Complete Stability of Delayed Recurrent Neural Networks With New Wave-Type Activation Functions.

Activation functions have a significant effect on the dynamics of neural networks (NNs). This study proposes new nonmonotonic wave-type activation functions and examines the complete stability of delayed recurrent NNs (DRNNs) with these activation functions. Using the geometrical properties of the wave-type activation function and subsequent iteration scheme, sufficient conditions are provided to ensure that a DRNN with n neurons has exactly (2m + 3)n equilibria, where (m + 2)n equilibria are locally exponentially stable, the remainder (2m + 3)n - (m + 2)n equilibria are unstable, and a positive integer m is related to wave-type activation functions. Furthermore, the DRNN with the proposed activation function is completely stable. Compared with the previous literature, the total number of equilibria and the stable equilibria significantly increase, thereby enhancing the memory storage capacity of DRNN. Finally, several examples are presented to demonstrate our proposed results.

A signal R3-type, CAPRICE-like MYB transcription factor from Dendrobium nobile controls trichome and root-hair development in Arabidopsis.

The CAPRICE-like MYB transcription factors with R3 MYB motif play a central role in regulating trichome and root-hair development in plants. We identified the homologous gene of ENHANCER OF TRY AND CPC (ETC) in Arabidopsis from Dendrobium nobile Lindl with full cDNA sequence and genomic sequence (CAPRICE-LIKE MYB, DnCPL and DngCPL) respectively. Phylogenic analyses revealed a close relationship of CAPRICE-like MYB TFs between D. nobile and A. thaliana. Promoter analysis indicated that DnCPL is specifically expressed in trichome basal cells of leaf epidermis and root hairs. Overexpression of DnCPL results in the suppression of trichome formation and overproduction of root hairs. In transgenic plants overexpressing DnCPL and DngCPL, trichome formation was inhibited, moreover, no trichomes were observed in tissues of aerial parts, and root-hair differentiation was significantly enhanced by strongly repressing endogenous genes of AtCPC, AtTCL1, and AtTCL2 expression, thereby enhancing AtTRY expression. The DnCPL RNAi plants formed fewer lateral roots with a corresponding change in AtCPC, AtTCL1 and AtTCL2 expression. These results suggest that Dendrobium and Arabidopsis partially use similar transcription factors for epidermal cell differentiation and the CPC-like R3 MYB, DnCPL, may be a key common regulator of plant trichome and root-hair development. The results also provided genes and means of regulation to improve the survival ratio of artificially cultivated Dendrobium with more lateral roots.

A Study of Strength Parameter Evolution and a Statistical Damage Constitutive Model of Cemented Sand and Gravel.

Cemented sand and gravel (CSG) has a wide range of applications in dam construction, and its properties are between rockfill and roller compacted concrete (RCC). A difference in gel content will result in a variance in CSG's structure and mechanical properties. To investigate the intricate structural mechanical properties of CSG, this study conducted a series of laboratory tests and associated discrete element analyses. Accordingly, the evolution law of the strength parameters of CSG is explored and a statistical damage constitutive model suitable for CSG is established. The main contributions of this study are as follows: (1) The failure mechanism of the CSG was described from the microscopic level, and the evolution law of the strength parameter cohesion and friction angle of the CSG was analyzed and summarized. (2) Based on the particle flow model, the energy development law and the spatiotemporal distribution law of acoustic emission (AE) provide illustrations of the strain hardening-softening transition features and the interaction between cohesion and friction of CSG. (3) The evolution function between the strength parameter and the strain softening parameter was built, and the critical strain softening parameter was determined by the microcrack evolution law of the particle flow model. (4) The accuracy of the evolution curve was confirmed by comparing it to experimental results. (5) Based on the relationship between cohesion loss and material damage, a statistical damage constitutive model was developed using the improved Mohr-Coulomb strength criterion as the micro strength function. The constitutive model can accurately describe the stress-strain curves of CSG with different gel content. Furthermore, the model reflects the strain hardening-softening properties of CSG and reveals the relationship between the weakening of cohesion and material damage at the microscopic level. These findings provide valuable guidelines for investigating the damage laws and microcosmic failure features of CSG and other relevant materials.

lncRNA NEAT1/miR-495-3p regulates angiogenesis in burn sepsis through the TGF-ß1 and SMAD signaling pathways.

