Evolution of stomatal closure to optimize water-use efficiency in response to dehydration in ferns and seed plants.

Plants control water-use efficiency (WUE) by regulating water loss and CO2 diffusion through stomata. Variation in stomatal control has been reported among lineages of vascular plants, thus giving rise to the possibility that different lineages may show distinct WUE dynamics in response to water stress. Here, we compared the response of gas exchange to decreasing leaf water potential among four ferns and nine seed plant species exposed to a gradually intensifying water deficit. The data collected were combined with those from 339 phylogenetically diverse species obtained from previous studies. In well-watered angiosperms, the maximum stomatal conductance was high and greater than that required for maximum WUE, but drought stress caused a rapid reduction in stomatal conductance and an increase in WUE in response to elevated concentrations of abscisic acid. However, in ferns, stomata did not open beyond the optimum point corresponding to maximum WUE and actually exhibited a steady WUE in response to dehydration. Thus, seed plants showed improved photosynthetic WUE under water stress. The ability of seed plants to increase WUE could provide them with an advantage over ferns under drought conditions, thereby presumably increasing their fitness under selection pressure by drought.

Disease Progression in Patients with Parkin-Related Parkinson's Disease in a Longitudinal Cohort.

BACKGROUND: There was a paucity of follow-up studies in the disease progression of early-onset PD patients with Parkin mutations (Parkin-EOPD). Here we conducted a longitudinal study to investigate the progression of motor and cognitive features of Parkin-EOPD patients. METHODS: Genetic analysis was performed via target sequencing and multiplex ligation-dependent probe amplification. Thirty patients carrying homozygous or compound heterozygous Parkin mutations with at least 2 follow-up revisions were investigated as the Parkin-EOPD group. Fifty-two patients with at least 2 follow-up revisions, who did not have any known causative PD mutations, GBA or LRRK2 risk variants, a heterozygous Parkin mutation or 2 Parkin mutations without a segregation test, were defined as the genetically undefined EOPD (GU-EOPD) group. A linear mixed-effect model was implemented to evaluate longitudinal changes in motor symptoms and cognition. RESULTS: At baseline, the Parkin-EOPD group had a lower Unified Parkinson's Disease Rating Scale score (UPDRS-III) (off-medication) than the GU-EOPD group, without significant differences in cognition. A longitudinal study showed the estimated progression rate per year (standard error) of the UPDRS-III score (off-medication) was lower in the Parkin-EOPD group (0.203 [0.3162] points per year) than in the GU-EOPD group (1.056 [0.3001] points per year). The difference in the UPDRS-III score rate between the 2 groups was 0.853 (0.4183) (P = 0.042). The Parkin-EOPD group showed better maintenance of spatial processing ability compared with the GU-EOPD group (P = 0.027). CONCLUSION: Parkin-EOPD patients showed a slower deterioration of motor symptoms and a better spatial processing ability than GU-EOPD patients, which suggests that subtyping according to genetic features can help predict PD progression. © 2020 International Parkinson and Movement Disorder Society.

Behavioural thermoregulation by the endangered crocodile lizard (Shinisaurus crocodilurus) in captivity.

Understanding the factors that may affect behavioural thermoregulation of endangered reptiles is important for their conservation because thermoregulation determines body temperatures and in turn physiological functions of these ectotherms. Here we measured seasonal variation in operative environmental temperature (Te), body temperature (Tb), and microhabitat use of endangered crocodile lizards (Shinisaurus crocodilurus) from a captive population, within open and shaded enclosures, to understand how they respond to thermally challenging environments. Te was higher in open enclosures than in shaded enclosures. The Tb of lizards differed between the open and shaded enclosures in summer and autumn, but not in spring. In summer, crocodile lizards stayed in the water to avoid overheating, whereas in autumn, crocodile lizards perched on branches seeking optimal thermal environments. Crocodile lizards showed higher thermoregulatory effectiveness in open enclosures (with low thermal quality) than in shaded enclosures. Our study suggests that the crocodile lizard is capable of behavioural thermoregulation via microhabitat selection, although overall, it is not an effective thermoregulator. Therefore, maintaining diverse thermal environments in natural habitats for behavioural thermoregulation is an essential measure to conserve this endangered species both in the field and captivity.

