title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=625 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: PIN1 protects auditory hair cells from senescence via autophagy link: https://peerj.com/articles/14267 last-modified: 2022-11-01 description: BackgroundAge-related hearing loss is an increasing sensorineural hearing loss. But the pathogenesis of ARHL has not been clarified. Herein, we studied the role and significance of PIN1 in regulating autophagy activity in senescence HEI-OC1cells and HCs.Methods and ResultsC57BL/6 mice and HEI-OC1 cells were contained in our research. Transfection of plasmids and juglone were used to upregulate or inhibit the PIN 1 expression. Immunofluorescence and Western blot were used to detect the expression of PIN1, LC3, p62, p21 and p16 protein levels in the hair cells of C57BL/6 mice cochleae and HEI-OC1 cells. Senescence-associated β-galactosidase (SA-β-gal) staining was used to investigate the senescent level.The results of this study showed that the level of autophagy increased in the senescent auditory hair cells. When inhibited the autophagy level with 3-MA, the senescent HEI-OC1 cells were alleviated. The autophagy activity in senescent HEI-OC1 cells also could be reduced by overexpressing PIN1 protein. On the contrary, inhibiting PIN1 could increase the autophagy level of senescent cells and cochlear hair cells.ConclusionPIN1 might regulate autophagy activity to induce the senescent of HEI-OC1cells and HCs, which will provide a theoretical support for the prevention and treatment of age-related hearing loss. creator: Zhe Lv creator: Yanzhuo Zhang creator: Huan Cao creator: Qingjuan Liu creator: Xiaojuan Feng creator: Huan Yin creator: BaoShan Wang uri: https://doi.org/10.7717/peerj.14267 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Lv et al. title: Years of sand fixation with Caragana korshinskii drive the enrichment of its rhizosphere functional microbes by accumulating soil N link: https://peerj.com/articles/14271 last-modified: 2022-11-01 description: C. korshinskii is one of the most widely-planted sand-fixing legumes in northwest China and exploring its rhizosphere microbiome is of great ecological importance. However, the effect of long-term sand fixation on the composition, diversity, and underlying functions of microbes in the C. korshinskii rhizosphere in dryland ecosystems remain unclear. Here, we performed high-throughput sequencing using a 16S rRNA (absolute quantification) and bacterial functional annotation of prokaryotic taxa (FAPROTAX) analysis and an ITS (relative quantification) and fungal functional guild (FUNGuild) analysis to investigate the C. korshinskii rhizosphere microbiome and metabolic functional groups at different sand-fixing ages (six years, CK6; twelve years, CK12; and eighteen years, CK18) and determined the physicochemical properties of the rhizosphere soil. Results showed that the key bacterial taxa of the rhizosphere were significantly more abundant in CK18 than in CK12 and CK6 at the phylum-class-genus level, and that fungal Glomeromycota was also significantly more abundant in the CK18 rhizosphere compared to CK12 and CK6. Among these bacterial taxa, the enrichment effect of key, functional, genus-level species of bacteria was the most obvious, including Rhizobium, Ensifer, Neorhizobium, Mesorhizobium, Streptomyces, Sphingomonas, and Flavobacterium, which are N-fixing and/or phosphate-solubilizing groups. The significant improvement seen in the physicochemical properties of the CK18 rhizosphere soil, including the higher total nitrogen (TN), available nitrogen (AN), pH, electrical conductivity (EC), higher N:P ratio, and lower C:N ratio, all demonstrated the relationship between the rhizosphere microbes and soil carbon (C) and nitrogen (N) cycling. A redundancy analysis (RDA) of different taxonomic levels indicated a close positive relationship between rhizosphere microbes and AN. In addition, the functional groups of the C. korshinskii rhizosphere bacteria were closely related to soil AN and were mainly composed of chemoheterotrophy and aerobic chemoheterotrophy. A Spearman correlation analysis revealed that these functional groups were mainly identified from bacterial Actinobacteria, Proteobacteria, Verrucomicrobia, Bacteroidetes, and fungal Glomeromycota. Our study provides evidence that the rhizosphere microbes of C. korshinskii are closely related to the accumulation of N in the restoration of desert ecosystems, and that the ecological functional processes they are involved in mainly involve C and N cycles, which play an important role in desertification reversal. creator: Wangsuo Liu creator: Kaiyang Qiu creator: Yingzhong Xie creator: Ruixia Wang creator: Haichao Li creator: Wenfen Meng creator: Yi Yang creator: Yeyun Huang creator: Yayuan Li creator: Yi He uri: https://doi.org/10.7717/peerj.14271 license: https://creativecommons.org/licenses/by-nc/4.0 rights: ©2022 Liu et al. title: Validation of General Anxiety Disorder (GAD-7) questionnaire in Spanish nursing students link: https://peerj.com/articles/14296 last-modified: 2022-11-01 description: BackgroundNursing students are at risk of anxiety during their university education.ObjectiveTo determine the psychometric characteristics of the General Anxiety Disorder (GAD-7) questionnaire in a population of university nursing students.MethodsA