INTRODUCTION: To investigate the role of the long-chain noncoding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) in the process of angiogenesis in human umbilical vein endothelial cells (HUVECs) and illustrate its potential role in burn sepsis (BS) pathogenesis. METHODS: HUVECs were treated with BS patient serum or healthy control serum. NEAT1 shRNA, miR-495-3p mimics, and miR-495-3p inhibitor were transfected into HUVECs. NEAT1 and miR-495-3 levels in serum or HUVECs were detected using quantitative reverse transcription-polymerase chain reaction. Cell counting kit-8 and flow cytometry assays were used to explore the proliferation and apoptosis of HUVECs. The expression of vascular endothelial growth factor (VEGF) in the supernatant was detected using enzyme-linked immunosorbent assay. Tube formation of HUVECs was also analyzed. Western blot analysis was used to analyze signaling pathway proteins. RESULTS: In HUVECs stimulated with BS patient serum, NEAT1 expression was increased, while miR-495-3p expression was decreased. In addition, NEAT1 silencing by specific shRNA inhibited cell proliferation, VEGF production, and tube formation under burn patient serum treatment, which decreased the TGFß1/SMAD signaling pathway activation. Moreover, miR-495-3p minics inhibited angiogenesis and the activation of signaling pathways induced by NEAT1 shRNA. Furthermore, miR-495-3p inhobitor promoted angiogenesis in HUVECs and activated the TGFß1/SMAD signaling pathway. In patients with BS, NEAT1 expression was significantly increased and miR-495-3p expression was decreased compared to healthy controls, and NEAT1 and miR-495-3p expression was associated with the clinical features of patients. CONCLUSIONS: Our results indicate that lncRNA NEAT1 regulates angiogenesis and activates the TGFß1/SMAD signaling pathway during the occurrence of BS.

Interval Bipartite Synchronization of Multiple Neural Networks in Signed Graphs.

Interval bipartite consensus of multiagents described by signed graphs has received extensive concern recently, and the rooted cycles play a critical role in stabilization, while the structurally balanced graphs are essential to achieve bipartite consensus. However, the gauge transformation used in the linear system is no longer feasible in the nonlinear case. This article addresses interval bipartite synchronization of multiple neural networks (NNs) in a signed graph via a Lyapunov-based approach, extending the existing work to a more practical but complicated case. A general matrix M in signed graphs is introduced to construct the novel Lyapunov functions, and sufficient conditions are obtained. We find that the rooted cycles and the structurally balanced graphs are essential to stabilize and achieve bipartite synchronization. More importantly, we discover that the nonrooted cycles are crucial in reaching interval bipartite synchronization, not previously mentioned. Several examples are presented to illustrate interval bipartite synchronization of multiple NNs with signed graphs.

The Event-Triggered Impulsive Controls for Quasisynchronization of the Leader-Following Heterogeneous Dynamical Networks.

The time-triggered impulsive controls were widely used to study the collective behavior of homogeneous dynamical networks due to their low control cost, which was a bit conservative in the occupation of communication channels. This article addresses designing the event-triggered impulsive controls for the quasisynchronization, namely, a weak cooperative behavior with the synchronization error no more than a positive constant in the leader-following heterogeneous dynamical network, which thus can reduce the occupation of resources significantly. The centralized and distributed impulsive controls are designed to lead the followers to synchronize approximately to the leader within a nonzero bound, where the impulsive instants are triggered, respectively, by the global or local state-dependent conditions. Numerical results are put forward to verify the effectiveness of the proposed methods.

Genome-wide transcriptome analysis of the orphan crop tef (Eragrostis tef (Zucc.) Trotter) under long-term low calcium stress.

