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Abscisic acid–inducible NAC32 alleviates magnesium toxicity-mediated cell death in roots through direct regulation of XIPOTL1 expression in Arabidopsis.

As one of the components of root exudates, methyl 3-(4-hydroxyphenyl) propionate (MHPP) not only functions as a nitrification inhibitor in soil but also modulates plant growth and root system architecture (RSA); however, the physiological and molecular mechanisms underlying MHPP-mediated plant growth remain largely unclear. Here, we investigated the effects of MHPP treatment on growth and secondary metabolite accumulation by integrating physiology, transcriptome and metabolome analyses using perilla (Perilla frutescens), a type of medicinal and edible plant. MHPP reduces primary root growth but markedly induces lateral root formation in perilla seedlings. The full-length transcript sequencing combined with the comparative transcriptomic analysis revealed that the differential expression of genes involved in carbon/nitrogen metabolism and secondary metabolism contributed to the MHPP-mediated plant growth. An investigation of the differentially expressed genes showed that MHPP modulates the growth and metabolism of leaves and roots in distinct pathways. The genes involved in the phenylpropanoid metabolism pathway showed opposite expression patterns between the roots and leaves, thereby resulting in the differential accumulation of secondary metabolites in the roots and leaves. Furthermore, the differential expression of PER genes and elevated peroxidase activity in the MHPP-treated roots were responsible for modulating the equilibrium of ROS and the components of lignin and phenolic compounds, thereby affecting plant growth and secondary metabolite accumulation. MHPP modulates RSA and metabolite profiles and improves the contents of medicinal ingredients in perilla plants. These results suggested that the application of MHPP may represent a useful strategy for the medicinal plant cultivation.

Carbon-based nanomaterials have potential applications in nanoenabled agriculture. However, the physiological and molecular mechanisms underlying single-walled carbon nanohorn (SWCNH)-mediated plant growth remain unclear. Here, we investigated the effects of SWCNHs on Arabidopsis grown in 1/4-strength Murashige and Skoog medium via physiological, genetic, and molecular analyses. Treatment with 0.1 mg/L SWCNHs promoted primary root (PR) growth and lateral root (LR) formation; 50 and 100 mg/L SWCNHs inhibited PR growth. Treatment with 0.1 mg/L SWCNHs increased the lengths of the meristematic and elongation zones, and transcriptomic and genetic analyses confirmed the positive effects of SWCNHs on root tip stem cell niche activity and meristematic cell division potential. Increased expression of YUC3 and YUC5 and increased PIN2 abundance improved PR growth and LR development in 0.1 mg/L SWCNH-treated seedlings. Metabolomic analyses revealed that SWCNHs altered the levels of sugars, amino acids, and organic acids, suggesting that SWCNHs reprogrammed carbon/nitrogen metabolism in plants. SWCNHs also regulate plant growth and development by increasing the levels of several secondary metabolites; transcriptomic analyses further supported these results. The present results are valuable for continued use of SWCNHs in agri-nanotechnology, and these molecular approaches could serve as examples for studies on the effects of nanomaterials in plants.