cross-sectional study was carried out with 170 students at the University of Jaen (Spain) in 2022. An online questionnaire was administered that included sociodemographic and student profile variables, the GAD-7 questionnaire, and the Goldberg anxiety subscale. An exploratory factor analysis (EFA), validation with convergence, and reliability analysis using Cronbach’s α were performed.ResultsThe EFA identified a single component that explained 63.50% of the variance. It was positively correlated with the Goldberg anxiety subscale (r = 0.653; p < 0.001). A statistically significant association was observed with academic year, gender, and having experienced an anxiety crisis (p < 0.005). Internal consistency with Cronbach’s α was 0.903.ConclusionThe GAD-7 presents appropriate psychometric characteristics for use in a university population of nursing students. It is capable of detecting symptoms and generalized anxiety disorder, making it a useful and simple tool for detecting anxiety-related problems in this population. creator: Sergio Martínez-Vázquez creator: Juan Miguel Martínez-Galiano creator: Rocío Adriana Peinado-Molina creator: Belén Gutiérrez-Sánchez creator: Antonio Hernández-Martínez uri: https://doi.org/10.7717/peerj.14296 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Martínez-Vazquez et al. title: Changing surface wax compositions and related gene expression in three cultivars of Chinese pear fruits during cold storage link: https://peerj.com/articles/14328 last-modified: 2022-11-01 description: The surface wax of fruit has a significant effect on abiotic stress and fruit quality. In this study, the composition of the waxes found on fruit surfaces and the related gene expression of three different pear cultivars (Xuehua, Yali, and Yuluxiang) were investigated during cold storage. The results showed that 35 wax compositions were found on the surfaces of the three pear cultivars, mainly including C29 alkane, three fatty acids, two esters, three aldehydes, three fatty alcohols, and three triterpenoids. The largest amount of C29 alkane, three fatty acids and two esters were found in Yuluxiang (YLX) on day 90, while aldehydes with carbons of C30 and C32 were the highest in Yali (YL). Xuehua (XH) showed the largest amount of C22 fatty alcohol on day 180 compared to YLX and YL. Larger amounts of triterpenoids were found in XH and YL when compared to YLX. The expression levels of fifteen wax related genes (LACS1, KCS2, KCS6, FDH, KCS20, GL8, CER10, CER60, LTPG1, LTP4, ABCG12, CER1L, CAC3, CAC3L, and DGAT1L) reached their peak at day 45 in YLX, compared to XH and YL, their expression levels in YLX were higher to different degrees. These results suggest that the different expression patterns of wax-related genes may be closely related to the difference in wax compositions of the surface wax of three pear cultivars. creator: Dan Li creator: Yudou Cheng creator: Zhonglin Shang creator: Junfeng Guan uri: https://doi.org/10.7717/peerj.14328 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Li et al. title: Cinnamaldehyde regulates mitochondrial quality against hydrogen peroxide induced apoptosis in mouse lung mesenchymal stem cells via the PINK1/Parkin signaling pathway link: https://peerj.com/articles/14045 last-modified: 2022-10-31 description: BackgroundIdiopathic pulmonary fibrosis (IPF) is a fatal respiratory disease without effective treatments. Mitochondrial dysfunction weakens the ability of mesenchymal stem cells (MSCs) to repair the distal lung epithelium, which is a probable pathogenesis of IPF. In previous research, we found that cinnamaldehyde (CA) can maintain the mitochondrial morphology of MSCs.MethodsThis present study evaluated the effect and mechanism of CA on murine lung MSCs using the hydrogen peroxide model. Antioxidant effects and mitochondrial function were determined using flow cytometry. The mRNA levels of mitochondrial dynamics and the expressions of autophagy-related proteins were also detected.ResultsCA can increase the levels of SOD, MMP and ATP, decrease the rate of ROS and apoptosis, and restore the mitochondrial structure. CA can also improve the mRNA expression of MFN1, MFN2, FIS1, DRP1, OPA1, and PGC-1α, increase the expression of LC3 II and p62 and promote the PINK1/Parkin signaling pathway. Our results demonstrated that CA can control mitochondrial quality and avoid apoptosis, which may be associated with the regulation of the PINK1/Parkin signaling pathway. creator: Shiwen Ke creator: Wei Zhu creator: Zhihui Lan creator: Yuanbing Zhang creator: Lisha Mo creator: Guoshuang Zhu creator: Liangji Liu uri: https://doi.org/10.7717/peerj.14045 license: https://creativecommons.org/licenses/by-nc/4.0 rights: ©2022 Ke et al. title: Spatial distribution, diversity, and taphonomy of clypeasteroid and spatangoid echinoids of the central Florida Keys link: https://peerj.com/articles/14245 last-modified: 2022-10-31 description: BackgroundIrregular echinoids are ecosystem engineers with diverse functional services. Documenting present-day distribution of those widespread organisms is important for understanding their ecological significance and enhancing our ability to interpret their rich fossil record.MethodsThis study summarizes SCUBA surveys of clypeasteroid and spatangoid echinoids conducted in 2020 and 2021 along the central part of the Florida Keys. The survey