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Objectives Materials and Methods Results Conclusions To investigate whether a labially inclined implant axis compromises the clinical outcomes of immediate implant placement and provisionalization (IIPP) in the anterior maxilla.Patients with unsalvageable central or lateral maxillary incisors were enrolled. IIPP with simultaneous connective tissue graft (CTG) was performed in all participants. In the control group, the alveolar ridge had a long axis aligned with the tooth, which ensured that the immediate implant was aimed at the incisor edge or the cingulum of future restoration. The test group had a large angle between the axes of the ridge and tooth. To avoid bone fenestration, the implants were placed labially inclined and emerged from the labial side of future restoration. Intra‐oral scanning and cone‐beam computed tomography were performed to record soft and hard tissue profiles at baseline and 1 year later. Soft tissue stability, bone remodeling, and pink esthetic score (PES) were evaluated and compared between two groups.Thirty‐nine participants (19 tests and 20 controls) completed the study. At 1‐year post‐surgery, the mid‐facial gingival margin migrations were 0.85 ± 0.37 mm (test) and 0.81 ± 0.33 mm (control), without significant differences. No differences were identified in buccal profile alteration, linear ridge reduction, buccal bone thickness, or PES scores. The test group demonstrated thinner buccal soft tissue at the crestal level than the control group.When large tooth‐ridge angulation presented, labially inclined implant, avoiding buccal ridge fenestration in IIPP with CTG, did not compromise the clinical outcome in short term. [ABSTRACT FROM AUTHOR]

Purpose: This is a clinical study to compare immediate and staged impression methods in a complete digital workflow for single‐unit implants in the posterior area. Materials and Methods: Sixty patients requiring single‐unit implant crowns were enrolled. Forty patients were assigned to the test group, immediate digital impression after implant surgery with crown delivery 4 months later. The remaining 20 patients were assigned to the control group, staged digital impressions 4 months after implant surgery, and crown delivery 1 month later. Both workflows involved free‐model CAD‐CAM crown fabrications. The crowns were scanned before and after clinical adjustment using an intraoral scanner (TRIOS Color; 3Shape). Two 3D digital models were trimmed and superimposed to evaluate the dimensional changes using Geomagic Control software. Chairside times for the entire workflow were recorded. Kruskal–Wallis was performed to compare crown adjustments between two groups, while One‐way ANOVA was used to compare chairside time durations between the test and control groups. Results: All crowns were delivered without refabrication. The average maximum occlusion adjustment of crowns was −353.2 ± 207.1 μm in the test group and −212.7 ± 150.5 μm in the control group (p = 0.02). The average area of occlusal adjustment, measured as an area of deviation larger than 100 μm, was 14.8 ± 15.3 and 8.4 ± 8.1 mm2 in the test and control groups, respectively (p = 0.056). There were no significant differences in the mesial and distal contact adjustment amounts, or the maximum deviations of the proximal area, between the two groups. The mean chair‐side time was 50.25 ± 13.48 and 51.20 ± 5.34 min in the test and control groups, respectively (p = 0.763). Conclusions: The immediate impression method in the digital workflow for single‐unit implants required more occlusal adjustments of crowns but showed similar chairside times compared to the staged impression method. [ABSTRACT FROM AUTHOR]