Predictors to quality of life improvements after subthalamic stimulation in Parkinson's disease.

INTRODUCTION: Subthalamic deep brain stimulation (STN DBS) has been reported to improve the quality of life (QoL) related to Parkinson's disease (PD). However, not all subjects are satisfied with the postsurgical QoL outcome. We aimed to detect the related factors and possible predictors to QoL improvement for those PD patients one year after STN DBS. MATERIALS AND METHODS: A total of 45 PD patients with bilateral STN DBS surgery were included and followed up for 1 year. The Reliable Change Index (RCI) was adapted to determine the individual postsurgical QoL outcome. The changes of QoL were correlated with baseline parameters and the changes of progression parameters using Pearson's correlation. The exploratory stepwise regressions were adopted to detect the extents of baseline variables and progression parameters. The predictors to QoL outcome were detected using the logistic regression analysis. RESULTS: A total of 51.1% of the patients reported a better QoL, 40.0% of patients reported an unchanged QoL, while 8.9% of patients reported a worsening of QoL. The subdomains of mobility, activity of daily living, cognition, and bodily discomfort improved significantly after the surgery. The presurgical factors including QoL, dopaminergic medication burden, disease stages, depression scores, and postsurgical reductions in depression and nonmotor scores were found to correlate with QoL changes. Furthermore, the greater presurgical QoL burden, lesser dopaminergic medication exposure, and earlier disease stages were predictors to QoL improvements. CONCLUSION: The clinicians should carefully evaluate the nonmotor symptoms and life quality in those patients at relatively earlier stages and with lower medicine dosage to get more successful DBS outcomes.

Antidepressant-like effects of 20(S)-protopanaxadiol in a mouse model of chronic social defeat stress and the related mechanisms.

20(S)-Protopanaxadiol (PPD) is a basic aglycone of the dammarane triterpenoid saponins and exerts antidepressant-like effects on behaviour in the forced swimming test (FST) and tail suspension test (TST) and in rat olfactory bulbectomy depression models. However, the antidepressant effects of PPD have not been studied thoroughly. The objective of the present study was first to investigate the effect of PPD on depression behaviours induced by chronic social defeat stress (CSDS) in mice. The results showed that CSDS was effective in producing depression-like behaviours in mice, as indicated by decreased responses in the social interaction test, sucrose preference test, TST, and FST, and that this effect was accompanied by noticeable alterations in the levels of oxidative markers (superoxide dismutase, catalase, and lipid peroxidation) and monoamines (5-HT and NE) in the hippocampus and serum corticosterone levels. Additionally, western blot analysis revealed that CSDS exposure significantly downregulated BDNF, p-TrkB/TrkB, p-Akt/Akt, and p-mTOR/mTOR protein expression in the hippocampus. Remarkably, chronic PPD treatment significantly ameliorated these behavioral and biochemical alterations associated withCSDS-induced depression. Our results suggest that PPD exerts antidepressant-like effects in mice with CSDS-induced depression and that this effect may be mediated by the normalization of neurotransmitter and corticosterone levels and the alleviation of oxidative stress, as well as the enhancement of the PI3K/Akt/mTOR-mediated BDNF/TrkB pathway.

A homozygous missense variant in HSD17B4 identified in a consanguineous Chinese Han family with type II Perrault syndrome.

