S-nitrosylation may inhibit the activity of COP1 in plant photomorphogenesis.

Protein S-nitrosylation, which is defined by the covalent attachment of nitric oxide (NO) to the thiol group of cysteine residues, is known to play critical roles in plant development and stress responses. NO promotes seedling photomorphogenesis and NO emission is enhanced by light. However, the function of protein S-nitrosylation in plant photomorphogenesis is largely unknown. E3 ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) and transcription factor ELONGATED HYPOCOTYL 5 (HY5) antagonistically regulate seedling photomorphogenesis. COP1 inhibits plant photomorphogenesis by targeting photomorphogenic promoters like HY5 for 26S proteasome degradation. Here, we report that COP1 is S-nitrosylated in vitro. Mass spectrometry analyses revealed that two evolutionarily well conserved residues, cysteine 425 and cysteine 607, in the WD40 domain of COP1 are S-nitrosylated. S-nitrosylated glutathione (GSNO) is an important physiological NO donor for protein S-nitrosylation. The Arabidopsis (Arabidopsis thaliana) gsnor1-3 mutant, which accumulates higher level of GSNO, accumulated higher HY5 levels than wildtype (WT), indicating that COP1 activity is inhibited. Protein S-nitrosylation can be reversed by Thioredoxin-h5 (TRXh5) in plants. Indeed, COP1 interacts directly with TRXh5 and its close homolog TRXh3. Moreover, catalase 3 (CAT3) acts as a transnitrosylase that transfers NO to its target proteins like GSNO reductase (GSNOR). We found that CAT3 interacts with COP1 in plants. Taken together, our data indicate that the activity of COP1 is likely inhibited by NO via S-nitrosylation to promote the accumulation of HY5 and photomorphogenesis.

Regionally Compatible Individual Tree Growth Model under the Combined Influence of Environment and Competition.

To explore the effects of competition, site, and climate on the growth of Chinese fir individual tree diameter at breast height (DBH) and tree height (H), a regionally compatible individual tree growth model under the combined influence of environment and competition was constructed. Using continuous forest inventory (CFI) sample plot data from Fujian Province between 1993 and 2018, we constructed an individual tree DBH model and an H model based on re-parameterization (RP), BP neural network (BP), and random forest (RF), which compared the accuracy of the different modeling methods. The results showed that the inclusion of competition and environmental factors could improve the prediction accuracy of the model. Among the site factors, slope position (PW) had the most significant effect, followed by elevation (HB) and slope aspect (PX). Among the climate factors, the highest contribution was made by degree-days above 18 °C (DD18), followed by mean annual precipitation (MAP) and Hargreaves reference evaporation (Eref). The comparison results of the three modeling methods show that the RF model has the best fitting effect. The R2 of the individual DBH model based on RF is 0.849, RMSE is 1.691 cm, and MAE is 1.267 cm. The R2 of the individual H model based on RF is 0.845, RMSE is 1.267 m, and MAE is 1.153 m. The model constructed in this study has the advantages of environmental sensitivity, statistical reliability, and prediction efficiency. The results can provide theoretical support for management decision-making and harvest prediction of mixed uneven-aged forest.

The Time-Lag Effect of Climate Factors on the Forest Enhanced Vegetation Index for Subtropical Humid Areas in China.

Forests represent the greatest carbon reservoir in terrestrial ecosystems. Climate change drives the changes in forest vegetation growth, which in turn influences carbon sequestration capability. Exploring the dynamic response of forest vegetation to climate change is thus one of the most important scientific questions to be addressed in the precise monitoring of forest resources. This paper explores the relationship between climate factors and vegetation growth in typical forest ecosystems in China from 2007 to 2019 based on long-term meteorological monitoring data from six forest field stations in different subtropical ecological zones in China. The time-varying parameter vector autoregressive model (TVP-VAR) was used to analyze the temporal and spatial differences of the time-lag effects of climate factors, and the impact of climate change on vegetation was predicted. The enhanced vegetation index (EVI) was used to measure vegetation growth. Monthly meteorological observations and solar radiation data, including precipitation, air temperature, relative humidity, and photosynthetic effective radiation, were provided by the resource sharing service platform of the national ecological research data center. It was revealed that the time-lag effect of climate factors on the EVI vanished after a half year, and the lag accumulation tended to be steady over time. The TVP-VAR model was found to be more suitable than the vector autoregressive model (VAR). The predicted EVI values using the TVP-VAR model were close to the true values with the root mean squares error (RMSE) < 0.05. On average, each site improved its prediction accuracy by 14.81%. Therefore, the TVP-VAR model can be used to analyze the relationship of climate factors and forest EVI as well as the time-lag effect of climate factors on vegetation growth in subtropical China. The results can be used to improve the predictability of the EVI for forests and to encourage the development of intensive forest management.