Calcium (Ca2+) is one of the essential mineral nutrients for plant growth and development. However, the effects of long-term Ca2+ deficiency in orphan crops such as Tef [(Eragrostis tef) (Zucc.) Trotter], which accumulate high levels of Ca in the grains, remained unknown. Tef is a staple crop for nearly 70 million people in East Africa, particularly in Ethiopia and Eritrea. It is one of the most nutrient-dense grains, and is also more resistant to marginal soils and climatic conditions than main cereals like corn, wheat, and rice. In this study, tef plants were grown in a hydroponic solution containing optimum (1 mM) or low (0.01 mM) Ca2+, and plant growth parameters and whole-genome transcriptome were analyzed. Ca+2-deficient plants exhibited leaf necrosis, leaf curling, and growth stunting symptoms. Ca2+ deficiency significantly decreased root and shoot Ca, potassium (K), and copper content in both root and shoots. At the same time, it greatly increased root iron (Fe) content, suggesting the role of Ca2+ in the uptake and/or translocation of these minerals. Transcriptomic analysis using RNA-seq revealed that members of Ca2+ channels, including the cyclic nucleotide-gated channels and glutamate receptor-like channels, Ca2+-transporters, Ca2+-binding proteins and Ca2+-dependent protein kinases were differentially regulated by Ca+2 treatment. Moreover, several Fe/metal transporters, including members of vacuolar Fe transporters, yellow stripe-like, natural resistance-associated macrophage protein, and oligo-peptide transporters, were differentially regulated between shoot and root in response to Ca2+ treatment. Taken together, our findings suggest that Ca2+ deficiency affects plant growth and mineral accumulation by regulating the transcriptomes of several transporters and signaling genes.

Analysis of miRNAs responsive to long-term calcium deficiency in tef (Eragrostis tef (Zucc.) Trotter).

MicroRNAs (miRNAs) play an important role in growth, development, stress resilience, and epigenetic modifications of plants. However, the effect of calcium (Ca2+) deficiency on miRNA expression in the orphan crop tef (Eragrostis tef) remains unknown. In this study, we analyzed expression of miRNAs in roots and shoots of tef in response to Ca2+ treatment. miRNA-seq followed by bioinformatic analysis allowed us to identify a large number of small RNAs (sRNAs) ranging from 17 to 35 nt in length. A total of 1380 miRNAs were identified in tef experiencing long-term Ca2+ deficiency while 1495 miRNAs were detected in control plants. Among the miRNAs identified in this study, 161 miRNAs were similar with those previously characterized in other plant species and 348 miRNAs were novel, while the remaining miRNAs were uncharacterized. Putative target genes and their functions were predicted for all the known and novel miRNAs that we identified. Based on gene ontology (GO) analysis, the predicted target genes are known to have various biological and molecular functions including calcium uptake and transport. Pairwise comparison of differentially expressed miRNAs revealed that some miRNAs were specifically enriched in roots or shoots of low Ca2+-treated plants. Further characterization of the miRNAs and their targets identified in this study may help in understanding Ca2+ deficiency responses in tef and related orphan crops.

Quasisynchronization of Heterogeneous Dynamical Networks via Event-Triggered Impulsive Controls.

The time-triggered impulsive control of complex homogeneous dynamical networks has received wide attention due to its occasional occupation of the communication channels. This article is devoted to quasisynchronization of heterogeneous dynamical networks via event-triggered impulsive controls with less channel occupation. Two kinds of triggered mechanisms, that is, the centralized event-triggered mechanism in which the control is updated based upon the state information of all nodes, and the distributed event-triggered mechanism where the control is updated according to the state information of each node and its neighboring node, are proposed, respectively, such that the synchronization error between the heterogeneous dynamical networks and a virtual target is not more than a nonzero bound. What is more, the Zeno behavior is shown to be excluded. It is found that the combination method of the event-triggered control and the impulsive control, that is, the distributed event-triggered impulsive control has the advantage of low-energy consumption and takes up many fewer communication channels over the time-triggered impulsive control. Two numerical examples are conducted to illustrate the effectiveness of the proposed event-triggered impulsive controls.

Seasonal Variation in Transcriptomic Profiling of Tetrastigma hemsleyanum Fully Developed Tuberous Roots Enriches Candidate Genes in Essential Metabolic Pathways and Phytohormone Signaling.