BACKGROUND: Perrault syndrome is a rare multisystem disorder that manifests with sensorineural hearing loss in both sexes, primary ovarian insufficiency in females and neurological features. The syndrome is heterogeneous both genetically and phenotypically. CASE PRESENTATION: We reported a consanguineous family (two affected sisters) with Perrault syndrome. The proband had the characteristics of Perrault syndrome: ovarian dysgenesis, bilateral hearing loss and obvious neurological signs. Target genetic sequencing and triplet repeat primed PCR (TP-PCR) plus capillary electrophoresis was conducted to detect causative mutations in the proband. The detected variant was further confirmed in the proband and tested in other family members by Sanger sequencing. Both the proband and her sister were found homozygous for the novel variant HSD17B4 c.298G > T (p.A100S) with their parents heterozygous. Detected by western blot, the protein expression of HSD17B4 mutant was much lower than that of the wild type in SH-SY5Y cells transfected by HSD17B4 wild type or mutant plasmid, which indicated the pathogenicity of the HSD17B4 mutation. CONCLUSIONS: Our findings supported that HSD17B4 was one of the genes contributing to Perrault syndrome with the likely pathogenic variant c.298G > T (p.A100S). Special manifestations of cerebellar impairment were found in cases caused by HSD17B4 mutations. Besides, attention should be paid to distinguish Perrault syndrome from D-bifunctional protein deficiency and hereditary ataxia.

Evaluation of PDQ-8 and its relationship with PDQ-39 in China: a three-year longitudinal study.

BACKGROUND: Parkinson's disease is characterized by motor and non-motor symptoms with wide ranging impacts on the health-related quality of life. The 39-item Parkinson's disease Questionnaire (PDQ-39) is the most widely used PD-specific health-related quality-of-life questionnaire. The short-form 8-item Parkinson's disease Questionnaire (PDQ-8) was found to produce results similar to that of the PDQ-39 cross-culturally. However, there is no evaluation of the PDQ-8 in the mainland of China. METHODS: In this longitudinal study, 283 patients with Parkinson's disease were recruited. The PDQ-39, the PDQ-8 and other scales were administered. Patients attended the clinic once annually for three years to complete the scales. RESULTS: The PDQ-8 was found to have good validity and reliability. There was a strong correlation between the summary indices of the PDQ-8 and the PDQ-39 (r=0.93, P<0.001). Results suggested that the PDQ-8 was also associated with other clinical scales of mobility, depression and cognition. The convergent validity and discriminant validity of the PDQ-8 were demonstrated by item-to-dimension correlations. There was acceptable internal consistency of the PDQ-8 (Cronbach's α: 0.80; Item-scale correlation efficient: 0.56-0.72). The PDQ-8 replicated the results of the PDQ-39 well at all follow-up time points (intraclass correlation coefficient: 0.96-0.98). In addition, there was good test-retest reliability of the PDQ-8. CONCLUSION: The PDQ-8 is a valid and reliable instrument assessing health-related quality of life for PD patients in the mainland of China.

Effectiveness and safety of Chinese massage therapy (Tui Na) on post-stroke spasticity: a prospective multicenter randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness and safety of Chinese massage therapy (Tui Na) for patients with post-stroke spasticity. DESIGN: A prospective, multicenter, blinded, randomized, placebo-controlled intervention trial. SUBJECT: A total of 90 patients with post-stroke spasticity were randomly assigned to the experimental (Tui Na therapy) group ( n = 45) or control (placebo Tui Na therapy) group ( n = 45). INTERVENTION: Participants in the experimental group received Tui Na therapy, while those in the control group received placebo-Tai Na (gentle rubbing) for 20-25 minutes per limb, once per day, five days per week for a total of four weeks. All participants in both groups received conventional rehabilitation. MAIN MEASURE: The Modified Ashworth Scale, the Fugl-Meyer Assessment and the Modified Barthel Index were used to assess the severity of spasticity, motor function of limbs and activities of daily living, respectively. Assessments were performed at baseline, at four weeks and at three months. RESULTS: Tui Na group had a significantly greater reduction in Modified Ashworth Scale in only four muscle groups than the control did (elbow flexors, P = 0.026; wrist flexors, P = 0.005; knee flexors, P = 0.023; knee extensors, P = 0.017). Improvements were sustained at three months follow-up. There was no significant difference between the two groups in Fugl-Meyer Assessment ( P = 0.503) and Modified Barthel Index ( P = 0.544). No adverse reaction was recorded in any of the cases mentioned at all study sites. CONCLUSIONS: Tui Na might be a safe and effective treatment to reduce post-stroke spasticity of several muscle groups.

