Glioma stem cell-derived exosomes induce the transformation of astrocytes via the miR-3065-5p/DLG2 signaling axis.

Tumor-associated astrocytes (TAAs) in the glioblastoma microenvironment play an important role in tumor development and malignant progression initiated by glioma stem cells (GSCs). In the current study, normal human astrocytes (NHAs) were cultured and continuously treated with GSC-derived exosomes (GSC-EXOs) induction to explore the mechanism by which GSCs affect astrocyte remodeling. This study revealed that GSC-EXOs can induce the transformation of NHAs into TAAs, with relatively swollen cell bodies and multiple extended processes. In addition, high proliferation, elevated resistance to temozolomide (TMZ), and increased expression of TAA-related markers (TGF-ß, CD44, and tenascin-C) were observed in the TAAs. Furthermore, GSC-derived exosomal miR-3065-5p could be delivered to NHAs, and miR-3065-5p levels increased significantly in TAAs, as verified by miRNA expression profile sequencing and Reverse transcription polymerase chain reaction. Overexpression of miR-3065-5p also enhanced NHA proliferation, elevated resistance to TMZ, and increased the expression levels of TAA-related markers. In addition, both GSC-EXO-induced and miR-3065-5p-overexpressing NHAs promoted tumorigenesis of GSCs in vivo. Discs Large Homolog 2 (DLG2, downregulated in glioblastoma) is a direct downstream target of miR-3065-5p in TAAs, and DLG2 overexpression could partially reverse the transformation of NHAs into TAAs. Collectively, these data demonstrate that GSC-EXOs induce the transformation of NHAs into TAAs via the miR-3065-5p/DLG2 signaling axis and that TAAs can further promote the tumorigenesis of GSCs. Thus, precisely blocking the interactions between astrocytes and GSCs via exosomes may be a novel strategy to inhibit glioblastoma development, but more in-depth mechanistic studies are still needed.

The cognitive appraisal path of stroke knowledge, coping traits, family functioning and stigma among stroke patients: A moderated parallel mediation model.

AIMS: To establish a cognitive appraisal path model that examines the impact of stroke knowledge on stigma with the parallel mediating effects of negative and positive coping traits, as well as the moderating effects of family functioning. BACKGROUND: Stroke-related stigma, a 'mixture' of negative emotions involving internal criticism and external judgement, has been shown to impair patients' health outcomes. However, the specific factors underlying cognitive appraisals and their pathways remain unknown. DESIGN: A cross-sectional design. METHODS: The cross-sectional sample was from two stroke centres in China. Questionnaires were administered to collect sociodemographic data, stroke knowledge, coping traits, family functioning and stigma. Hierarchical regression models and the moderated parallel mediation model were constructed to analyse influencing pathways. The study adhered to the strengthening the reporting of observational studies in epidemiology guideline. RESULTS: All 144 samples reported stigma symptoms with a moderate-to-high standardising score. The best hierarchical regression model explains 55.5% of the variance in stigma. The parallel mediation model indicated that negative and positive coping traits co-mediating the association of stroke knowledge and stigma. After adding the family functioning as a moderator, the moderated parallel mediation model was confirmed with adequate fit indices. CONCLUSION: Among the cognitive appraisal factors affecting stroke-related stigma, stroke knowledge reduces stigma by modifying coping traits, while poor family functioning may serve as an opposing moderator. Notably, when family support is insufficient, enhanced stroke knowledge might paradoxically exacerbate the stigma. RELEVANCE TO CLINICAL PRACTICE: This study contributes knowledge on transforming health education and emphasises the pivotal roles of clinical nursing practitioners. In similar global contexts, the study highlights integrating health education, psychological counselling and family support to advance systematic nursing practices. PATIENT OR PUBLIC CONTRIBUTION: None.

Research Progress in the Regulation of the ABA Signaling Pathway by E3 Ubiquitin Ligases in Plants.