With the increasing use of zinc oxide nanoparticles (ZnO NPs) in industry, there is an increased release of these NPs into ecosystem, with potential impact on the ecological environment. Herein, we investigated the physiological and molecular mechanisms underlying ZnO NP-mediated plant growth in tomato plants. Foliar spraying with ZnO NPs (20 and 100 mg L−1) improved tomato growth by increasing the chlorophyll content and photosystem II activity. Comparative transcriptomic analysis revealed that ZnO NPs upregulated the expression of a set of genes involved in nutrient element transport, carbon/nitrogen metabolism, and the secondary metabolism in tomato, with the metabolome analysis further supporting this result. Foliar spraying with ZnO NPs increased iron (Fe) accumulation by 12.2% in tomato leaves; we thus examined the effects of ZnO NPs in tomato plants in response to Fe deficiency. Interestingly, foliar spraying with ZnO NPs markedly improved Fe deficiency tolerance in tomato. Physiological analysis indicated that ZnO NPs reduced Fe deficiency-induced oxidative damage and improved the metal nutrient element contents in tomato. Further, transcriptomic and metabolomic analyses indicated that foliar spraying with ZnO NPs increased the expression of genes encoding antioxidative enzymes, transporters, and the enzymes or regulators involved in carbon/nitrogen metabolism and secondary metabolism, thereby improving the levels of antioxidation, sugars, and amino acids in Fe-deficient tomato plants. Taken together, these results contribute to our understanding of the ecological effects of ZnO NPs.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most representative perfluoroalkyl substances that accumulate in the food chain and are harmful to the environment. The uptake, translocation and physiological effects of PFOA and PFOS in plants have been reported in recent years; however, the regulatory mechanisms underlying PFOA- and PFOS-mediated plant growth and development remain largely unclear. Here, using Arabidopsis thaliana as the study material, we showed that both PFOA and PFOS inhibited plant growth; PFOS showed a stronger inhibitory effect on primary root (PR) growth, whereas PFOA exerted a stronger inhibitory effect on photosynthesis. Transcriptome analysis revealed that PFOA- and PFOS-modulated plant growth and development were correlated with the phytohormones auxin and abscisic acid (ABA). Further genetic analyses using mutants related to auxin biosynthesis, receptors and transport and mutants related to ABA biosynthesis and signalling transduction revealed that both PFOA and PFOS inhibited PR growth by modulating auxin biosynthesis and signalling pathways, and the ABA signalling pathway was also involved in PFOS-mediated PR growth inhibition. Collectively, these results shed new light on the molecular mechanisms of PFOA- and PFOS-mediated root system growth and their effects on phytohormone signalling pathways in plants.

Summary Crosstalk among ABA, auxin, and ROS plays critical roles in modulating seed germination, root growth, and suberization. However, the underlying molecular mechanisms remain largely elusive. Here, MYB70, a R2R3-MYB transcription factor was shown to be a key component of these processes in Arabidopsis thaliana. myb70 seeds displayed decreased sensitivity, while MYB70-overexpressing OX70 seeds showed increased sensitivity in germination in response to exogenous ABA through MYB70 physical interaction with ABI5 protein, leading to enhanced stabilization of ABI5. Furthermore, MYB70 modulates root system development (RSA) which is associated with increased conjugated IAA content and H2O2/O2⋅− ratio but reduced root suberin deposition, consequently affecting nutrient uptake. In support of these data, MYB70 positively regulates the expression of auxin conjugation-related GH3, while negatively peroxidase-encoding and suberin biosynthesis-related genes. Our findings collectively revealed a previously uncharacterized component that modulates ABA and auxin signaling pathways, H2O2/O2⋅− balance, and suberization, consequently regulating RSA and seed germination., Graphical abstract, Highlights • MYB70 regulates seed germination by enhancing ABA signaling via interaction with ABI5 • MYB70 activates the IAA conjugation process by upregulating GH3 genes expression • MYB70 mediates root growth via repression of PER genes • MYB70 negatively regulates suberin biosynthesis in roots, Biological sciences; Cell biology; Plant biology; Plant histology; Plant Genetics

Abscisic acid (ABA) reduces accumulation of potentially toxic cadmium (Cd) in plants. How the ABA signal is transmitted to modulate Cd uptake remains largely unclear. Here, we report that the basic region/Leu zipper transcription factor ABSCISIC ACID-INSENSITIVE5 (ABI5), a central ABA signaling molecule, is involved in ABA-repressed Cd accumulation in plants by physically interacting with a previously uncharacterized R2R3-type MYB transcription factor, MYB49. Overexpression of the Cd-induced MYB49 gene in Arabidopsis (Arabidopsis thaliana) resulted in a significant increase in Cd accumulation, whereas myb49 knockout plants and plants expressing chimeric repressors of MYB49:ERF-associated amphiphilic repression motif repression domain (SRDX49) exhibited reduced accumulation of Cd. Further investigations revealed that MYB49 positively regulates the expression of the basic helix-loop-helix transcription factors bHLH38 and bHLH101 by directly binding to their promoters, leading to activation of IRON-REGULATED TRANSPORTER1, which encodes a metal transporter involved in Cd uptake. MYB49 also binds to the promoter regions of the heavy metal-associated isoprenylated plant proteins (HIPP22) and HIPP44, resulting in up-regulation of their expression and subsequent Cd accumulation. On the other hand, as a feedback mechanism to control Cd uptake and accumulation in plant cells, Cd-induced ABA up-regulates the expression of ABI5, whose protein product interacts with MYB49 and prevents its binding to the promoters of downstream genes, thereby reducing Cd accumulation. Our results provide new insights into the molecular feedback mechanisms underlying ABA signaling-controlled Cd uptake and accumulation in plants.