Aim: To explore the features of and potential landmarks that predict crestal ridge remodeling after immediate implant placement and provisionalization (IIPP) with thin buccal plate phenotype in the anterior maxilla. Materials and methods: Patients requiring IIPP of single maxillary incisor with thin buccal bone plate (<1 mm) were recruited. Cone‐beam computed tomography (CBCT), performed before and 6 months after the intervention, were three‐dimensionally superimposed. A virtual line connecting the bony emergence points of adjacent teeth was drawn as a reference. The facial–coronal alveolar crest of the extraction socket and healed ridge were located in mesial, middle and distal cross‐sectional planes, and linear ridge reductions were measured. The correlation between ridge reduction and local factors was analyzed. Results: Fifty patients were included. From the extraction socket to healed ridge, the alveolar crest underwent linear bone reduction of 1.50 ± 0.50, 1.54 ± 0.66 and 1.65 ± 0.73 mm in the mesial, middle, and distal regions in an apical–palatal direction. The middle region had significantly higher horizontal (facial–palatal) but lower vertical (coronal–apical) bone reduction than the mesial and distal areas (P < 0.01). The facial–coronal ridge crest of the healed ridge located close to the reference line. Ridge reduction positively correlated with the distance between the initial facial–coronal crest of the extraction socket and the reference line (P < 0.01). Conclusions: Alveolar crest of the socket lost its curvature and tended to attain a flat profile after IIPP due to inconsistent ridge reduction in middle, mesial and distal areas. The reference line may be a potential landmark for predicting the ridge crest after remodeling. [ABSTRACT FROM AUTHOR]

In order to understand the mechanism of dust aerosol influence on regional climate change, it is crucial to quantify the radiative forcing effect of dust aerosols. However, studies on the direct radiative forcing of dust aerosols over long time series in China are still lacking. The direct radiative forcing effect of dust aerosols in China over the past 20 years was simulated and evaluated based on the WRF-Chem (Weather Research and Forecasting model coupled to Chemistry) model in conjunction with remote sensing satellites and ground-based observations. The results showed that dust aerosols exhibited an obvious inter-annual positive radiative forcing effect (about 0.38 W m−2) on net radiation at the top of the atmosphere, mainly in northwest China and the North China Plain, while at the atmosphere dust aerosols presented negative radiative forcing effects on shortwave radiation and positive effects on longwave radiation, with a value of 1.54 W m−2 of net radiative forcing, showing a warming effect. Dust aerosols have a net radiative forcing value of −1.16 W m−2 at the surface, indicating a cooling effect, with a positive forcing effect on longwave radiation and a negative forcing effect on shortwave radiation, both of which coincide with the geographical distribution of dust aerosol concentrations. In terms of inter-monthly variations, at both the atmosphere and top of the atmosphere, the dust aerosols net radiative forcing values showed an increasing trend, with March (−0.20 W m−2 and 0.68 W m−2) < April (0.48 W m−2 and 1.44 W m−2) < May (0.94 W m−2 and 2.42 W m−2). Meanwhile, at the surface, the dust aerosols net radiative forcing values displayed a decreasing trend, with March (−0.88 W m−2) > April (−0.96 W m−2) > May (−1.48 W m−2). [ABSTRACT FROM AUTHOR]

Vegetable soybean (Glycine max), known as edamame, has a high nutritional and market value. It is a relatively new crop in North America and Africa. The amino acid profile is important for the nutritional quality of edamame, and a challenge facing its genetic improvement is evaluating its amino acids rapidly. To explore a drying method suitable for the fast evaluation of edamame nutritional profiles, fresh seed samples of 20 soybean genotypes were dried using freeze, low- and high-heat drying methods, and their amino acid contents were analyzed by near-infrared reflectance (NIR) technology. Three-year results indicated that there were significant differences between the years of samplings and among genotypes for all amino acids. Significant differences existed between the drying methods for most amino acids except for leucine and the total amino acid. Low-heat drying at 65 °C and freeze drying showed similar results and were highly comparable to each other for ANOVA and repeatability estimation. The estimates of repeatability under the individual drying methods were 73–94%, except for tryptophan, cysteine and methionine; meanwhile, higher estimates (85–99%) were computed using the combined data of all three drying methods, with few exceptions. Two sulfur-containing amino acids were showed to be more sensitive to high temperature than the others. Six genotypes exhibited higher contents of all the 18 major amino acids and are recommended to be used for the nutritional quality improvement of edamame and other food-grade specialty soybeans. In conclusion, the low-heat drying method can serve as an alternative to freeze drying, and can be used in the large-scale drying of fresh edamame and in the evaluation of seed amino acids in research. [ABSTRACT FROM AUTHOR]

