%, 20.3%), for YOY, juveniles and adults respectively. This study shows that F. margaritella is relatively fast-growing, matures early and experiences ontogenetic diet shifts. These results contribute to status assessments and conservation efforts of F. margaritella and closely related species.
Clements et al. (2022) Growth, maturity, and diet of the pearl whipray (Fontitrygon margaritella) from the Bijagós Archipelago, Guinea-Bissau. PeerJ 10:e12894 https://doi.org/10.7717/peerj.12894
Sea urchin harvest inside marine protected areas: an opportunity to investigate the effects of exploitation where trophic upgrading is achieved
Background Marine protected areas (MPAs) usually have both positive effects of protection for the fisheries’ target species and indirect negative effects for sea urchins. Moreover, often in MPAs sea urchin human harvest is restricted, but allowed. This study is aimed at estimating the effect of human harvest of the sea urchin Paracentrotus lividus within MPAs, where fish exploitation is restricted and its density is already controlled by a higher natural predation risk. The prediction we formulated was that the lowest densities of commercial sea urchins would be found where human harvest is allowed and where the harvest is restricted, compared to where the harvest is forbidden. Methods At this aim, a collaborative database gained across five MPAs in Sardinia (Western Mediterranean, Italy) and areas outside was gathered collecting sea urchin abundance and size data in a total of 106 sites at different degrees of sea urchin exploitation: no, restricted and unrestricted harvest sites (NH, RH and UH, respectively). Furthermore, as estimates made in past monitoring efforts (since 2005) were available for 75 of the sampled sites, for each of the different levels of exploitation, the rate of variation in the total sea urchin density was also estimated. Results Results have highlighted that the lowest sea urchin total and commercial density was found in RH sites, likely for the cumulative effects of human harvest and natural predation. The overall rate of change in sea urchin density over time indicates that only NH conditions promoted the increase of sea urchin abundance and that current local management of the MPAs has driven towards an important regression of populations, by allowing the harvest. Overall, results suggest that complex mechanisms, including synergistic effects between natural biotic interactions and human pressures, may occur on sea urchin populations and the assessment of MPA effects on P. lividus populations would be crucial to guide management decisions on regulating harvest permits. Overall, the need to ban sea urchin harvest in the MPAs to avoid extreme reductions is encouraged, as inside the MPAs sea urchin populations are likely under natural predation pressures for the trophic upgrading.
Ceccherelli et al. (2022) Sea urchin harvest inside marine protected areas: an opportunity to investigate the effects of exploitation where trophic upgrading is achieved. PeerJ 10:e12971 https://doi.org/10.7717/peerj.12971
A new Amazonian species of Allobates Zimmermann & Zimmermann, 1988 (Aromobatidae) with a trilled advertisement call
Background Currently, 58 species are assigned to the genus Allobates, with 70% of its diversity described just in the last two decades, with many additional species likely unnamed. The continuous description of these new species represents a fundamental step for resolving the taxonomy and ensuring the future conservation of the genus. Methods Using molecular, acoustic, and morphological evidences, we describe a new species of Allobates from Teles Pires River region, southern Amazonia, and provide accounts on the population of A. tapajos found sympatrically with the new species. Results The new species is distinguished from its congeners by the coloration of thighs, venter, dorsum, and dark lateral stripe. It has four types of calls, with advertisement calls formed by relatively long trills with a mean duration of 2.29 s ± 0.65, mean of 39.93 notes ± 11.18 emitted at a mean rate of 17.49 ± 0.68 notes per second, and mean dominant frequency of 5,717 Hz ± 220.81. The genetic distance between the new species and its congeners in a fragment of the 16S mitochondrial fragment ranged between 13.2% (A. carajas) to 21.3% (A. niputidea). The sympatric Allobates population fits its morphology and acoustic with the nominal A. tapajos, but presents a relatively high genetic distance of nearly 6.5%, raising questions on the current taxonomy of this species.
Silva et al. (2022) A new Amazonian species of Allobates Zimmermann & Zimmermann, 1988 (Aromobatidae) with a trilled advertisement call. PeerJ 10:e13026 https://doi.org/10.7717/peerj.13026
Perception, knowledge, and attitude of medical doctors in Saudi Arabia about the role of physiotherapists in vestibular rehabilitation: a cross-sectional survey
Objectives There is compelling scientific evidence about the role of physiotherapists in vestibular rehabilitation. However, patients with vestibular-associated dizziness and balance disturbances are seldom referred to physiotherapists in Saudi Arabia. Therefore, this study aims to achieve insight into perceptions, knowledge, attitudes, and referral practices among Saudi Arabian medical doctors relating to the role of physiotherapists in vestibular rehabilitation. Methods A sample of 381 medical doctors practicing in Saudi Arabia participated in this nationwide cross-sectional study. The sample was obtained from 226 hospitals across 13 provinces of Saudi Arabia by stratified sampling method. The 23-item questionnaire developed by a team of experts was emailed to medical doctors practicing in various hospitals across Saudi Arabia. Results Out of 1,231 medical doctors invited, 381 medical doctors responded, giving a response rate of 30.9%. One hundred ninety-three (50.6%) medical doctors reported managing patients with vestibular rehabilitation. The most preferred specialist for managing patients with vestibular disorders was an Ear Nose Throat (ENT) specialist (n = 173, 89.6%). Related Sample Cochran’s Q test showed statistically significant difference between preferred specialist for managing patients with vestibular disorders (ENT specialists, physiotherapists, nurses, occupational therapists and audiologists) (χ2(4) = 482.476, p = 0.001). Out of 193 medical doctors, 153 (79.2%) reported no role of the physiotherapist in vestibular rehabilitation. One hundred forty-five (75.1%) of medical doctors reported that they were not aware of the role of physiotherapists in vestibular rehabilitation. Only 27 (15.5%) medical doctors reported referring patients with vestibular disorders to physiotherapists. Conclusion The study reports that physiotherapy services are underutilized in vestibular rehabilitation due to limited referral from Saudi Arabian medical doctors. Therefore, there is a need to increase the awareness among Saudi Arabian doctors about the physiotherapist’s role in vestibular rehabilitation.