[Antidepressant effects of the extract of Dendrobium nobile Lindl on chronic unpredictable mild stress-induced depressive mice].

To investigate whether the extract of Dendrobium nobile Lindl (DNL) has an antidepressant effect on chronic unpredictable mild stress (CUMS)-induced depressive mice, 72 BALB/c male mice were randomly divided into the control group, the CUMS model group, the extract of DNL groups (50, 100 and 200 mg/kg DNL, i.g.) and the paroxetine group (10 mg/kg, i.g.). The different doses of DNL or the paroxetine was administered orally once daily to CUMS mice for 8 weeks (containing two-week preventive medication before the modeling). The same volume of distilled water was given to the control group and the CUMS group. Except for the control group, the other mice were exposed to chronic stress for 35 days. Behavioral tests were performed by using the sucrose preference test (SPT), the novelty-suppressed feeding (NSF) test, the tail suspension test (TST), and the forced swim test (FST). The levels of dopamine (DA) and 5-hydroxytryptamine (5-HT) were measured by the liquid chromatography-mass spectrometer (LC-MS)/MS. Compared with the control group, obvious behavioral changes were observed in the CUMS group after 5-week CUMS, including a decrease in the sucrose consumption, an increase in the latency to feeding in the NSF test and a prolongation of the immobility time in the TST. Compared with the CUMS group, the application of DNL resulted in a dose-dependent increase in sucrose consumption (P < 0.01) as paroxetine (10 mg/kg) did and a significant dose-dependent decrease in the latency to feeding in the NSF test (P < 0.05). In the TST, the application of paroxetine (10 mg/kg) and the high-dose DNL (200 mg/kg) obviously decreased the immobility time when compared with the CUMS group (P < 0.05). In the FST, compared with the CUMS group, all the groups had no significant differences in the immobility time (P > 0.05). In addition, in the hippocampus and cortex, the levels of 5-HT and DA were significantly decreased in the CUMS group compared with the control group (P < 0.05). In comparison with the CUMS group, paroxetine obviously increased the DA levels in the hippocampus and the cortex and the 5-HT level in the hippocampus (P < 0.05). DNL (50 and 200 mg/kg) significantly increased the DA level in cerebral cortex of the brain, and DNL (100 and 200 mg/kg) increased the DA level in the hippocampus. The 5-HT level in the 200 mg/kg DNL group was notably increased in both two brain regions (P < 0.05), but the 5-HT level in the 100 mg/kg DNL group was significantly increased only in the hippocampus (P < 0.01). These findings indicate that the extract of DNL has an antidepressant-like effect on CUMS-induced depressive mice and its mechanism may be related to the changes in DA and 5-HT in the hippocampus and cortex.

Tai Chi for improving cardiopulmonary function and quality of life in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis.

OBJECTIVE: To examine the effect of Tai Chi on cardiopulmonary function and quality of life in chronic obstructive pulmonary disease. DATA SOURCES: Cochrane Library, PUBMED, EMBASE, China Biology Medicine disc, China National Knowledge Infrastructure, and Wanfang database. METHODS: Articles on randomized controlled trials comparing Tai Chi with other treatments or no treatment were identified. A random-effects model was used to calculate the pooled mean difference (MD) with 95% confidence interval (CI). RESULTS: Fifteen articles involving 1354 participants were included. Compared with the control group, Tai Chi was more effective in improving exercise capacity on 6-minute walking distance (short term: MD = 16.02, 95% CI 2.86 to 29.17; mid term: MD = 30.90, 95% CI 6.88 to 54.93; long term: MD = 24.63, 95% CI 2.30 to 46.95), as well as pulmonary functions on forced expiratory volume in the first second (mid term: MD = 0.10; 95% CI 0.01 to 0.19), and forced vital capacity (mid term: MD = 0.20; 95% CI 0.04 to 0.36). Concerning quality of life, we found Tai Chi was better than the control group for the Chronic Respiratory Disease Questionnaire dyspnoea score (short term: MD = 0.90; 95% CI 0.51 to 1.29), fatigue score (short term: MD = 0.75; 95% CI 0.42 to 1.09), and total score (short term: MD = 1.92; 95% CI 0.54 to 3.31). CONCLUSIONS: Tai Chi may improve exercise capacity in the short, mid, and long terms. However, no significant long term differences in pulmonary function and quality of life were observed for patients with chronic obstructive pulmonary disease.