E3 ubiquitin ligases (UBLs), as enzymes capable of specifically recognizing target proteins in the process of protein ubiquitination, play crucial roles in regulating responses to abiotic stresses such as drought, salt, and temperature. Abscisic acid (ABA), a plant endogenous hormone, is essential to regulating plant growth, development, disease resistance, and defense against abiotic stresses, and acts through a complex ABA signaling pathway. Hormone signaling transduction relies on protein regulation, and E3 ubiquitin ligases play important parts in regulating the ABA pathway. Therefore, this paper reviews the ubiquitin-proteasome-mediated protein degradation pathway, ABA-related signaling pathways, and the regulation of ABA-signaling-pathway-related genes by E3 ubiquitin ligases, aiming to provide references for further exploration of the relevant research on how plant E3 ubiquitin ligases regulate the ABA pathway.

Long-term conservation tillage increase cotton rhizosphere sequestration of soil organic carbon by changing specific microbial CO2 fixation pathways in coastal saline soil.

Coastal saline soil is an important reserve resource for arable land globally. Data from 10 years of continuous stubble return and subsoiling experiments have revealed that these two conservation tillage measures significantly improve cotton rhizosphere soil organic carbon sequestration in coastal saline soil. However, the contribution of microbial fixation of atmospheric carbon dioxide (CO2) has remained unclear. Here, metagenomics and metabolomics analyses were used to deeply explore the microbial CO2 fixation process in rhizosphere soil of coastal saline cotton fields under long-term stubble return and subsoiling. Metagenomics analysis showed that stubble return and subsoiling mainly optimized CO2 fixing microorganism (CFM) communities by increasing the abundance of Acidobacteria, Gemmatimonadetes, and Chloroflexi, and improving composition diversity. Conjoint metagenomics and metabolomics analyses investigated the effects of stubble return and subsoiling on the reverse tricarboxylic acid (rTCA) cycle. The conversion of citrate to oxaloacetate was inhibited in the citrate cleavage reaction of the rTCA cycle. More citrate was converted to acetyl-CoA, which enhanced the subsequent CO2 fixation process of acetyl-CoA conversion to pyruvate. In the rTCA cycle reductive carboxylation reaction from 2-oxoglutarate to isocitrate, synthesis of the oxalosuccinate intermediate product was inhibited, with strengthened CO2 fixation involving the direct conversion of 2-oxoglutarate to isocitrate. The collective results demonstrate that stubble return and subsoiling optimizes rhizosphere CFM communities by increasing microbial diversity, in turn increasing CO2 fixation by enhancing the utilization of rTCA and 3-hydroxypropionate/4-hydroxybutyrate cycles by CFMs. These events increase the microbial CO2 fixation in the cotton rhizosphere, thereby promoting the accumulation of microbial biomass, and ultimately improving rhizosphere soil organic carbon. This study clarifies the impact of conservation tillage measures on microbial CO2 fixation in cotton rhizosphere of coastal saline soil, and provides fundamental data for the improvement of carbon sequestration in saline soil in agricultural ecosystems.

Autonomic function may mediate the neuroprotection of remote ischemic postconditioning in stroke: A randomized controlled trial.

OBJECTIVES: To evaluate the effect of remote ischemic postconditioning (RIPostC) on the prognosis of acute ischemic stroke(AIS) patients and investigate the mediating role of autonomic function in the neuroprotection of RIPostC. MATERIALS AND METHODS: 132 AIS patients were randomized into two groups. Patients received four cycles of 5-min inflation to a pressure of 200 mmHg(i.e., RIPostC) or patients' diastolic BP(i.e., shame), followed by 5 min of deflation on healthy upper limbs once a day for 30 days. The main outcome was neurological outcome including the National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), and Barthel index(BI). The second outcome measure was autonomic function measured by heart rate variability(HRV). RESULTS: Compared with the baseline, the post-intervention NIHSS score was significantly reduced in both groups (P<0.001). NIHSS score was significantly lower in the control group than intervention group at day 7.[RIPostC:3(1,5) versus shame:2(1,4); P=0.030]. mRS scored lower in the intervention group compared with the control group at day 90 follow-up(RIPostC:0.5±2.0 versus shame:1.0±2.0;P=0.016). The goodness-of-fit test revealed a significant difference between the generalized estimating equation model of mRS and BI scores of uncontrolled-HRV and controlled-HRV(P<0.05, both). The results of bootstrap revealed a complete mediation effect of HRV between group on mRS[indirect effect: -0.267 (LLCI = -0.549, ULCI = -0.048), the direct effect: -0.443 (LLCI = -0.831, ULCI = 0.118)]. CONCLUSION: This is the first human-based study providing evidence for a mediation role of autonomic function between RIpostC and prognosis in AIS patients. It indicated that RIPostC could improve the neurological outcome of AIS patients. Autonomic function may play a mediating role in this association. TRIAL REGISTRATION: The clinical trials registration number for this study is NCT02777099 (ClinicalTrials.gov Identifier).