Tetrastigma hemsleyanum Diels et Gilg (Sanyeqing, SYQ) is a perennial climbing liana and an endemic plant to southern China. Its tuberous roots (TRs) are used in traditional Chinese medicine for treating some diseases such as high fever, pneumonia, asthma, hepatitis, and cancers. However, the mechanisms underlying the development of TR and the content of flavonoids and phenylpropanoids (FPs) are not well-understood. In this study, we performed a transcriptomic analysis of 12 fully developed TR (FD-TR) samples harvested in four seasons [spring (Sp), summer (Su), autumn (Au), and winter (Wi)] using the RNA-Sequencing (RNA-Seq). We obtained a total of 78.54 Gb raw data and 65,578 unigenes. Then, the unigenes were annotated by using six databases such as non-redundant protein database (NR), Pfam, eggNOG, SWISSProt, Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene ontology (GO). The transcriptomic profiling showed closer relationships between the samples obtained in Su and Au than those obtained in Sp and Wi based on the results of both total unigenes and differentially expressed genes (DEGs). Three pathways, including the biosynthesis of FPs, metabolism of starch and sucrose, and signaling of phytohormones, were highly enriched, suggesting a gene-level seasonal variation. Based on the numbers of DEGs, brassinosteroid (BR) signal transduction factors appeared to play a key role in modulating the development of TRs while most of the auxin signaling genes were mainly activated in Wi and Sp FD-TRs. Most genes in the biosynthesis and biodegradation of starch and biodegradation of cellulose were activated in Wi FD-TRs. As determined by the high performance liquid chromatography (HPLC) and aluminum nitrate colorimetric method, the contents of total flavonoids and most detected FP components increased from Sp to Au but decreased in Wi. Enhanced expression levels of some genes in the biosynthetic pathways of FPs were detected in Su and Au samples, which corroborated well with metabolite content. Our findings provide the first transcriptomic and biochemical data on a seasonal variation in the composition of medically important metabolites in SYQ FD-TRs.

Silicon Enhances Biomass and Grain Yield in an Ancient Crop Tef [Eragrostis tef (Zucc.) Trotter].

Silicon (Si) is one of the beneficial plant mineral nutrients which is known to improve biotic and abiotic stress resilience and productivity in several crops. However, its beneficial role in underutilized or "orphan" crop such as tef [Eragrostis tef (Zucc.) Trotter] has never been studied before. In this study, we investigated the effect of Si application on tef plant performance. Plants were grown in soil with or without exogenous application of Na2SiO3 (0, 1.0, 2.0, 3.0, 4.0, and 5.0 mM), and biomass and grain yield, mineral content, chlorophyll content, plant height, and expression patterns of putative Si transporter genes were studied. Silicon application significantly increased grain yield (100%) at 3.0 mM Si, and aboveground biomass yield by 45% at 5.0 mM Si, while it had no effect on plant height. The observed increase in grain yield appears to be due to enhanced stress resilience and increased total chlorophyll content. Increasing the level of Si increased shoot Si and Na content while it significantly decreased the content of other minerals including K, Ca, Mg, P, S, Fe, and Mn in the shoot, which is likely due to the use of Na containing Si amendment. A slight decrease in grain Ca, P, S, and Mn was also observed with increasing Si treatment. The increase in Si content with increasing Si levels prompted us to analyze the expression of Si transporter genes. The tef genome contains seven putative Si transporters which showed high homology with influx and efflux Lsi transporters reported in various plant species including rice. The tef Lsi homologs were deferentially expressed between tissues (roots, leaves, nodes, and inflorescences) and in response to Si, suggesting that they may play a role in Si uptake and/or translocation. Taken together, these results show that Si application improves stress resilience and yield and regulates the expression of putative Si transporter genes. However, further study is needed to determine the physiological function of the putative Si transporters, and to study the effect of field application of Si on tef productivity.

Transcriptional Profiles of SmWRKY Family Genes and Their Putative Roles in the Biosynthesis of Tanshinone and Phenolic Acids in Salvia miltiorrhiza.

Salvia miltiorrhiza Bunge is a Chinese traditional herb for treating cardiovascular and cerebrovascular diseases, and tanshinones and phenolic acids are the dominated medicinal and secondary metabolism constituents of this plant. WRKY transcription factors (TFs) can function as regulators of secondary metabolites biosynthesis in many plants. However, studies on the WRKY that regulate tanshinones and phenolics biosynthesis are limited. In this study, 69 SmWRKYs were identified in the transcriptome database of S. miltiorrhiza, and phylogenetic analysis indicated that some SmWRKYs had closer genetic relationships with other plant WRKYs, which were involved in secondary metabolism. Hairy roots of S. miltiorrhiza were treated by methyl jasmonate (MeJA) to detect the dynamic change trend of SmWRKY, biosynthetic genes, and medicinal ingredients accumulation. Base on those date, a correlation analysis using Pearson's correlation coefficient was performed to construct gene-to-metabolite network and identify 9 SmWRKYs (SmWRKY1, 7, 19, 29, 45, 52, 56, 58, and 68), which were most likely to be involved in tanshinones and phenolic acids biosynthesis. Taken together, this study has provided a significant resource that could be used for further research on SmWRKY in S. miltiorrhiza and especially could be used as a cue for further investigating SmWRKY functions in secondary metabolite accumulation.