SUMMARY: Cucumber (Cucumis sativus) originated in tropical areas and is very sensitive to low temperatures. Cold acclimation is a universal strategy that improves plant resistance to cold stress. In this study, we report that heat shock induces cold acclimation in cucumber seedlings, via a process involving the heat‐shock transcription factor HSFA1d. CsHSFA1d expression was improved by both heat shock and cold treatment. Moreover, CsHSFA1d transcripts accumulated more under cold treatment after a heat‐shock pre‐treatment than with either heat shock or cold treatment alone. After exposure to cold, cucumber lines overexpressing CsHSFA1d displayed stronger tolerance for cold stress than the wild type, whereas CsHSFA1d knockdown lines obtained by RNA interference were more sensitive to cold stress. Furthermore, both the overexpression of CsHSFA1d and heat‐shock pre‐treatment increased the endogenous jasmonic acid (JA) content in cucumber seedlings after cold treatment. Exogenous application of JA rescued the cold‐sensitive phenotype of CsHSFA1d knockdown lines, underscoring that JA biosynthesis is key for CsHSFA1d‐mediated cold tolerance. Higher JA content is likely to lead to the degradation of CsJAZ5, a repressor protein of the JA pathway. We also established that CsJAZ5 interacts with CsICE1. JA‐induced degradation of CsJAZ5 would be expected to release CsICE1, which would then activate the ICE–CBF–COR pathway. After cold treatment, the relative expression levels of ICE–CBF–COR signaling pathway genes, such as CsICE1, CsCBF1, CsCBF2 and CsCOR1, in CsHSFA1d overexpression lines were significantly higher than in the wild type and knockdown lines. Taken together, our results help to reveal the mechanism underlying heat shock‐induced cold acclimation in cucumber. Significance Statement: Cold acclimation is a universal strategy that improves plant resistance to cold stress. In this study, we discovered that a heat‐shock pre‐treatment improves the tolerance of cucumber seedlings for low‐temperature stress, and that CsHSFA1d and JA play important roles in this cold acclimation process. Our results will help to reveal the mechanism underlying heat shock‐induced cold acclimation in cucumber. [ABSTRACT FROM AUTHOR]

Purpose: This is a clinical study to compare complete digital workflows generated using intraoral scanning and the split‐file technique with a conventional workflow for cement‐retained implant‐supported restorations. Materials and methods: Forty patients requiring posterior single‐unit implant restorations were included. Twenty patients were randomly assigned to the complete digital workflow group, involving intraoral scanning and manufacture of cement‐retained crowns using the split‐file technique (test group). The remaining 20 patients were assigned to the hybrid workflow group (control group), involving conventional impressions and CAD‐CAM fabricated crowns based on stone casts. Scanning of the crowns was performed before and after clinical adjustment using an intraoral scanner (TRIOS Color; 3Shape). Two 3D digital models were trimmed and superimposed to evaluate changes in dimensions using Geomagic Control 2014 software. Chair‐side and laboratory times for the entire workflow were recorded. Independent‐sample t tests were used for the statistical analysis. Results: All crowns were inserted without refabrication. The average maximum occlusal adjustment of the crowns, measured as maximum deviation of occlusal area in superimposed pre and post scans, was −212.7 ± 150.5 and −330.7 ± 192.5 µm in the test and control groups, respectively (p = 0.037). The average area of occlusal adjustment, measured as area of deviation larger than 100 µm, was 8.4 ± 8.1 and 17.1 ± 12.3 mm2 in the test and control groups, respectively (p = 0.012). The mesial and distal contact adjustment amounts, maximum deviations of proximal area, were −33.0 ± 96.2 and −48.6 ± 70.5 µm in the test group, and −3.7 ± 66.7 µm and −11.4 ± 106.7 µm in the control group, respectively. The mean chair‐side time was 20.20 ± 3.00 and 26.65 ± 4.53 minutes in the test and control groups, respectively (p < 0.001). The mean laboratory time was 43.70 ± 5.56 and 84.55 ± 5.81 minutes in the test and control groups, respectively (p < 0.001). Conclusions: Single‐unit cement‐retained crowns with complete digital workflows required fewer crown adjustments and had shorter clinical and laboratory times compared to conventional impressions and hybrid workflows. Digital impressions and the split‐file technique provided customized abutments and cement‐retained crowns, thus broadening the indications for digital workflows for implants. [ABSTRACT FROM AUTHOR]