Bilateral Neuropathy of Primary Sensory Neurons by the Chronic Compression of Multiple Unilateral DRGs.

To mimic multilevel nerve root compression and intervertebral foramina stenosis in human, we established a new animal model of the chronic compression of unilateral multiple lumbar DRGs (mCCD) in the rat. A higher occurrence of signs of spontaneous pain behaviors, such as wet-dog shaking and spontaneous hind paw shrinking behaviors, was firstly observed from day 1 onward. In the meantime, the unilateral mCCD rat exhibited significant bilateral hind paw mechanical and cold allodynia and hyperalgesia, as well as a thermal preference to 30°C plate between 30 and 35°C. The expression of activating transcription factor 3 (ATF3) was significantly increased in the ipsilateral and contralateral all-sized DRG neurons after the mCCD. And the expression of CGRP was significantly increased in the ipsilateral and contralateral large- and medium-sized DRG neurons. ATF3 and CGRP expressions correlated to evoked pain hypersensitivities such as mechanical and cold allodynia on postoperative day 1. The results suggested that bilateral neuropathy of primary sensory neurons might contribute to bilateral hypersensitivity in the mCCD rat.

Berberine ameliorates renal interstitial fibrosis induced by unilateral ureteral obstruction in rats.

AIM: To investigate the potential effects of berberine on renal interstitial fibrosis (RIF) of obstructed kidneys in a unilateral ureteral obstruction (UUO) rat model. METHODS: Forty-eight rats were randomly divided into three groups: sham-operated, vehicle-treated UUO, and berberine-treated UUO. Rats were gavaged with berberine (200 mg/kg per day) or vehicle. Eight randomly chosen rats in each group were kiled and specimens were collected at day 14 after UUO. Physiological parameters and histological changes were assessed, RIF was evaluated using Masson's trichrome and Sirius red staining, oxidative stress and inflammation markers were determined, transforming growth factor ß1 (TGF-ß1), phosphorylated Smad3 (pSmad3) and α-smooth muscle actin (α-SMA) were measured using immunohistochemistry or western blotting analysis. The obstruction was relieved at day 14 by percutaneous nephrostomy in the remaining UUO rats. The resistive index of left kidneys was undertaken by coloured Doppler flow imaging at day 14 before nephrostomy and day 7 after the relief. RESULTS: Berberine treatment significantly attenuated RIF induced by UUO. The UUO-induced reduction in kidney superoxide dismutase and catalase activities increased, whereas elevated kidney malondialdehyde level markedly decreased. Berberine treatment significantly ameliorated UUO-induced inflammation, and decreased TGF-ß1, pSmad3 and α-SMA expression of UUO kidneys. Moreover, berberine treatment significantly suppressed the increase of resistive index compared with UUO group at day 14 after UUO as well as day 7 after the relief of obstruction. CONCLUSION: Berberine treatment ameliorates RIF in a UUO rat model by inhibition of oxidative stress, inflammatory responses, and TGF-ß1/pSmad3 signalling.

Blockade of spinal dopamine D1/D2 receptor heteromers by levo-Corydalmine suppressed calcium signaling cascade in spinal neurons to alleviate bone cancer pain in rats.