Studies have indicated that the carbon starvation response leads to the reprogramming of the transcriptome and metabolome, and many genes, including several important regulators, such as the group S1 basic leucine zipper transcription factors (TFs) bZIP1, bZIP11 and bZIP53, the SNAC-A TF ATAF1, etc., are involved in these physiological processes. Here, we show that the SNAC-A TF ANAC032 also plays important roles in this process. The overexpression of ANAC032 inhibits photosynthesis and induces reactive oxygen species accumulation in chloroplasts, thereby reducing sugar accumulation and resulting in carbon starvation. ANAC032 reprograms carbon and nitrogen metabolism by increasing sugar and amino acid catabolism in plants. The ChIP-qPCR and transient dual-luciferase reporter assays indicated that ANAC032 regulates trehalose metabolism via the direct regulation of TRE1 expression. Taken together, these results show that ANAC032 is an important regulator of the carbon/energy status that represses photosynthesis to induce carbon starvation.

To analyze the accuracy of implant position in simple cases by freehand.Ninety-seven implants of 68 patients from 3 surgeons were selected.After operation,the deviations of implant position at shoulder apex and angle were measured using cone-beam CT(CBCT).The mean of three parameters were calculated with SPSS 22.0 software package, and the differences were analyzed between three surgeons,three operation areas,free-end missing and non free-end missing.The deviations of 97 implants were (0.76±0.57)mm，(1.41±0.90)mm，(4.76±3.68)° at shoulder, apex and angle.The deviation of shoulder apex and angle between three surgeons was significantly different(P0.05). The deviations between left and right group were not significantly different (P0.05); the deviations between anterior group and left group were significantly different(P0.05); the deviations between anterior group and right group were not significantly different(P0.05). The deviation of shoulder between free-end missing area and non free-end missing area was significantly different(P0.05),other parameters between the two groups were not significantly different(P0.05).The deviation of implant placement between surgical guide and mental guide were similar in simple cases. The experience of surgeon was important during freehand implant placement. The deviations were lower when missing tooth is in anterior area than in posterior area, whereas the same at shoulder in non free-end missing area than in free-end missing area.

Carbon-based nanomaterials have potential applications in nanoenabled agriculture. However, the physiological and molecular mechanisms underlying single-walled carbon nanohorn (SWCNH)-mediated plant growth remain unclear. Here, we investigated the effects of SWCNHs on

To study the effect of quality control circle activity on improving nursing quality of patients with periodontitis.One hundred and twenty patients with periodontitis admitted to our hospital from January 2016 to December 2017 were selected and divided into experimental group and control group according to the principle of random control, with 60 patients in each group. Patients in both groups received supragingival scaling, subgingival scaling and related symptomatic treatment, patients in the experimental group conducted nursing under the guidance of quality control circle, while patients in the control group received routine nursing. Satisfaction degree, therapeutic effect and gingival index, probe depth, gingival sulcus bleeding index, plaque index and periodontal attachment levels were recorded and compared between the two groups using SPSS 19.0 software package.After quality control circle to guide nursing, the patients' satisfaction (P=0.003) and the total effective rate of treatment was significantly higher than the control group(P=0.002), the incidence of oral health problems in the experimental group was significantly lower than the control group(P=0.037), PD, GI, SBI, PLI and AL levels in the experimental group were significantly lower than the control group(P=0.000). In addition to the tangible achievements，intangible results, such as quality control circles harmonious degree of nursing, sense of responsibility, communication, and problem solving ability, cohesion and quality control methods are improved distinctly in the experimental group.Quality control circle activity can improve nursing quality of patients with periodontitis.