Alyahya et al. (2022) Perception, knowledge, and attitude of medical doctors in Saudi Arabia about the role of physiotherapists in vestibular rehabilitation: a cross-sectional survey. PeerJ 10:e13035 https://doi.org/10.7717/peerj.13035
Loss of gut microbial diversity in the cultured, agastric fish, Mexican pike silverside (Chirostoma estor: Atherinopsidae)
Teleost fish are the most diverse group of extant vertebrates and have varied digestive anatomical structures and strategies, suggesting they also possess an array of different host-microbiota interactions. Differences in fish gut microbiota have been shown to affect host development, the process of gut colonization, and the outcomes of gene-environment or immune system-microbiota interactions. There is generally a lack of studies on the digestive mechanisms and microbiota of agastric short-intestine fish however, meaning that we do not understand how changes in gut microbial diversity might influence the health of these types of fish. To help fill these gaps in knowledge, we decided to study the Mexican pike silverside (Chirostoma estor) which has a simplified alimentary canal (agastric, short-intestine, 0.7 gut relative length) to observe the diversity and metabolic potential of its intestinal microbiota. We characterized gut microbial populations using high-throughput sequencing of the V3 region in bacterial 16S rRNA genes while searching for population shifts resulting associated with fish development in different environments and cultivation methods. Microbiota samples were taken from the digesta, anterior and posterior intestine (the three different intestinal components) of fish that grew wild in a lake, that were cultivated in indoor tanks, or that were raised in outdoor ponds. Gut microbial diversity was significantly higher in wild fish than in cultivated fish, suggesting a loss of diversity when fish are raised in controlled environments. The most abundant phyla observed in these experiments were Firmicutes and Proteobacteria, particularly of the genera Mycoplasma, Staphylococcus, Spiroplasma, and Aeromonas. Of the 14,161 OTUs observed in this experiment, 133 were found in all groups, and 17 of these, belonging to Acinetobacter, Aeromonas, Pseudomonas, and Spiroplasma genera, were found in all samples suggesting the existence of a core C. estor microbiome. Functional metagenomic prediction of bacterial ecological functions using PICRUSt2 suggested that different intestinal components select for functionally distinct microbial populations with variation in pathways related to the metabolism of amino acids, vitamins, cofactors, and energy. Our results provide, for the first time, information on the bacterial populations present in an agastric, short-gut teleost with commercial potential and show that controlled cultivation of this fish reduces the diversity of its intestinal microbiota.
Amillano-Cisneros et al. (2022) Loss of gut microbial diversity in the cultured, agastric fish, Mexican pike silverside (Chirostoma estor: Atherinopsidae). PeerJ 10:e13052 https://doi.org/10.7717/peerj.13052
Hydrogen sulphide alleviates Fusarium Head Blight in wheat seedlings
Hydrogen sulphide (H2S), a crucial gas signal molecule, has been reported to be involved in various processes related to development and adversity responses in plants. However, the effects and regulatory mechanism of H2S in controlling Fusarium head blight (FHB) in wheat have not been clarified. In this study, we first reported that H2S released by low concentrations of sodium hydrosulphide (NaHS) could significantly alleviate the FHB symptoms caused by Fusarium graminearum (F. graminearum) in wheat. We also used coleoptile inoculation to investigate the related physiological and molecular mechanism. The results revealed that FHB resistance was strongly enhanced by the H2S released by NaHS, and 0.3 mM was confirmed as the optimal concentration. H2S treatment dramatically reduced the levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA) while enhancing the activities of antioxidant enzymes. Meanwhile, the relative expressions levels of defence-related genes, including PR1.1, PR2, PR3, and PR4, were all dramatically upregulated. Our results also showed that H2S was toxic to F. graminearum by inhibiting mycelial growth and spore germination. Taken together, the findings demonstrated the potential value of H2S in mitigating the adverse effects induced by F. graminearum and advanced the current knowledge regarding the molecular mechanisms in wheat.