included observations on both live and dead specimens, their distribution, habitat preferences, abundance, and live-dead comparison.ResultsEchinoids were found at 17 out of 27 examined sites (63%) and occurred across a wide range of habitats including coastal seagrass meadows, subtidal sand and seagrass settings of the Hawk Channel, backreef sands, and fine muddy sands of deeper forereef habitats. The encountered species, both dead and alive, included Clypeaster rosaceus (four sites), Clypeaster subdepressus (five sites), Encope michelini (three sites), Leodia sexiesperforata (eight sites), Meoma ventricosa (nine sites), and Plagiobrissus grandis (four sites). All sites were dominated by one species, but some sites included up to five echinoid species. Live-dead fidelity was high, including a good agreement in species composition of living and dead assemblages, congruence in species rank abundance, and overlapping spatial distribution patterns. This high fidelity may either reflect long-term persistence of local echinoid populations or fragility of echinoid tests that could prevent post-mortem transport and the formation of time-averaged death assemblages. Regardless of causative factors, the live-dead comparisons suggest that irregular echinoid assemblages, from settings that are comparable to the study area, may provide a fossil record with a high spatial and compositional fidelity. The survey of live fauna is consistent with past regional surveys in terms of identity of observed species, their rank abundance, and their spatial distribution patterns. The results suggest that despite increasingly frequent hurricanes, active seasonal fisheries, massive tourism, and urban development, irregular echinoids continue to thrive across a wide range of habitats where they provide diverse ecosystem services by oxygenating sediments, recycling organic matter, supporting commensal organisms, and providing food to predators. Results reported here document the present-day status of local echinoid populations and should serve as a useful reference point for assessing future regional changes in echinoid distribution and abundance. creator: Tobias B. Grun creator: Michał Kowalewski uri: https://doi.org/10.7717/peerj.14245 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2022 Grun and Kowalewski title: Bioacoustic differentiation of calls in the chiffchaff complex link: https://peerj.com/articles/14261 last-modified: 2022-10-31 description: The chiffchaff complex is a group of common forest bird species, notorious for the number of cryptic taxa recently discovered, being a great example of speciation in action. Vocalizations have been crucial to unveil its hidden diversity. In this study we quantitatively analyze the acoustic characteristics of their calls with permutational analysis of variance, canonical variate analysis and a self-organizing map, to determine their variability and differences. We related these differences with the geographical and genetic distances between taxonomic groups, by means of Pearson correlations. We used recordings from Xeno-canto, an open database of bird vocalizations. Inter-taxa distances based on call traits were broadly consistent with geographic distances but not correlated with genetic distances. The Iberian Chiffchaff (Phylloscopus ibericus), presumably the most ancient lineage, was the most central in the variation space, while the Siberian Chiffchaff (P. collybita tristis) was the most peripheric and also very uniform, in contrast with the Canarian Chiffchaff (P. canariensis) highly variable, as expected by the “character release hypothesis” on islands. Calls proved to be an excellent tool, especially amenable for non-biased mathematical analyses which, combined with the wide availability of records in Xeno-canto, greatly facilitates the widespread use of this methodology in a wide range of species and geographical areas. creator: Maria Calviño-Cancela creator: Laura Piña creator: Julio Martín-Herrero uri: https://doi.org/10.7717/peerj.14261 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Calviño-Cancela et al. title: Physiological and ecological characteristics and reproductive responses of Phragmites australis to dry-wet conditions in inland saline marshes of Northeast China link: https://peerj.com/articles/14269 last-modified: 2022-10-31 description: Inland saline marshes in northeastern China have unique soil characteristics and population distribution features. Hydrological change is a critical environmental factor causing wetland degradation and soil salinization in this region. The growth and reproductive responses of typical wetland plants to dry-wet alternations are essential for restoring inland saline marshes. A pot experiment was conducted to study the growth and reproductive responses of Phragmites australis populations to three hydrological treatments simulating drought degradation (drought), permanent inundation restoration (flooding), and seasonal inundation restoration (dry-wet). The species showed different growth and reproductive responses to the three treatments. After 120 d, the drought conditions induced a lower biomass, root length and root surface area of P. australis, but with higher root diameter, soluble sugar, and Na+ ion contents. Flooding and alternating dry-wet treatments induced the opposite responses. Alternating dry-wet treatments can