Zinc oxide (ZnO) nanoparticles (nZnO) are among the most commonly used nanoparticles (NPs), and they have been shown to have harmful effects on plants. However, the molecular mechanisms underlying nZnO tolerance and root sensing of NP stresses have not been elucidated. Here, we compared the differential toxic effects of nZnO and Zn

Background Melatonin and serotonin are well-known signaling molecules that mediate multiple physiological activities in plants, including stress defense, growth, development, and morphogenesis, but their underlying mechanisms have not yet been thoroughly elucidated. In this study, we investigated the roles of melatonin and serotonin in modulating plant growth and defense by integrating physiological and transcriptome analyses in Arabidopsis. Results Moderate concentrations of melatonin and serotonin did not affect primary root (PR) growth but markedly induced lateral root (LR) formation. Both melatonin and serotonin locally induced the expression of the cell-wall-remodeling-related genes LBD16 and XTR6, thereby inducing LR development. Our data support the idea that melatonin and serotonin lack any auxin-like activity. Treatment with 50 μM serotonin significantly improved PSII activity, and the transcriptome data supported this result. Melatonin and serotonin slightly affected glycolysis and the TCA cycle; however, they markedly regulated the catabolism of several key amino acids, thereby affecting carbon metabolism and energy metabolism. Melatonin and serotonin improved iron (Fe) deficiency tolerance by inducing Fe-responsive gene expression. Conclusions Overall, our results from the physiological and transcriptome analyses reveal the roles of melatonin and serotonin in modulating plant growth and stress responses and provide insight into novel crop production strategies using these two phytoneurotransmitters. Electronic supplementary material The online version of this article (10.1186/s12870-018-1548-2) contains supplementary material, which is available to authorized users.

The liver X receptors (LXRs) is an important component of the nuclear receptor (NR) superfamily. Previous studies have shown that the LXRs possessed antitumor activity in various types of tumor cells. However, the complicated mechanisms underlying the antitumor activity remain largely unexplored. In this study, we incubated A549 cells with the compound T0901317, a specific LXRs agonist, for 24 h. The MTT assay was used to assess cell viability. Transwell assays were used to evaluate cell migration and invasion. The shRNA was utilized for RNA interference. The target gene and protein expression levels were assessed using reverse transcription-PCR and western blot assay. The DNA-binding activity of nuclear factor κB (NF-κB) was examined using electrophoretic mobility shift assays. Luciferase reporter assay was used to detect the binding of NF-κB to the matrix metalloproteinase-9 (MMP-9) promoter. We found that T0901317 inhibited the invasion and migration of A549 cells in a dose-dependent manner. Meanwhile, we further indicated that activation of LXRβ, one subtype of LXRs, can downregulate MMP-9 expression. More importantly, activation of LXRβ triggered by T0901317 inhibited the invasion and metastasis of A549 cells by repressing NF-κB/MMP-9 signaling pathway. Taken together, our study shows that activation of LXRs triggered by T0901317 inhibits the invasion and metastasis of human non-small-cell lung cancer by repressing the NF-κB/MMP-9 signaling pathway.

The liver-X-receptors have shown anti-fibrosis ability in several animal models. Our purpose was to investigate the effect of LXRs in bleomycin induced lung fibrosis in mice. Bleomycin was intratracheally delivered to mice. Some mice were administered a LXR agonist, T0901317. Then mice were evaluated for the development of lung inflammation and fibrosis. T0901317 was able to attenuate the inflammation and fibrosis induced by bleomycin. T0901317 treatment evidently abolished the high level of TGF-β1 and inhibited NF-κB DNA-binding activity in lung. So LXRs may attenuate the progressing of lung fibrosis, providing a potential treatment of IPF.