Reducing the incidence of stroke-associated pneumonia: an evidence-based practice.

BACKGROUND: Pulmonary infection is a frequent complication among stroke patients and adversely affects clinical outcomes, increases the length of hospitalization stay and costs, and aggravates the financial burden of the national medical health system. Early identification and management of high-risk patients are necessary and imperative to reduce the incidence of stroke-associated pneumonia (SAP). AIM: The evidence-based practice project evaluated the effectiveness of a standard care bundle intervention in preventing the occurrence of SAP. METHODS: The project was conducted in a neurology department of a teaching hospital. Given the variation in assessment and management standards, evidence-based practice (EBP) methodology was used to establish a process for quality improvement. A thorough literature search was conducted to identify evidence-based interventions to manage and prevent SAP. Thorough critiques of the literature and synthesis of the evidence were completed. A systematic management flow and care bundle interventions were established. The care bundle included interventions, such as the utilization of tools for SAP risk screening; dysphagia screening and rehabilitation; feeding modification, oral care, airway management, position management, and the nursing techniques of traditional Chinese medicine. RESULTS: A significant improvement was observed in preventing SAP in patients in the postimplementation group compared with those in the preimplementation group (14.0% vs. 37.2%, p = 0.025). In addition, significantly lower duration of hospitalization, lower rate of aspiration, and improvements in albumin and oral hygiene were found after the implementation of the care bundle. CONCLUSIONS: Evidence-based care bundles successfully empower nurses to reduce the incidence of SAP. The management flow of SAP prevention could be promoted to other units of the neurology department in the future. The results of the project reflect positively on the capacity to implement EBP in an acute care setting for stroke. The EBP methodology can be utilized to solve other clinical problems.

Molecular characterization, expression and interaction of MAPK, MAPKK and MAPKKK genes in upland cotton.

Mitogen-activated protein kinase (MAPK) signaling cascades, consisting of three types of sequentially phosphorylated kinases (MAPKKK, MAPKK, and MAPK), play vital roles in various processes including plant development and stress response. In this study, 52 GhMAPKs, 23 GhMAPKKs, and 166 GhMAPKKKs were identified in upland cotton. Chromosomal locations, gene duplication and structure, motifs, cis-regulatory elements, and protein subcellular localization were further analyzed. With the identified MAPK cascade genes in G. arboretum and G. raimondii, a syntenic diagram of three cotton species was constructed. The interactions of seven GhMAPK cascade genes were investigated. Two complete signaling modules were defined: The GhMEKK24/GhMEKK31-GhMAPKK9-GhMAPK10 and GhMEKK3/GhMEKK24/GhMEKK31-GhMAPKK16-GhMAPK10/GhMAPK11 cascades. Moreover, interaction networks and the interaction pairs were combined with their expression patterns and demonstrated that the network mediated by the MAPK signaling cascade participates in abiotic stress signaling. Our research provides a foundation for studying the molecular mechanism of the MAPK signaling pathway under abiotic stress.

Long noncoding RNA lncRNA354 functions as a competing endogenous RNA of miR160b to regulate ARF genes in response to salt stress in upland cotton.

Long non-coding RNAs (lncRNAs) play important roles in response to biotic and abiotic stress through acting as competing endogenous RNAs (ceRNAs) to decoy mature miRNAs. However, whether this mechanism is involved in cotton salt stress response remains unknown. We report the characterization of an endogenous lncRNA, lncRNA354, whose expression was reduced in salt-treated cotton and was localized at the nucleus and cytoplasm. Using endogenous target mimic (eTM) analysis, we predicted that lncRNA354 had a potential binding site for miR160b. Transient expression in tobacco demonstrated that lncRNA354 was a miR160b eTM and attenuated miR160b suppression of its target genes, including auxin response factors (ARFs). Silencing or overexpressing lncRNA354 affected the expression of miR160b and target ARFs. Silencing lncRNA354 and targets GhARF17/18 resulted in taller cotton plants and enhanced the resistant to salt stress. Overexpression of lncRNA354 and targets GhARF17/18 in Arabidopsis led to dwarf plants, decreased root dry weight and reduced salt tolerance. Our results show that the lncRNA354-miR160b effect on GhARF17/18 expression may modulate auxin signalling and thus affect growth. These results also shed new light on a mechanism of lncRNA-associated responses to salt stress.

