Physiological and ecological characteristics and reproductive responses of Phragmites australis to dry-wet conditions in inland saline marshes of Northeast China
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.
Mingyang et al. (2022) Physiological and ecological characteristics and reproductive responses of Phragmites australis to dry-wet conditions in inland saline marshes of Northeast China. PeerJ 10:e14269 https://doi.org/10.7717/peerj.14269
Nitrogen fertilization and CO2 concentration synergistically affect the growth and protein content of Agropyron mongolicum
Background The 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. Methods We 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. Results Elevated 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 ( ${\mathrm{NO}}_{3}^{-}$ NO 3 − ) under eCO2, indicating that assimilation of ${\mathrm{NO}}_{3}^{-}$ NO 3 − 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.
Xu et al. (2022) Nitrogen fertilization and CO2 concentration synergistically affect the growth and protein content of Agropyron mongolicum. PeerJ 10:e14273 https://doi.org/10.7717/peerj.14273
SES1 is vital for seedling establishment and post-germination growth under high-potassium stress conditions in Arabidopsis thaliana
Background The 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. Methods At 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. Results SES1 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. Conclusion These 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.
Guan et al. (2022) SES1 is vital for seedling establishment and post-germination growth under high-potassium stress conditions in Arabidopsis thaliana. PeerJ 10:e14282 https://doi.org/10.7717/peerj.14282
A Python script to design primers for overlap extension PCR to ligate two DNA fragments
Ligating two or more DNA fragments is a regular operation for the subcloning and the engineering of vectors. The overlap extension PCR serves as a straightforward method to solve this issue. However, it takes a relatively long time to design the appropriate overlapping primers and the primers for the full-length sequence, and there has not been a professional offline software for such kind of primer design. Here, we propose a Python script to search, calculate and sort thousands of combinations of primers for users according to the predefined parameters. The results of script running and experimental validation show that this script is capable of generating the optimal pairs of primers based on the proper melting temperatures and lengths of the primers, which facilitates gene modification in research.
Hu et al. (2022) A Python script to design primers for overlap extension PCR to ligate two DNA fragments. PeerJ 10:e14283 https://doi.org/10.7717/peerj.14283
The complete chloroplast genome sequences of three Broussonetia species and comparative analysis within the Moraceae
Background Species of Broussonetia (family Moraceae) are commonly used to make textiles and high-grade paper. The distribution of Broussonetia papyrifera L. is considered to be related to the spread and location of humans. The complete chloroplast (cp) genomes of B. papyrifera, Broussonetia kazinoki Sieb., and Broussonetia kaempferi Sieb. were analyzed to better understand the status and evolutionary biology of the genus Broussonetia. Methods The cp genomes were assembled and characterized using SOAPdenovo2 and DOGMA. Phylogenetic and molecular dating analysis were performed using the concatenated nucleotide sequences of 35 species in the Moraceae family and were based on 66 protein-coding genes (PCGs). An analysis of the sequence divergence (pi) of each PCG among the 35 cp genomes was conducted using DnaSP v6. Codon usage indices were calculated using the CodonW program. Results All three cp genomes had the typical land plant quadripartite structure, ranging in size from 160,239 bp to 160,841 bp. The ribosomal protein L22 gene (RPL22) was either incomplete or missing in all three Broussonetia species. Phylogenetic analysis revealed two clades. Clade 1 included Morus and Artocarpus, whereas clade 2 included the other seven genera. Malaisia scandens Lour. was clustered within the genus Broussonetia. The differentiation of Broussonetia was estimated to have taken place 26 million years ago. The PCGs’ pi values ranged from 0.0005 to 0.0419, indicating small differences within the Moraceae family. The distribution of most of the genes in the effective number of codons plot (ENc-plot) fell on or near the trend line; the slopes of the trend line of neutrality plots were within the range of 0.0363–0.171. These results will facilitate the identification, taxonomy, and utilization of the Broussonetia species and further the evolutionary studies of the Moraceae family.