Jasmonic acid (JA) is a key regulator of plant defense responses. Although the transcription factor MYC2, the master regulator of the JA signaling pathway, orchestrates a hierarchical transcriptional cascade that regulates the JA responses, only a few transcriptional regulators involved in this cascade have been described. Here, we identified the basic helix‐loop‐helix (bHLH) transcription factor gene in tomato (Solanum lycopersicum), METHYL JASMONATE (MeJA)‐INDUCED GENE (SlJIG), the expression of which was strongly induced by MeJA treatment. Genetic and molecular biology experiments revealed that SlJIG is a direct target of MYC2. SlJIG knockout plants generated by gene editing had lower terpene contents than the wild type from the lower expression of TERPENE SYNTHASE (TPS) genes, rendering them more appealing to cotton bollworm (Helicoverpa armigera). Moreover, SlJIG knockouts exhibited weaker JA‐mediated induction of TPSs, suggesting that SlJIG may participate in JA‐induced terpene biosynthesis. Knocking out SlJIG also resulted in attenuated expression of JA‐responsive defense genes, which may contribute to the observed lower resistance to cotton bollworm and to the fungus Botrytis cinerea. We conclude that SlJIG is a direct target of MYC2, forms a MYC2‐SlJIG module, and functions in terpene biosynthesis and resistance against cotton bollworm and B. cinerea. [ABSTRACT FROM AUTHOR]

The cover image is based on the Original Article The facial–coronal ridge crest alterations after single immediate implant placement and provisionalization with thin buccal plate phenotype in anterior maxilla: A radiographic case‐series study by Chun Yi DMD et al., https://doi.org/10.1111/cid.13280. [ABSTRACT FROM AUTHOR]