Characterizing microring resonators using optical frequency domain reflectometry.

A novel, to the best of our knowledge, method to extract optical microring resonators' loss characteristics is proposed and demonstrated using optical frequency domain reflectometry (OFDR). Compared with the traditional optical transmission measurement method, the spatial-resolved backscattering optical signals obtained from the OFDR can clearly show the resonance mode's increased optical path length due to its circulation inside the resonator. By further processing the backscattered optical signals, loaded $Q$-factors of several resonators can be accurately determined. A calculation model is proposed to derive the resonance mode's intrinsic $Q$-factor from OFDR measurements of a series of loaded resonators.

Mitigation of salt stress response in upland cotton (Gossypium hirsutum) by exogenous melatonin.

As a pleiotropic signal molecule, melatonin is ubiquitous throughout the animal and plant kingdoms and plays important roles in the regulation of plant growth, development, and responses to environmental stresses. In this study, we quantified the endogenous melatonin levels in upland cotton (Gossypium hirsutum L.), using high-performance liquid chromatography-tandem mass spectrometry. The melatonin concentrations in root, stem, and leaf were 150.60, 37.92, and 40.58 ng g fresh weight- 1, respectively. The effects of exogenous melatonin (1 µM) on plant growth, photosynthesis, antioxidant enzyme activity, and ion homeostasis in upland cotton seedlings exposed to 100 mM NaCl treatment were determined. Pretreatment (prior to exposure to salt stress) of seedlings with exogenous melatonin significantly alleviated plant growth inhibition by salt stress and maintained an improved photosynthetic capacity. The application of melatonin also significantly reduced the salt-induced oxidative damage, possibly through the accumulation of osmotic regulatory substances and the activation of antioxidant enzymes. We also showed that exogenous melatonin regulated the expression of stress-responsive and ion-channel genes under salinity, which could contribute to improved salt tolerance in cotton. Taken together, our study provides evidence that cotton contains endogenous melatonin, and it may have unraveled crucial evidence of the role of melatonin in cotton against salt stress.

Comprehensive analysis of the Gossypium hirsutum L. respiratory burst oxidase homolog (Ghrboh) gene family.

BACKGROUND: Plant NADPH oxidase (NOX), also known as respiratory burst oxidase homolog (rboh), encoded by the rboh gene, is a key enzyme in the reactive oxygen species (ROS) metabolic network. It catalyzes the formation of the superoxide anion (O2•-), a type of ROS. In recent years, various studies had shown that members of the plant rboh gene family were involved in plant growth and developmental processes as well as in biotic and abiotic stress responses, but little is known about its functional role in upland cotton. RESULTS: In the present study, 26 putative Ghrboh genes were identified and characterized. They were phylogenetically classified into six subfamilies and distributed at different densities across 18 of the 26 chromosomes or scaffolds. Their exon-intron structures, conserved domains, synteny and collinearity, gene family evolution, regulation mediated by cis-acting elements and microRNAs (miRNAs) were predicted and analyzed. Additionally, expression profiles of Ghrboh gene family were analyzed in different tissues/organs and at different developmental stages and under different abiotic stresses, using RNA-Seq data and real-time PCR. These profiling studies indicated that the Ghrboh genes exhibited temporal and spatial specificity with respect to expression, and might play important roles in cotton development and in stress tolerance through modulating NOX-dependent ROS induction and other signaling pathways. CONCLUSIONS: This comprehensive analysis of the characteristics of the Ghrboh gene family determined features such as sequence, synteny and collinearity, phylogenetic and evolutionary relationship, expression patterns, and cis-element- and miRNA-mediated regulation of gene expression. Our results will provide valuable information to help with further gene cloning, evolutionary analysis, and biological function analysis of cotton rbohs.

Applications of Bacillus subtilis Spores in Biotechnology and Advanced Materials.