Yang et al. (2022) The complete chloroplast genome sequences of three Broussonetia species and comparative analysis within the Moraceae. PeerJ 10:e14293 https://doi.org/10.7717/peerj.14293
Study on eye movement characteristics and intervention of basketball shooting skill
Background The shooting aiming point is very important in basketball because it may affect the field goal percentage (FG%). The purpose of this study was to explore the influence of shooting aiming point practice on FG% and to search for new training methods for shooting improvement in basketball. Methods A total of 24 expert basketball players and 24 amateur basketball players participated in the shooting task of Experiment 1. The participants in the two groups wore an eye movement instrument while shooting the ball. The shooting techniques included free throws, 45° direct shots and 45° bank shots to verify the differences in shooting aiming points between expert basketball players and amateur basketball players. Forty-eight amateur basketball players participated in the teaching experiment of Experiment 2. Twenty-four participants participated in routine teaching, and 24 participants had shooting aiming point practice for nine weeks to verify the difference in FG% between the two groups. The shooting aiming points of the participants were assessed immediately after shooting. Results Experiment 1 found that expert basketball players used shorter fixation duration, fewer fixation numbers and more reasonable (simple and efficient) fixation distributions than amateur players. Moreover, expert basketball players took the front edge of the hoop as the aiming point, and amateur players took the central or back edge of the hoop as the aiming point; the FG% of the expert group (83.47%) was significantly higher than that of the amateur group (34.86%) (P < 0.01). Experiment 2 found that for the total FG% of the three tests, the intervention group (30.19%) was significantly higher than that of the control group (27.27%) (P < 0.05). After five weeks of aiming point training, it can be found that was no significant difference in the FG% between the intervention group (28.19%) and the control group (26.53%) (P > 0.05). After 9 weeks of shooting aiming point training, the FG% of the intervention group (36.39%) was significantly higher than that of the control group (30.14%) (P < 0.05), and the FG% of the intervention group increased faster than that of the control group. Additionally, the aiming point of the intervention players changed from the center and back edge of the hoop to the front. Conclusion (1) There was a correlation between basketball shooting aiming point and FG%. FG% with the front edge of the hoop as the aiming point was higher than the back edge hoop or center. (2) The FG% could be more quickly improved by shooting aiming point practice; it will not be affected in a short time (5 weeks); however, 9 weeks of practice can significantly improve the FG%.
Gou et al. (2022) Study on eye movement characteristics and intervention of basketball shooting skill. PeerJ 10:e14301 https://doi.org/10.7717/peerj.14301
Ethylene represses the promoting influence of cytokinin on cell division and expansion of cotyledons in etiolated Arabidopsis thaliana seedlings
The plant hormones ethylene and cytokinin influence many processes; sometimes they act cooperatively, other times antagonistically. To study their antagonistic interaction, we used the cotyledons of etiolated, intact seedlings of Arabidopsis thaliana. We focused on cell division and expansion, because both processes are quantified readily in paradermal sections. Here, we show that exogenous cytokinins modestly stimulate cell division and expansion in the cotyledon, with a phenyl-urea class compound exerting a larger effect than benzyl-adenine. Similarly, both processes were stimulated modestly when ethylene response was inhibited, either chemically with silver nitrate or genetically with the eti5 ethylene-insensitive mutant. However, combining cytokinin treatment with ethylene insensitivity was synergistic, strongly stimulating both cell division and expansion. Evidently, ethylene represses the growth promoting influence of cytokinin, whether endogenous or applied. We suggest that the intact etiolated cotyledon offers a useful system to characterize how ethylene antagonizes cytokinin responsiveness.
Stoynova-Bakalova et al. (2022) Ethylene represses the promoting influence of cytokinin on cell division and expansion of cotyledons in etiolated Arabidopsis thaliana seedlings. PeerJ 10:e14315 https://doi.org/10.7717/peerj.14315
Use of fermented spent coffee grounds as a substrate supplement for rearing black soldier fly larvae, Hermetia illucens (L), (Diptera: Stratiomyidae)
Background Spent coffee grounds (SCG), an increasingly abundant waste product with environmental disposal problems, has been used as a dietary supplement for many animals and have the potential to be used as a dietary supplement for black soldier fly (BSF) larvae; however, its effective use is still under scrutiny. To date, no studies have considered the use of SCG after microbial fermentation (fSCG) and its effects on BSF life history. Methods A mixture of fruit and vegetable pulp residue supplemented with one of six different fSCG percentages (0%, 20%, 40%, 60%, 80%, and 100% by weight) were provided as a diet substrate in order to evaluate the effect of the fSCG quantity on BSF growth, yield, and conversion ability. Results The addition of fSCG to the pulp diet prolonged larval development times, while 100% fSCG affected the larval survival rate and resulted in a male-biased adult sex ratio. The 20–40% fSCG and 40–60% fSCG treatments supported the largest prepupal and mature larval sizes, respectively. The highest waste reduction efficiency and feed conversion rate by BSF larvae was found with 20% fSCG, similar to the control (0% fSCG). Discussion From the short rearing time, high yield, and high bioconversion efficiency, a 20% fSCG supplementation of the mixed pulp was recommended for rearing BSF larvae. These data are valuable for coffee by-product waste management in urban areas.