Background: Dopamine receptors have been reported to be involved in pain, while the exact effects and mechanism in bone cancer pain have not been fully explored. Methods: Bone cancer pain model was created by implanting walker 256 mammary gland carcinoma into right tibia bone cavity. Primary cultured spinal neurons were used for in vitro evaluation. FLIPR, western-blot, immunofluorescence, and Co-IP were used to detect cell signaling pathway. Results: Our results indicated that spinal dopamine D1 receptor (D1DR) and spinal dopamine D2 receptor (D2DR) could form heteromers in TCI rats, and antagonizing spinal D1DR and D2DR reduced heteromers formation and alleviated TCI-induced bone cancer pain. Further results indicated that D1DR or D2DR antagonist induced antinociception in TCI rats could be reversed by D1DR, D2DR, and D1/D2DR heteromer agonists. And Gq, IP3, and PLC inhibitors also attenuated TCI-induced bone cancer pain. In vitro results indicated that D1DR or D2DR antagonist decreased the Ca2+ oscillations upregulated by D1DR, D2DR, and D1/D2DR heteromer agonists in activated primary cultured spinal neurons. Moreover, inhibition of D1/D2DR heteromers induced antinociception in TCI rats was partially mediated by the CaMKII and MAPKs pathway. In addition, a natural compound levo-Corydalmine (l-CDL), could inhibit D1/D2DR heteromers and attenuate bone cancer pain. Results: Inhibition of spinal D1/D2DR heteromers via l-CDL decreases excitability in spinal neurons, which might present new therapeutic strategy for bone cancer pain.

Root-associated bacteria strengthen their community stability against disturbance of antibiotics on structure and functions.

Antibiotics affect bacterial community structure and functions in soil. However, the response and adaptation of root-associated bacterial communities to antibiotic stress remains poorly understood. Here, rhizobox experiments were conducted with maize (Zea mays L.) upon exposure to antibiotics ciprofloxacin or tetracycline. High-throughput sequencing analysis of bacterial community and quantitative PCR analysis of nitrogen cycling genes show that ciprofloxacin and tetracycline significantly shift bacterial community structure in bulk soil, whereas plant host may mitigate the disturbances of antibiotics on bacterial communities in root-associated niches (i.e., rhizosphere and rhizoplane) through the community stabilization. Deterministic assembly, microbial interaction, and keystone species (e.g., Rhizobium and Massilia) of root-associated bacterial communities benefit the community stability compared with those in bulk soil. Meanwhile, the rhizosphere increases antibiotic dissipation, potentially reducing the impacts of antibiotics on root-associated bacterial communities. Furthermore, rhizospheric effects deriving from root exudates alleviate the impacts of antibiotics on the nitrogen cycle (i.e., nitrification, organic nitrogen conversion and denitrification) as confirmed by functional gene quantification, which is largely attributed to the bacterial community stability in rhizosphere. The present study enhances the understanding on the response and adaptation of root-associated bacterial community to antibiotic pollution.

Notch signaling controls generation of motor neurons in the lesioned spinal cord of adult zebrafish.

In mammals, increased Notch signaling is held partly responsible for a lack of neurogenesis after a spinal injury. However, this is difficult to test in an essentially nonregenerating system. We show that in adult zebrafish, which exhibit lesion-induced neurogenesis, e.g., of motor neurons, the Notch pathway is also reactivated. Although apparently compatible with neuronal regeneration in zebrafish, forced activity of the pathway significantly decreased progenitor proliferation and motor neuron generation. Conversely, pharmacological inhibition of the pathway increased proliferation and motor neuron numbers. This demonstrates that Notch is a negative signal for regenerative neurogenesis, and, importantly, that spinal motor neuron regeneration can be augmented in an adult vertebrate by inhibiting Notch signaling.

Induction of apoptosis through caspase-independent or caspase-9-dependent pathway in mouse and human osteosarcoma cells by a new nitroxyl spin-labeled derivative of podophyllotoxin.