The bacterium Bacillus subtilis has long been an important subject for basic studies. However, this organism has also had industrial applications due to its easy genetic manipulation, favorable culturing characteristics for large-scale fermentation, superior capacity for protein secretion, and generally recognized as safe (GRAS) status. In addition, as the metabolically dormant form of B. subtilis, its spores have attracted great interest due to their extreme resistance to many environmental stresses, which makes spores a novel platform for a variety of applications. In this review, we summarize both conventional and emerging applications of B. subtilis spores, with a focus on how their unique characteristics have led to innovative applications in many areas of technology, including generation of stable and recyclable enzymes, synthetic biology, drug delivery, and material sciences. Ultimately, this review hopes to inspire the scientific community to leverage interdisciplinary approaches using spores to address global concerns about food shortages, environmental protection, and health care.

Impact of the systematic use of the volume-viscosity swallow test in patients with acute ischaemic stroke: a retrospective study.

BACKGROUND: Dysphagia is common after stroke. Patients with dysphagia have a higher risk of stroke-associated pneumonia (SAP) and poor outcomes. Early detection of dysphagia is necessary to identify and manage patients at high risk of aspiration. The aim of the study was to assess the impact of the systematic administration of the volume-viscosity swallow test (V-VST) in patients with acute ischaemic stroke. METHODS: This was a retrospective observational study that enrolled patients with acute ischaemic stroke in two consecutive time periods: pre-V-VST, when the 30-mL water-swallowing test (WST) was systematically administered, and V-VST, when all patients underwent the WST and the V-VST test was systematically administered if the patient failed the WST. RESULTS: Two hundred and 42 patients were enrolled. The mean age of the participants was 68.8 ± 10.88 years, 61.2% were male, and the median National Institutes of Health Stroke Scale score was 3 (IQR, 1-6). A total of 147 patients were enrolled during the pre-V-VST period and 95 were enrolled during the V-VST period. There was a significant difference in the occurrence of SAP (21.8% vs. 10.5%, p = 0.024) and the rate of nasogastric tube feeding (25.9% vs. 14.7%, p = 0.040) between the two groups, and no differences were found in the length of hospital stay (p = 0.277) or the total cost of hospitalization (p = 0.846). CONCLUSIONS: The V-VST was a better clinical screening tool, and it can also provide detailed suggestions regarding dietary modifications to prevent aspiration and SAP.

Factors influencing health behaviour, blood pressure control, and disability in hypertensive ischaemic stroke patients after a comprehensive reminder intervention.

AIMS: To test prospective pathways of a Comprehensive Reminder System based on the Health Belief Model (CRS-HBM), stroke knowledge, health belief in health behaviour, blood pressure (BP) control, and disability in hypertensive ischaemic stroke patients at 6-month postdischarge. DESIGN: A nested cohort study design. METHODS: Data were derived from a randomized controlled trial evaluating the effects of the intervention (N = 174, performed during February 2015 - March 2016). Data were collected by questionnaires and analysed in structural equation modelling in Mplus software. RESULTS: The proposed model provided a good fit to the data. This model accounted for 51.5% of the variance in health behaviour, 34.1% in BP control, and 5.7% in modified Rankin Scale score at 6-month postdischarge. The CRS-HBM had: (a) direct positive effect (ß = .391, p < .001) and indirect positive effects (ß = .186, p = .002) on health behaviour; (b) direct positive effect (ß = .356, p < .001) and indirect positive effects (ß = .183, p = .009) on BP control; and (c) indirect negative effect (ß = -.146, p = .008) on disability. Being female was linked to better health behaviour. Higher education predicted higher level of stroke knowledge and health belief. CONCLUSIONS: The CRS-HBM can not only directly but also indirectly improve patients' health behaviours by improving their health knowledge or health belief. Better health behaviour can improve patients' BP control and reduce disability. Therefore, nurses need to pay more attention to not only patients' health knowledge but also their health belief when providing education. IMPACT: The CRS-HBM intervention accounted for 51.5% of variance in health behaviour, 34.1% in BP control, and 5.7% in modified Rankin Scale score at 6-month postdischarge. This research can help nurses improve health education strategies in postdischarge and community contexts to achieve better health results.

The long non-coding RNA lncRNA973 is involved in cotton response to salt stress.