[Teaching research of Molecular Pharmacognosy for talent development in industry of Chinese medicinal materials under new situation].

The industry of Chinese medicinal materials is going through another high-level development stage with some important files issued by Chinese government in the past months, such as "the protection and development plans of Chinese medicinal materials (2015-2020)" and "the strategic development plans of Chinese medicine (2016-2030)". In addition, the effect of "TU Youyou" will not only improve the industry development, but also indicates the increasing international competition intensely. Therefore, one of the core problems of the sustainable-development industry is the training of senior talents under the "New Situation" with opportunity and intense competition. As one of the forefront courses of Chinese Pharmacology, Molecular Pharmacognosy (MP) is a new interdisciplinary science, which integrates the pharmacognosy and molecular biology, and combines many discipline theories and technological systems. MP not only inherits the traditional concepts,but also makes up for the shortages of pharmacognosy, and improves the development of pharmacognosy. Thus, these are importance of MP for cultivation of senior talents, and also the difficult teaching points of MP with no unified teaching mode. We will, in this paper, discuss the possible teaching modes through several aspects for talent cultivation and meeting the needs of social and industry development, such as teaching state of MP, the education of undergraduate and graduate students, social identity, and self renewal of curriculum theories and practice.

Characterization of Salinity Tolerance of Transgenic Rice Lines Harboring HsCBL8 of Wild Barley (Hordeum spontanum) Line from Qinghai-Tibet Plateau.

Rice is more sensitive to salinity, particularly at its early vegetative and later productive stages. Wild plants growing in harsh environments such as wild barley from Qinghai-Tibet Plateau adapt to the adverse environment with allelic variations at the loci responsible for stressful environment, which could be used for rice genetic improvement. In this study, we overexpressed HsCBL8 encoding a calcium-sensor calcineurin B-like (CBL) protein in rice. The gene was isolated from XZ166, a wild-barley (Hordeum spontanum) line originated from Qinghai-Tibet Plateau. We found that XZ166 responded to high NaCl concentration (200 mM) with more HsCBL8 transcripts than CM72, a cultivated barley line known for salinity tolerance. XZ166 is significantly different from CM72 with nucleotide sequences at HsCBL8. The overexpression of HsCBL8 in rice resulted in significant improvement of water protection in vivo and plasma membrane, more proline accumulation, and a reduction of overall Na+ uptake but little change in K+ concentration in the plant tissues. Notably, HsCBL8 did not act on some genes downstream of the rice CBL family genes, suggesting an interesting interaction between HsCBL8 and unknown factors to be further investigated.

Leader-following consensus of the second-order multi-agent systems under directed topology.

This paper investigates the consensus problem for second-order multi-agent systems with a dynamical leader. A simple and novel protocol based on the relative state of the neighboring agents is proposed. Using the linear matrix inequality method, sufficient conditions are derived to ensure the consensus for both the cases without and with communication delay in the multi-agent systems. Some numerical simulations are also given to show the effectiveness of the proposed results.

[Clinical study on application of intermittent hemofiltration combined with hemoperfusion in the early stage of severe burn in the prevention and treatment of sepsis].