Previous study has found that a new nitroxyl spin-labeled derivative of podophyllotoxin, 4-[4"-(2",2",6",6"-tetramethyl-1"-piperidinyloxy)amino]-4'-demethyl-epipodophyllotoxin (GP7), can induce apoptosis in human leukemia cells. However, there have been no studies about the effects of GP7 on osteosarcoma (OS) cells. Here, we observed the anti-OS effects of GP7 in mouse and human OS cells with the comparison of etoposide. GP7 and etoposide inhibited the proliferation of a panel of mouse and human OS cells in a concentration- or time-dependent manner, and the inhibitory effect of GP7 on the proliferation of mouse LM8 or human U2OS cells was 1.28- or 1.35-fold higher than that of etoposide. GP7 or etoposide augmented the anti-OS effects of methotrexate, adriamycin, cisplatin, or their combination, and the combined inhibitory effects of GP7 with MTX on the proliferation of LM8 cells was higher than those of etoposide with MTX. GP7 arrested the cell cycle in S phase but etoposide in G(2)/M phase. GP7 or etoposide induced sub-G(1) peak, apoptotic DNA fragmentation, activations of caspase-3, -8, -9, and DNA fragmentation factor, downregulation of Bcl-2 and Bcl-xL, upregulation of Bax and Bak, and cytochrome-c release from mitochondria in both mouse and human OS cells. GP7 or etoposide also induced endonuclease G translocation from mitochondria into cytosol in mouse cells. GP7- or etoposide-induced apoptotic DNA fragmentation of human OS cells was inhibited by the pan caspase inhibitor and caspase-9 inhibitor, not by caspase-8 inhibitor whereas it was not inhibited by the pan caspase inhibitor in mouse OS cells. Our findings indicate that GP7 is effective against mouse and human OS cells in vitro. The apoptotic DNA fragmentation in mouse OS cells may be mediated by caspase-independent pathway with the involvement of endonuclease G whereas in human OS cells by caspase-9-dependent pathway downstream of the cytochrome-c-initiated caspase cascade.

Effects of microplastics on seed germination and seedling physiological characteristics of Spinacia oleracea under alkali stress.

Microplastics, a type of new environmental pollutant, have received much attention for their negative effects on organisms and environment. We examined the effects of microplastics on seed germination and seedling physiological characteristics of spinach (Spinacia oleracea) under alkali stress, taking polystyrene microspheres with a diameter of 100 nm (200, 400, 800, 1600 mg·L-1) as the microplastic treatment, and mixed NaHCO3 and Na2CO3 as alkaline salt solution (5, 10, 20, 40 mmol·L-1) according to the molar ratio of 1:1. The results showed that the presence of MPs (≥400 mg·L-1) inhibited seed germination, and that the length of roots and shoots increased at low while decreased at high concentration of MPs. Different concentrations of alkali alone could inhibit seed germination, root and bud elongation. With the increases of MPs concentration, SOD activity of spinach seedlings gradually decreased, while POD activity firstly increased and then decreased, and chlorophyll content increased at low concentration (200 mg·L-1) and decreased significantly at medium and high concentration (≥400 mg·L-1). Different alkali stresses reduced chlorophyll content of spinach seedlings, and the effects on SOD and POD were 'promotion at low concentration and inhibition at high'. In the treatments of microplastics (200, 800 mg·L-1) and alkali (5, 20 mmol·L-1) combined exposure, germination of spinach seeds was inhibited, and chlorophyll content decreased. The activities of SOD and POD in spinach seedlings were reduced under the combined exposure except the treatment of 200 mg·L-1 MPs and 5 mmol·L-1 alkali. Compared to the alkali stress, the combination of low concentration of MPs (200 mg·L-1) and alkali could improve germination rate, germination index, germination vigor and vigor index of seeds, and significantly promoted the elongation of roots and shoots, while the addition of high concentration of MPs (800 mg·L-1) reduced the germination rate, germination index, germination vigor and vigor index of seeds and inhibited the growth of roots and buds. The different concentrations of combined exposure inhibited the activities of SOD and POD and decreased the content of chlorophyll in spinach seedlings.

Ethylene constrains stomatal reopening in Fraxinus chinensis post moderate drought.