BACKGROUND: Long non-coding (lnc) RNAs are a class of functional RNA molecules greater than 200 nucleotides in length, and lncRNAs play important roles in various biological regulatory processes and response to the biotic and abiotic stresses. LncRNAs associated with salt stress in cotton have been identified through RNA sequencing, but the function of lncRNAs has not been reported. We previously identified salt stress-related lncRNAs in cotton (Gossypium spp.), and discovered the salt-related lncRNA-lncRNA973. RESULTS: In this study, we identified the expression level, localization, function, and preliminary mechanism of action of lncRNA973. LncRNA973, which was localized in the nucleus, was expressed at a low level under nonstress conditions but can be significantly increased by salt treatments. Here lncRNA973 was transformed into Arabidopsis and overexpressed. Along with the increased expression compared with wild type under salt stress conditions in transgenic plants, the seed germination rate, fresh weights and root lengths of the transgenic plants increased. We also knocked down the expression of lncRNA973 using virus-induced gene silencing technology. The lncRNA973 knockdown plants wilted, and the leaves became yellowed and dropped under salt-stress conditions, indicating that the tolerance to salt stress had decreased compared with wild type. LncRNA973 may be involved in the regulation of reactive oxygen species-scavenging genes, transcription factors and genes involved in salt stress-related processes in response to cotton salt stress. CONCLUSIONS: LncRNA973 was localized in the nucleus and its expression was increased by salt treatment. The lncRNA973-overexpression lines had increased salt tolerance compared with the wild type, while the lncRNA973 knockdown plants had reduced salt tolerance. LncRNA973 regulated cotton responses to salt stress by modulating the expression of a series of salt stress-related genes. The data provides a basis for further studies on the mechanisms of lncRNA973-associated responses to salt stress in cotton.

Phase-coded Brillouin optical correlation domain analysis with 2-mm resolution based on phase-shift keying.

We report a phase-coded Brillouin optical correlation-domain analysis (BOCDA) based on phase-shift keying (PSK), in which the pseudo-random binary sequence (PRBS) phase coding is realized using a Mach-Zehnder modulator (MZM). Unlike the conventional phase-coded BOCDA using a phase modulator, which suffers from the non-rectangular transition in the encoded phase, the PSK can realize perfect phase switches between 0 and π with zero-width edges. It is not sensitive to the bandwidth of the modulator and the power of the radio-frequency modulation signal. Numerical simulations and experimental results prove that it can effectively suppress the Brillouin amplification in the off-peak positions. In experiment, a 2-mm spatial resolution sensing is realized using only a 20-GHz bandwidth MZM.

Ginsenoside Rh2 inhibits vascular endothelial growth factor-induced corneal neovascularization.

VEGF-induced neovascularization plays a pivotal role in corneal neovascularization (CoNV). The current study investigated the potential effect of ginsenoside Rh2 (GRh2) on neovascularization. In HUVECs, pretreatment with GRh2 largely attenuated VEGF-induced cell proliferation, migration, and vessel-like tube formation in vitro. At the molecular level, GRh2 disrupted VEGF-induced VEGF receptor 2 (VEGFR2)-Grb-2-associated binder 1 (Gab1) association in HUVECs, causing inactivation of downstream AKT and ERK signaling. Gab1 knockdown (by targeted short hairpin RNA) similarly inhibited HUVEC proliferation and migration. Notably, GRh2 was ineffective against VEGF in Gab1-silenced HUVECs. In a mouse cornea alkali burn model, GRh2 eyedrops inhibited alkali-induced neovascularization and inflammatory cell infiltrations in the cornea. Furthermore, alkali-induced corneal expression of mRNAs/long noncoding RNAs in cornea were largely attenuated by GRh2. Overall, GRh2 inhibits VEGF-induced angiogenic effect via inhibiting VEGFR2-Gab1 signaling in vitro. It also alleviates angiogenic and inflammatory responses in alkali burn-treated mouse corneas.-Zhang, X.-P., Li, K.-R., Yu, Q., Yao, M.-D., Ge, H.-M., Li, X.-M., Jiang, Q., Yao, J., Cao, C. Ginsenoside Rh2 inhibits vascular endothelial growth factor-induced corneal neovascularization.

MicroRNA414c affects salt tolerance of cotton by regulating reactive oxygen species metabolism under salinity stress.