ROS-stimulated protein lysine acetylation is required for crown root development in rice.

INTRODUCTION: As signal molecules in aerobic organisms, locally accumulated ROS have been reported to balance cell division and differentiation in the root meristem. Protein posttranslational modifications such as lysine acetylation play critical roles in controlling a variety of cellular processes. However, the mechanism by which ROS regulate root development is unknown. In addition, how protein lysine acetylation is regulated and whether cellular ROS levels affect protein lysine acetylation remain unclear. OBJECTIVES: We aimed to elucidate the relationship between ROS and protein acetylation by exploring a rice mutant plant that displays a decreased level of ROS in postembryonic crown root (CR) cells and severe defects in CR development. METHODS: First, proteomic analysis was used to find candidate proteins responsible for the decrease of ROS detected in the wox11 mutant. Then, biochemical, molecular, and genetic analyses were used to study WOX11-regulated genes involved in ROS homeostasis. Finally, acetylproteomic analysis of wild type and wox11 roots treated with or without potassium iodide (KI) and hydrogen peroxide (H2O2) was used to study the effects of ROS on protein acetylation in rice CR cells. RESULTS: We demonstrated that WOX11 was required to maintain ROS homeostasis by upregulating peroxidase genes in the crown root meristem. Acetylproteomic analysis revealed that WOX11-dependent hydrogen peroxide (H2O2) levels in CR cells promoted lysine acetylation of many non-histone proteins enriched for nitrogen metabolism and peptide/protein synthesis pathways. Further analysis revealed that the redox state affected histone deacetylases (HDACs) activity, which was likely related to the high levels of protein lysine acetylation in CR cells. CONCLUSION: WOX11-controlled ROS level in CR meristem cells is required for protein lysine acetylation which represents a mechanism of ROS-promoted CR development in rice.

LncRNA-UC.25 + shRNA Alleviates P2Y14 Receptor-Mediated Diabetic Neuropathic Pain via STAT1.

Diabetic neuropathic pain (DNP) is a common complication of diabetes, and its complicated pathogenesis, as well as clinical manifestations, has brought great trouble to clinical treatment. The spinal cord is an important part of regulating the occurrence and development of DNP. Spinal microglia can regulate the activity of spinal cord neurons and have a regulatory effect on chronic pain. P2Y12 receptor is involved in DNP. P2Y14 and P2Y12 receptors belong to the Gi subtype of P2Y receptors, but there is no report that the P2Y14 receptor is involved in DNP. Closely related to many human diseases, the dysregulation of long noncoding RNA (lncRNA) has the effect of promoting or inhibiting the occurrence and development of diseases. The aim of this research is to investigate the function of the spinal cord P2Y14 receptor in type 2 DNP and to understand the function as well as the possible mechanism of lncRNA-UC.25 + (UC.25 +) in rat spinal cord P2Y14 receptor-mediated DNP. Our results showed that P2Y14 shRNA can reduce the expression of P2Y14 in DNP rats, thereby restraining the activation of microglia, decreasing the expression of inflammatory factors and the level of p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation. At the same time, UC.25 + shRNA can downregulate the expression of the P2Y14 receptor, reduce the release of inflammatory factors, and diminish the p38 MAPK phosphorylation, indicating that UC.25 + can alleviate spinal cord P2Y14 receptor-mediated DNP. The RNA immunoprecipitation result showed that UC.25 + enriched signal transducers and activators of transcription1 (STAT1) and positively regulated its expression. The chromatin immunoprecipitation result indicated that STAT1 combined with the promoter region of the P2Y14 receptor and positively regulated the expression of the P2Y14 receptor. Therefore, we infer that UC.25 + may alleviate DNP in rats by regulating the expression of the P2Y14 receptor in spinal microglia via STAT1.

Parental variation in CHG methylation is associated with allelic-specific expression in elite hybrid rice.