OBJECTIVE: To investigate the effects of application of intermittent hemofiltration combined with hemoperfusion (HP) in the early stage of severe burn in the prevention and treatment of sepsis. METHODS: Forty severely burned patients, admitted to our burn ward from June 2011 to March 2013, conforming to the study criteria, were divided into conventional treatment group (CT, n=20) and blood purification group (BP, n=20) according to the random number table. Patients in group CT received CT according to the accepted principles of treatment for a severe burn. Patients in group BP received CT and intermittent hemofiltration combined with HP once respectively on post injury day (PID) 3, 5, and 7, spanning 6 to 8 hours for each treatment. On PID 3, 5, 7, 10, and 14, body temperature, heart rate, and respiratory rate were recorded; white blood cell count (WBC), neutrophil granulocytes, blood urea nitrogen (BUN), and creatinine were determined; levels of IL-1, IL-6, TNF-α, and high-mobility group box 1 (HMGB1) in serum were determined by ELISA; level of LPS in serum was determined with the chromogenic substrate limulus amebocyte lysate method; level of procalcitonin (PCT) in serum was determined by double antibody sandwich immune chemiluminescence method. The symptoms and signs of sepsis were observed during the treatment. Data were processed with Fisher's exact test, chi-square test, analysis of variance for repeated measurement, and LSD-t test. RESULTS: (1) Except for that on PID 5, the mean body temperature of patients in group BP was significantly lower than that of group CT at each of the rest time points (with t values from 1.87 to 2.97, P values below 0.05). The heart rate was significantly slower in patients of group BP than in group CT from PID 3 to 14 (with t values from 1.78 to 3.59, P values below 0.05). Except for that on PID 3, the respiratory rate of patients in group BP was significantly slower than that of group CT at each of the rest time points (with t values from 1.93 to 2.85, P values below 0.05). (2) The levels of WBC, neutrophil granulocytes, BUN, and creatinine of patients in group BP were significantly lower than those of group CT (with t values from 1.78 to 4.23, P values below 0.05). (3) Except for that on PID 3, the level of IL-1 of patients in group BP was significantly lower than that of group CT at each of the rest time points (with t values from 1.97 to 4.16, P values below 0.05). Except for that on PID 7, the level of IL-6 of patients in group BP was significantly lower than that of group CT at each of the rest time points (with t values from 2.11 to 6.34, P values below 0.05). The levels of TNF-α and HMGB1 of patients in group BP were significantly lower than those of group CT from PID 3 to 14 (with t values from 1.98 to 5.29, P values below 0.05). (4) On PID 3, 5, 7, 10, and 14, the levels of LPS and PCT of patients in group BP were respectively (0.23 ± 0.07), (0.27 ± 0.09), (0.22 ± 0.06), (0.20 ± 0.08), (0.15 ± 0.07) EU/mL, and (0.44 ± 0.12), (0.67 ± 0.13), (0.74 ± 0.13), (0.64 ± 0.12), (0.71 ± 0.10) ng/mL, and they were lower than those of group CT [(0.37 ± 0.08), (0.45 ± 0.09), (0.56 ± 0.09), (0.48 ± 0.08), (0.40 ± 0.08) EU/mL, and (0.74 ± 0.11), (1.16 ± 0.12), (1.40 ± 0.13), (1.55 ± 0.15), (1.49 ± 0.14) ng/mL, with t values from 1.88 to 3.43, P values below 0.05]. (5) The incidence of sepsis of patients in group BP was obviously lower than that of group CT (χ² = 6.94, P<0.01). CONCLUSIONS: Intermittent hemofiltration combined with HP can effectively improve blood biochemical indexes and vital signs and reduce the occurrence of burn sepsis by decreasing the levels of proinflammatory cytokines, LPS, and PCT.

Nitric Oxide Plays a Central Role in Water Stress-Induced Tanshinone Production in Salvia miltiorrhiza Hairy Roots.

Nitric oxide (NO), a well-known signaling molecule plays an important role in abiotic and biotic stress-induced production of plant secondary metabolites. In this study, roles of NO in water stress-induced tanshinone production in Salvia miltiorrhiza hairy roots were investigated. The results showed that accumulations of four tanshinone compounds in S. miltiorrhiza hairy roots were significantly stimulated by sodium nitroprusside (SNP, a NO donor) at 100 µM. Effects of SNP were just partially arrested by the mevalonate (MVA) pathway inhibitor (mevinolin), but were completely inhibited by the 2-C-methyl-d-erythritol-4-phosphate pathway (MEP) inhibitor (fosmidomycin). The increase of tanshinone accumulation and the up-regulation of HMGR and DXR expression by PEG and ABA treatments were partially inhibited by an inhibitor of NO biosynthesis (Nω-nitro-L-arginine methyl ester (L-NAME)) and a NO scavenger (2-(4-Carboxyphenyl)- 4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO)). Simultaneously, NO generation in the hairy roots was triggered by PEG and ABA, and the effects were also arrested by c-PTIO and L-NAME. These results indicated that NO signaling probably plays a central role in water stress-induced tanshinone production in S. miltiorrhiza hairy roots. SNP mainly stimulated the MEP pathway to increase tanshinone accumulation.