Clarifying the mechanisms underlying the recovery of gas exchange following drought is the key to providing insights into plant drought adaptation and habitat distribution. However, the mechanisms are still largely unknown. Targeting processes known to inhibit gas exchange during drought recovery, we measured leaf water potential, the leaf hydraulic conductance, stomatal reopening, abscisic acid (ABA) and the ethylene emission rate (EER) following moderate drought stress in seedlings of the globally pervasive woody tree Fraxinus chinensis. We found strong evidence that the slow stomatal reopening after rehydration is regulated by a slow decrease in EER, rather than changes in leaf hydraulics or foliar ABA levels. This was supported by evidence of rapid gas exchange recovery in plants after treatment with the ethylene antagonist 1-methylcyclopropene. These findings provide evidence to rigorously support ethylene as a key factor constraining stomatal reopening from moderate drought directly, thereby potentially opening new windows for understanding species drought adaptation.

PDQ-8: A Simplified and Effective Tool Measuring Life Quality in Progressive Supranuclear Palsy.

BACKGROUND: The self-reported quality of life (QoL) should be carefully listened to in progressive supranuclear palsy (PSP) from the patient-centered perspective. However, there was still a lack of short QoL measurement tool in atypical parkinsonism. OBJECTIVE: We aimed to test whether the short Parkinson's Disease Questionnaire-8 (PDQ-8) was effective in assessing QoL in PSP, comparing with Progressive Supranuclear Palsy Quality of Life Scale (PSP-QoL) and Parkinson's Disease Questionnaire-39 (PDQ-39). METHODS: 132 patients with clinical diagnosed PSP, including PSP-Richardson syndrome (RS) subtype (n = 71) and PSP-non-RS subtype (n = 61) were recruited for clinical evaluation including QoL assessment. The detailed QoL profiles and possibility of using PDQ-8 were systemically analyzed. The determinants to the QoL were then calculated by multivariate linear regression analysis. RESULTS: The PSP-QoL total score summary index (SI) was 22.8 (10.1, 41.1), while the PDQ-8 and PDQ-39 total SI score were 28.1 (12.5, 46.9) and 29.5 (15.4, 49.4). Mobility, activities of daily life, cognition and communication were the main affected QoL subdomains (median SI: 40.0, 31.3, 25.0 and 25.0 respectively). PSP-RS subtype showed more severe damage physically (p<0.001) and mentally (p = 0.002) compared to other subtypes. More importantly, the strong relevance of PDQ-8 and recommended PSP QoL tools were confirmed (p<0.001). In addition, disease severity, depression and daytime sleepiness were proved to be critical determinants for QoL in PSP. CONCLUSIONS: PDQ-8 could be an easy, reliable, and valid tool to evaluate QoL in patients with PSP. Besides motor symptoms, more attention should be paid to non-motor impairment such as depression in PSP.

Adaptation of bacterial community in maize rhizosphere for enhancing dissipation of phthalic acid esters in agricultural soil.

Rhizospheric degradation is a green and in situ strategy to accelerate dissipation of organic pollutants in soils. However, the mechanism on microbial degradation of phthalic acid esters (PAEs) in rhizosphere is still unclear. Here, the bacterial community and function genes in bulk and rhizospheric soils of maize (Zea mays L.) exposed to gradient concentrations of di-(2-ethylhexyl) phthalate (DEHP) were analyzed with 16 S rRNA, metagenomic sequencing and quantitative PCR (qPCR). Maize rhizosphere significantly increased the dissipation of DEHP by 4.02-11.5% in comparison with bulk soils. Bacterial community in rhizosphere exhibited more intensive response and shaped its beneficial structure and functions to DEHP stress than that in bulk soils. Both rhizospheric and pollution effects enriched more PAE-degrading bacteria (e.g., Bacillus and Rhizobium) and function genes in rhizosphere than in bulk soil, which played important roles in degradation of PAEs in rhizosphere. The PAE-degrading bacteria (including genera Sphingomonas, Sphingopyxis and Lysobacter) identified as keystone species participated in DEHP biodegradation. Identification of PAE intermediates and metagenomic reconstruction of PAE degradation pathways demonstrated that PAE-degrading bacteria degraded PAEs through cooperation with PAE-degrading and non-PAE-degrading bacteria. This study provides a comprehensive knowledge for the microbial mechanism on the superior dissipation of PAEs in rhizosphere.