Heterosis refers to the superior performance of hybrid lines over inbred parental lines. Besides genetic variation, epigenetic differences between parental lines are suggested to contribute to heterosis. However, the precise nature and extent of differences between the parental epigenomes and the reprograming in hybrids that govern heterotic gene expression remain unclear. In this work, we analyzed DNA methylomes and transcriptomes of the widely cultivated and genetically studied elite hybrid rice (Oryza sativa) SY63, the reciprocal hybrid, and the parental varieties ZS97 and MH63, for which high-quality reference genomic sequences are available. We showed that the parental varieties displayed substantial variation in genic methylation at CG and CHG (H = A, C, or T) sequences. Compared with their parents, the hybrids displayed dynamic methylation variation during development. However, many parental differentially methylated regions (DMRs) at CG and CHG sites were maintained in the hybrid. Only a small fraction of the DMRs displayed non-additive DNA methylation variation, which, however, showed no overall correlation relationship with gene expression variation. In contrast, most of the allelic-specific expression (ASE) genes in the hybrid were associated with DNA methylation, and the ASE negatively associated with allelic-specific methylation (ASM) at CHG. These results revealed a specific DNA methylation reprogramming pattern in the hybrid rice and pointed to a role for parental CHG methylation divergence in ASE, which is associated with phenotype variation and hybrid vigor in several plant species.

Neferine alleviates P2X3 receptor in rat dorsal root ganglia mediated neuropathic pain.

Chronic neuropathic pain is caused by tissue damage or nervous system inflammation and is characterized by sensitivity to painful stimuli. P2X3 receptors play an important role in facilitating pain transmission. Neferine is a bisbenzylisoquinline alkaloid isolated from seed embryos of lotus, which has anti-inflammatory and anti-oxidation pharmacological functions. The present research investigated whether neferine relieves neuropathic pain related to the P2X3 receptor in rat dorsal root ganglia (DRGs). Chronic contraction injury (CCI) in rats was used as a model for neuropathic pain. The results indicated that the expression of P2X3 receptor was significantly increased in the DRGs of CCI rats and that mechanical allodynia and thermal hyperalgesia were also enhanced in CCI rats. Neferine markedly lowered the upregulated P2X3 receptor and interleukin-1beta, inhibited the phosphorylation and activation of ERK1/2 in the DRGs of CCI rats, and relieved neuropathic pain. Therefore, neferine alleviates neuropathic pain by downregulating the expression of P2X3 receptor.

Osthole relieves diabetics cardiac autonomic neuropathy associated with P2X3 receptor in ratstellate ganglia.

Diabetic cardiac autonomic neuropathy (DCAN) is a serious complication of diabetes mellitus, which often leads to cardiac dysfunction and even threatens patients' life. Osthole, a natural coumarin derivative, has anti-inflammatory, anti-oxidant and antihypertensive effects. The P2X3 receptor is related to DCAN. The objective of this study will investigate whether osthole relieves DCAN associated with the P2X3 receptor in the stellate ganglia of diabetic rats. A type 2 diabetes mellitus rat model was induced by a combination of diet and streptozotocin. Our results showed that osthole improved the abnormal changes of blood pressure, heart rate, and heart rate variability in diabetic rats and significantly reduced the up-regulated expression levels of the P2X3 receptor, tumor necrosis factor-α and interleukin-1ß in stellate ganglia of diabetic rats. Meanwhile, osthole significantly decreased the elevated serum adrenaline concentration and phosphorylation level of extracellular regulated protein kinase 1/2. In addition, the molecular docking result indicated that osthole was a perfect fit for interacting with the P2X3 receptor. Overall, osthole alleviates the sympathetic relative excitation via inhibiting the expression of P2X3 receptors in the stellate ganglia, to achieve a balance between sympathetic and parasympathetic nerves, relieves the DCAN.

Anode-biofilm electron transfer behavior and wastewater treatment under different operational modes of bioelectrochemical system.

Anode-biofilm electron transfer behavior was investigated during the advanced wastewater treatment process by three bioelectrochemical systems (BESs): microbial fuel cell (MFC), MFC operated under short circuit condition (MSC), and microbial electrolysis cell (MEC). Under different operational modes, current produced by the anode biofilm varied from 0.92, 4.15 to 8.21mA in the sequence of MFC, MSC and MEC, respectively. The cyclic voltammetry test on the anode biofilm suggested that the current generation was achieved via various bioelectroactive species with formal potentials at -0.473, -0.402 and -0.345V (vs. SCE). Gibbs free energy and charge transfer resistance data demonstrated that different amounts of available bioelectroactive species functioned in different BESs. The comparative investigation among MFC, MSC and MEC suggested that MEC was the only feasible operational mode for advanced wastewater treatment, because of its superior current generation capability.