be considered a better solution to effectively conserve water and meet the water needs of P. australis in the current growing season. The biomass under the alternating wet and dry treatment was the same as that under flooding, but the number of rhizome shoots was lower. The alternating dry-wet treatments was able to recover the growth of P. australis in the current season, but the potential for asexual reproduction of the species was insufficient. creator: Cui Mingyang creator: Du Zhixin creator: Li Xiaoyu creator: Chen Junze uri: https://doi.org/10.7717/peerj.14269 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Mingyang et al. title: Nitrogen fertilization and CO2 concentration synergistically affect the growth and protein content of Agropyron mongolicum link: https://peerj.com/articles/14273 last-modified: 2022-10-31 description: BackgroundThe nitrogen (N) and protein concentrations in plant tissues exposed to elevated CO2 (eCO2) generally decline , such declines in forage grass composition are expected to have negative implications for the nutritional and economic value of grass. Plants require N for the production of a photosynthetically active canopy and storage proteins in the tissues, whose functionality will strongly influence productivity and quality. The objective of this study was to investigate whether eCO2 plus N-fertilization increases growth and N nutrition of Agropyron mongolicum, and the dependence of this improvement on the coordination between root and leaf development.MethodsWe analyzed A. mongolicum from field-grown within the open-top chambers (OTCs) facility under two atmospheric CO2 (ambient, 400 ± 20 µmol mol−1, aCO2, and elevated, 800 ± 20 µmol mol−1, eCO2) and three N-fertigation treatments (control, low N-fertigation , and high N-fertigation) for two months.ResultsElevated CO2 plus N-fertigation strongly increased shoot and root biomass, and the nitrogen and protein concentrations of A. mongolicum compared to those plants at aCO2 levels. Increased N content in leaves and reduced specific leaf area (SLA) at a high N supply could alleviate photosynthetic acclimation to eCO2 and drive the production of greater shoot biomass with the potential for higher photosynthesis, productivity, and nutritional quality. The increased root length (RL), the ratio of total aboveground N taken up per RL (TN/RL), stomatal conductance (Gs), and transpiration rate (Tr) contribute to the transpiration-driven mass flow of N, consequently increasing N uptake by roots. In addition, a smaller percentage of N remained as unassimilated nitrate (${\mathrm{NO}}_{3}^{-}$NO3−) under eCO2, indicating that assimilation of ${\mathrm{NO}}_{3}^{-}$NO3− into proteins was not inhibited by eCO2. These findings imply that grass productivity and quality will enhance under anticipated elevated CO2 concentration when effective management measures of N-fertilization are employed. creator: Aiyun Xu creator: Lihua Zhang creator: Xiaojia Wang creator: Bing Cao uri: https://doi.org/10.7717/peerj.14273 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Xu et al. title: SES1 is vital for seedling establishment and post-germination growth under high-potassium stress conditions in Arabidopsis thaliana link: https://peerj.com/articles/14282 last-modified: 2022-10-31 description: BackgroundThe potassium ion (K+) plays an important role in maintaining plant growth and development, while excess potassium in the soil can cause stress to plants. The understanding of the molecular mechanism of plant’s response to high KCl stress is still limited.MethodsAt the seed stage, wild type (WT) and SENSITIVE TO SALT1 (SES1) mutants were exposed to different concentrations of potassium treatments. Tolerance was assayed as we compared their performances under stress using seedling establishment rate and root length. Na+content, K+content, and K+/Na+ ratio were determined using a flame atomic absorption spectrometer. In addition, the expressions of KCl-responding genes and ER stress-related genes were also detected and analyzed using qRT-PCR.ResultsSES1 mutants exhibited seedling establishment defects under high potassium concentration conditions and exogenous calcium partially restored the hypersensitivity phenotype of ses1 mutants. The expression of some K+ transporter/channel genes were higher in ses1-2, and the ratio of potassium to sodium (K+/Na+) in ses1-2 roots decreased after KCl treatment compared with WT. Further analysis showed that the ER stress marker genes were dramatically induced by high K+ treatment and much higher expression levels were detected in ses1-2, indicating ses1-2 suffers a more serious ER stress than WT, and ER stress may influence the seedling establishment of ses1-2 under high KCl conditions.ConclusionThese results strongly indicate that SES1 is a potassium tolerance relevant molecule that may be related to maintaining the seedling K+/Na+ balance under high potassium conditions during seedling establishment and post-germination growth. Our results will provide a basis for further studies on the biological roles of SES1 in modulating potassium uptake, transport, and adaptation to stress conditions. creator: Peiyan Guan creator: Chen Xie creator: Dongbo Zhao creator: Liyan Wang creator: Chengchao Zheng uri: https://doi.org/10.7717/peerj.14282 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Guan et al.