Yao et al. (2022) Hydrogen sulphide alleviates Fusarium Head Blight in wheat seedlings. PeerJ 10:e13078 https://doi.org/10.7717/peerj.13078
Growth regulators promote soybean productivity: a review
Soybean [Glycine max (L.) Merrill] is a predominant edible plant and a major supply of plant protein worldwide. Global demand for soybean keeps increasing as its seeds provide essential proteins, oil, and nutraceuticals. In a quest to meet heightened demands for soybean, it has become essential to introduce agro-technical methods that promote adaptability to complex environments, improve soybean resistance to abiotic stress , and increase productivity. Plant growth regulators are mainly exploited to achieve this due to their crucial roles in plant growth and development. Increasing research suggests the influence of plant growth regulators on soybean growth and development, yield, quality, and abiotic stress responses. In an attempt to expatiate on the topic, current knowledge, and possible applications of plant growth regulators that improve growth and yield have been reviewed and discussed. Notably, the application of plant growth regulators in their appropriate concentrations at suitable growth periods relieves abiotic stress thereby increasing the yield and yield components of soybean. Moreover, the regulation effects of different growth regulators on the morphology, physiology, and yield quality of soybean are discoursed in detail.
Amoanimaa-Dede et al. (2022) Growth regulators promote soybean productivity: a review. PeerJ 10:e12556 https://doi.org/10.7717/peerj.12556
A combined association of serum uric acid, alanine aminotransferase and waist circumference with non-alcoholic fatty liver disease: a community-based study
Background Increasing evidence has supported that serum uric acid (SUA), alanine aminotransferase (ALT) and waist circumference (WC) are associated with the occurrence of non-alcoholic fatty liver disease (NAFLD). However, the combined role of these factors in early screening of NAFLD has not been investigated. We aimed to de lineate this role in a community-based population. Methods Binary logistic regression was used to explore the correlations of SUA, ALT and WC with NAFLD risk. The goodness of fit and discriminative ability of the model were evaluated by the Hosmer-Lemeshow test and area under the receiver operating characteristic curve (AUROC), respectively. Results Logistic regression analysis indicated that elevated SUA (adjusted odds ratio (OR) = 2.44, 95% confidence interval (CI) [1.76–3.38]), ALT (adjusted OR = 4.98, 95% CI [3.41–7.27]) and WC (adjusted OR = 3.22, 95% CI [2.01–5.16]) were facilitating factors for incident NAFLD after fully adjusted for related confounders. In addition, the risk of NAFLD followed linear trend s with increasing levels of these three indicators (all Ptrend < 0.001). The risk assessment model consisting of SUA, ALT, WC and demographics showed useful discrimination by AUROC being 0.825 (95% CI [0.811–0.838]) and good performance of calibration (P = 0.561). Conclusions SUA, ALT and WC were all associated with NAFLD, independent of known risk factors. The simple model composed of these indicators showed good performance in the Chinese population, which may be applicable for appraisal of NAFLD risk in primary healthcare.
Wang et al. (2022) A combined association of serum uric acid, alanine aminotransferase and waist circumference with non-alcoholic fatty liver disease: a community-based study. PeerJ 10:e13022 https://doi.org/10.7717/peerj.13022
Morphological description and molecular identification of Myxobolus dajiangensis n. sp. (Myxozoa: Myxobolidae) from the gill of Cyprinus carpio in southwest China
Background Myxosporean diversity is a hot topic since they are difficult to accurately identify and classify. Many Myxobolus parasites have been named as Myxobolus koi because of their similar morphological features with the species originally reported. However, the distinctions in fine morphological features, host specificity, and molecular data have given rise to the attention of researchers. Methods The classical morphometric and histological methods were used to describe the Myxobolus dajiangensis n. sp. in morphology. The common techniques in modern molecular biology and the methods of phylogenetic analyses were combined to identify the species. Results Plasmodia of interlamellar-vascular type were found in the vascular network of gill lamellae. Mature myxospores of M. dajiangensis n. sp. were elongated and pyriform from the frontal view. The myxospores were 14.8 ± 0.4 (13.9–15.6) µm in length, 8.0 ± 0.5 (7.2–9.1) µm in width, and 5.5 µm in thickness. The two polar capsules were pyriform and slightly different in length. The length of the larger polar capsules was 8.0 ± 0.4 (7.1–8.8) µm, and it was 7.4 ± 0.4 (6.1–8.0) µm for the smaller ones. The width of both polar capsules was 2.5 ± 0.2 (2.0–3.2) µm. The polar filaments within the polar capsules were each coiled nine to 11 turns. Comparative analysis of both the morphological and molecular data between the present speices and other similar species revealed that the present species is a novel species, Myxobolus dajiangensis n. sp. Also, M. koi (FJ710800) was misidentified and the congener with M. dajiangensis n. sp., depending on the secondary structures of SSU rRNA and phylogenetic analysis. Moreover, the cryptic species existed in the M. koi parasites.
Wang et al. (2022) Morphological description and molecular identification of Myxobolus dajiangensis n. sp. (Myxozoa: Myxobolidae) from the gill of Cyprinus carpio in southwest China. PeerJ 10:e13023 https://doi.org/10.7717/peerj.13023