Environmental Contamination and Remediation
Khaekratoke et al. (2022) Use of fermented spent coffee grounds as a substrate supplement for rearing black soldier fly larvae, Hermetia illucens (L), (Diptera: Stratiomyidae). PeerJ 10:e14340 https://doi.org/10.7717/peerj.14340
Prevention of polycystic ovary syndrome and postmenopausal osteoporosis by inhibiting apoptosis with Shenling Baizhu powder compound
Objective Shenling Baizhu powder (SBP) has been shown to reverse the abnormal expression of the aromatic hydrocarbon receptor (AHR) mediated by air pollution. Our study aimed to understand the main ingredient of SBP and investigate its action mechanism in preventing polycystic ovary syndrome (POCS) and postmenopausal osteoporosis (PMO). Methods The active ingredients of SBP with the highest binding affinity to AHR were screened using a Chinese medicine database, and their binding mechanism was simulated using molecular dynamics simulation (MDS). Rutin was utilized to treat ovarian granulosa cell lines and osteoblast cell lines. The cell lines were treated with a gradient of rutin concentration (0.01 mmol/L, 0.05 mmol/L and 0.1 mmol/L) to find the optimal drug dose. PCR was used to detect AHR and apoptosis-related proteins, and WB to detect the expression of AHR, caspase-3 and cleaved-caspase-3. Finally, the CCK-8 cell proliferation assay detected the proliferation of cells. Results We obtained Rutin through the Chinese medicine database, and dynamics simulation determined its binding sites. Ovarian granulosa cell lines and osteoblast cell lines were treated with Rutin. RT-PCR and western blotting revealed that the expression of apoptosis-associated protein Bcl-2 was elevated, and the expression of AHR, Bax, caspase-3 and PARP were decreased. CCK-8 results showed accelerated proliferation in both cell types. Conclusion Rutin, the main ingredient of SBP compound, works by binding to AHR, which can improve POCS and PMO by inhibiting cell apoptosis and by promoting cell proliferation.
Liang et al. (2022) Prevention of polycystic ovary syndrome and postmenopausal osteoporosis by inhibiting apoptosis with Shenling Baizhu powder compound. PeerJ 10:e13939 https://doi.org/10.7717/peerj.13939
Ambient particle characteristics by single particle aerosol mass spectrometry at a coastal site in Hong Kong: a case study affected by the sea-land breeze
The sea-land breeze (SLB) circulation plays a vital role in the transport of atmospheric pollutants in coastal cities. In this study, a single particle aerosol mass spectrometer (SPAMS) and combined bulk aerosol instruments were deployed to investigate the ambient particle characteristic at a suburban coastal site in Hong Kong from February 22 to March 10, 2013. Significant SLB circulations were captured from March 6–10, 2013, during the campaign. During the SLB periods, air quality worsened, with PM2.5 concentrations reaching a peak of 55.6 μg m−3 and an average value of 42.8 ± 4.5 μg m−3. A total of 235,894 particles were measured during the SLB stage. Eight major sources were identified by investigating the mixing states of the total particles, including the coal-burning related particles (48.1%), biomass burning particles (6.7%), vehicle emission-related particles (16.4%), sea salt (9.2%), ship emission particles (2.7%), dust/steeling industries (3.7%), waste incineration (6.3%), and road dust (3.9%). It was noteworthy that the PM2.5 concentrations and particle numbers increased sharply during the transition of land wind to the sea breeze. Meanwhile, the continental sourced pollutants recirculated back to land resulting in a cumulative increase in pollutants. Both individual and bulk measurements support the above results, with high contributions from coal burning, biomass burning, bulk K+, and NO3−, which were probably from the regional transportation from the nearby area. In contrast, the ship and vehicle emissions increased during the SLB period, with a high sulfate concentration partially originating from the ship emission. In this study, field evidence of continental-source pollutants backflow to land with the evolution of sea breeze was observed and helped our current understanding of the effect of SLB on air quality in the coastal city.
Wang et al. (2022) Ambient particle characteristics by single particle aerosol mass spectrometry at a coastal site in Hong Kong: a case study affected by the sea-land breeze. PeerJ 10:e14116 https://doi.org/10.7717/peerj.14116