Salinity stress is a major abiotic stress affecting the productivity and fiber quality of cotton. Although reactive oxygen species (ROS) play critical roles in plant stress responses, their complex molecular regulatory mechanism under salinity stress is largely unknown in cotton, especially microRNA (miRNA)-mediated regulation of superoxide dismutase gene expression. Here, we report that a cotton iron superoxide dismutase gene GhFSD1 and the cotton miRNA ghr-miR414c work together in response to salinity stress. The miRNA ghr-miR414c targets the coding sequence region of GhFSD1, inhibiting expression of transcripts of this antioxidase gene, which represents the first line of defense against stress-induced ROS. Expression of GhFSD1 was induced by salinity stress. Under salinity stress, ghr-miR414c showed expression patterns opposite to those of GhFSD1. Ectopic expression of GhFSD1 in Arabidopsis conferred salinity stress tolerance by improving primary root growth and biomass, whereas Arabidopsis constitutively expressing ghr-miR414c showed hypersensitivity to salinity stress. Silencing GhFSD1 in cotton caused an excessive hypersensitive phenotype to salinity stress, whereas overexpressing miR414c decreased the expression of GhFSD1 and increased sensitivity to salinity stress, yielding a phenotype similar to that of GhFSD1-silenced cotton. Taken together, our results demonstrated that ghr-miR414c was involved in regulation of plant response to salinity stress by targeting GhFSD1 transcripts. This study provides a new strategy and method for plant breeding in order to improve plant salinity tolerance.

Mechanisms and Functions of Long Non-Coding RNAs at Multiple Regulatory Levels.

Long non-coding (lnc) RNAs are non-coding RNAs longer than 200 nt. lncRNAs primarily interact with mRNA, DNA, protein, and miRNA and consequently regulate gene expression at the epigenetic, transcriptional, post-transcriptional, translational, and post-translational levels in a variety of ways. They play important roles in biological processes such as chromatin remodeling, transcriptional activation, transcriptional interference, RNA processing, and mRNA translation. lncRNAs have important functions in plant growth and development; biotic and abiotic stress responses; and in regulation of cell differentiation, the cell cycle, and the occurrence of many diseases in humans and animals. In this review, we summarize the functions and mechanisms of lncRNAs in plants, humans, and animals at different regulatory levels.

Identification of Gossypium hirsutum long non-coding RNAs (lncRNAs) under salt stress.

BACKGROUND: Long non-coding RNAs (lncRNAs) represent a class of riboregulators that either directly act in long form or are processed into shorter microRNAs (miRNAs) and small interfering RNAs. Long noncoding RNAs (lncRNAs) are arbitrarily defined as RNA genes larger than 200 nt in length that have no apparent coding potential. lncRNAs have emerged as playing important roles in various biological regulatory processes and are expressed in a more tissue-specific manner than mRNA. Emerging evidence shows that lncRNAs participate in stress-responsive regulation. RESULTS: In this study, in order to develop a comprehensive catalogue of lncRNAs in upland cotton under salt stress, we performed whole-transcriptome strand-specific RNA sequencing for three-leaf stage cotton seedlings treated with salt stress (S_NaCl) and controls (S_CK). In total we identified 1117 unique lncRNAs in this study and 44 differentially expressed RNAs were identified as potential non-coding RNAs. For the differentially expressed lncRNAs that were identified as intergenic lncRNAs (lincRNA), we analysed the gene ontology enrichment of cis targets and found that cis target protein-coding genes were mainly enriched in stress-related categories. Real-time quantitative PCR confirmed that all selected lincRNAs responsive to salt stress. We found lnc_388 was likely as regulator of Gh_A09G1182. And lnc_883 may participate in regulating tolerance to salt stress by modulating the expression of Gh_D03G0339 MS_channel. We then predicted the target mimics for miRNA in Gossypium. six miRNAs were identified, and the result of RT-qPCR with lncRNA and miRNA suggested that lnc_973 and lnc_253 may regulate the expression of ghr-miR399 and ghr-156e as a target mimic under salt stress. CONCLUSIONS: We identified 44 lincRNAs that were differentially expressed under salt stress. These lincRNAs may target protein-coding genes via cis-acting regulation. We also discovered that specifically-expressed lincRNAs under salt stress may act as endogenous target mimics for conserved miRNAs. These findings extend the current view on lincRNAs as ubiquitous regulators under stress stress.