Magnesium stress signaling in plant: just a beginning.

Magnesium (Mg) is one of the most important nutrients, involves mainly in plant growth and development. However, the signaling pathways response to magnesium stresses (MgSs) is known little, but several studies lately may improve the research development. Several phytohormones such as abscisic acid (ABA), ethylene, auxins, and their factors were found responding to MgSs, and there may be some signal pathways linking these hormones and downstream reactions together, e.g., carbon fixation and transfer, starch and sugar metabolism, ion uptaking and reactive oxygen species (ROS) increasing. Consequently, Arabidopsis morphogenesis is remodeled. In this review, we mainly discussed recent literatures involving in plant response to MgSs (Mg deficiency (MgD) and Mg toxicity (MgT)), including plant morphogenesis remodeling, magnesium transporters and signaling transductions. Moreover, the future study challenges related to the responding signalings to MgSs in plants are also presented. Regardless, the iceberg of signal transduction of MgSs in plants is appeared.

Ag+ as a more effective elicitor for production of tanshinones than phenolic acids in Salvia miltiorrhiza hairy roots.

Phenolic acids and tanshinones are two groups of bioactive ingredients in Salvia miltiorrhiza Bunge. As a heavy metal elicitor, it has been reported that Ag+ can induce accumulations of both phenolic acids and tanshinones in S. miltiorrhiza hairy roots. In this study, the effects of Ag+ treatment on accumulations of six phenolic acids and four tanshinones in S. miltiorrhiza hairy roots were investigated. To further elucidate the molecular mechanism, expressions of key genes involved in the biosynthesis of these ingredients were also detected. The results showed that although the total phenolic acids content was almost not affected by Ag+, accumulations of rosmarinic acid (RA), caffeic acid and ferulic acid were significantly increased, while accumulations of salvianolic acid B (LAB), danshensu (DSU) and cinnamic acid were decreased. We speculate that LAB probably derived from the branch pathway of DSU biosynthesis. Contents of four tanshinones were enhanced by Ag+ and their accumulations were more sensitive to Ag+ than phenolic acids. Genes in the upstream biosynthetic pathways of these ingredients responded to Ag+ earlier than those in the downstream biosynthetic pathways. Ag+ probably induced the whole pathways, upregulated gene expressions from the upstream pathways to the downstream pathways, and finally resulted in the enhancement of ingredient production. Compared with phenolic acids, tanshinone production was more sensitive to Ag+ treatments. This study will help us understand how secondary metabolism in S. miltiorrhiza responds to elicitors and provide a reference for the improvement of the production of targeted compounds in the near future.

The remodeling of seedling development in response to long-term magnesium toxicity and regulation by ABA-DELLA signaling in Arabidopsis.

Little information is available about signaling response to magnesium toxicity (MgT) in plants. This study presents the first evidence that abscisic acid (ABA) and DELLA proteins participate in signaling response to long-term MgT in Arabidopsis thaliana (Landsberg erecta). Morphological, physiological, and molecular characteristics of a wild-type and two Arabidopsis mutants, ABA-insensitive mutant abi1-1 and constitutive elevated GA response mutant quadruple-DELLA (DELLA-Q: gai-t6 rga-t2 rgl1-1 rgl2-1) were monitored under MgT and normal magnesium conditions. Two weeks of MgT treatment strongly influenced the growth of young plants, but growth inhibition of the DELLA-Q and abi1-1 mutants was less than that of the wild-type plants. Exogenous ABA further inhibited the growth of the DELLA-Q mutants, similar to that of the wild-type. Both ABA and MgT also promoted DELLA protein RGA accumulation in the nuclei. Transcriptional analysis supported these results and revealed that a complex signaling network has responded to MgT in Arabidopsis. DELLA enhancement, which depends on ABI1, contributed to the remodeling growth and development of young seedlings.