Improving plant water‐use efficiency (WUE) is important to plant survival and crop yield in the context of water limitation. In this study, SlTLFP8 (Tubby‐like F‐box protein 8) was identified as an osmotic‐induced gene in tomato. Transgenic tomato with up‐regulated expression of SlTLFP8 showed enhanced water‐deficient resistance, whereas knockout mutants generated by CRISPR/Cas9 were more sensitive to water deficit. SlTLFP8 overexpression significantly enhanced WUE by suppressing transpiration under both water‐sufficient and water‐deficient conditions. Further study showed that overexpressing SlTLFP8 significantly increased leaf epidermal cell size and thereby decreased stomatal density 10–20%, conversely SlTLFP8 knockout resulted in decreased cell size and thereby increased stomatal density 20–50%. SlTLFP8 overexpression and knockout modulated ploidy levels in leaf cells. Changes in expression of cell cycle related genes also indicated that SlTLFP8 affected cell size and stomatal density through endocycle transition. Despite changes in stomata density and transpiration, altering the expression of SlTLFP8 did not change photosynthesis. Additionally, biomass was not altered and there was little difference in fruit yield for transgenic and wild type lines under water‐sufficient and water‐deficient conditions. Our results demonstrate the effect of SlTLFP8 on endoreduplication and the potential of SlTLFP8 for improvement of WUE. Brief Summery: This work found a new mechanism of TLP (Tubby like protein) response to water‐deficient stress. SlTLFP8, a member of TLP family, regulates water‐deficient resistance by modulating water loss via affecting stomatal density. Expression of SlTLFP8 was induced by osmotic stress. Transgenic tomato lines with SlTLFP8 overexpression or SlTLFP8 knockout showed significantly differences in water‐use efficiency (WUE) and water‐deficient resistance. The difference of leaf water loss caused by transpiration is the main explanation of the difference in WUE and water‐deficient resistance. Additionally, overexpressing SlTLFP8 significantly decreased stomatal density, while SlTLFP8 knockout resulted in increased stomatal density, and SlTLFP8 affected stomatal density through endoreduplication and altered epidermal cell size. Despite changes in stomata density, altering the expression of SlTLFP8 did not result in distinct changes in photosynthesis, biomass and yield of tomato. This work found a new mechanism of TLP (Tubby like protein) response to water‐deficient stress. SlTLFP8, a member of TLP family, regulates water‐deficient resistance by modulating water loss via affecting stomatal density. Expression of SlTLFP8 was induced by osmotic stress. Transgenic tomato lines with SlTLFP8 overexpression or SlTLFP8 knockout showed significantly differences in water‐use efficiency (WUE) and water‐deficient resistance. The difference of leaf water loss caused by transpiration is the main explanation of the difference in WUE and water‐deficient resistance. Additionally, overexpressing SlTLFP8 significantly decreased stomatal density, while SlTLFP8 knockout resulted in increased stomatal density, and SlTLFP8 affected stomatal density through endoreduplication and altered epidermal cell size. Despite changes in stomata density, altering the expression of SlTLFP8 did not result in distinct changes in photosynthesis, biomass and yield of tomato. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the hard and soft tissue alterations of immediately placed and provisionalized implants with or without connective tissue graft (CTG). Materials and Methods: Single unsalvageable maxillary incisors were replaced with immediately placed and provisionalized implants in 42 participants. The patients were randomly assigned to receive simultaneous CTG (test group) and not receive CTG (control group). Digital impression and cone‐beam computed tomography images were obtained before extraction and after 6 months. Mid‐facial gingival margin migrations, soft tissue contour changes and hard tissue remodelling were analysed and compared between the two groups using three‐dimensional superimposition method. Results: Forty participants completed the study. The test group showed significantly less buccal tissue collapse in the area 2–5 mm apical to the gingival margin. In both groups, the mid‐facial gingival margin migrated in an apico‐palatal direction and the socket void, except for a triangular space in the bucco‐coronal region, demonstrated radiographic new bone formation without statistically significant differences. Conclusions: The CTG used with immediate implant placement and provisionalization could compensate for the facial tissue collapse, but it did not benefit maintenance of the mid‐facial gingival margin position during the 6‐month follow‐up. New bone formation observed radiographically can be expected in most areas of the socket void, regardless of CTG use (ChiCTR‐1900028494). [ABSTRACT FROM AUTHOR]

BACKGROUND Edamame, a vegetable soybean (Glycine max) grown mainly in Asia, has high nutritional and market value and is a relatively new crop to North America. By 2 years of field trials, we evaluated the seed composition traits in 54 genotypes to analyze the differences and relationship between edamame seeds dried by two oven‐drying methods and mature soybeans. RESULTS: The genotypic differences were significant for all the traits investigated. Significant differences also existed between the two sets of dried edamame and mature seeds. Protein content in mature soybean averaged 426.8 g kg−1, and 432.8 g kg−1 and 405.6 g kg−1 for shelled‐dried and unshelled‐dried edamame respectively. Oil content in shelled‐dried and unshelled‐dried edamame averaged 206.3 g kg−1 and 212.6 g kg−1 respectively, and 195.8 g kg−1 for mature soybean. Sucrose content in mature soybean (60.2 g kg−1) was approximately 1.5 and 3 times that of unshelled‐dried and shelled‐dried edamame respectively. Mature soybean also exhibited the highest concentrations of stachyose and total sugars, followed by unshelled‐dried and shelled‐dried edamame. The broad‐sense heritability estimates of traits in mature soybean (49.41–89.16%) were higher than those of edamame (10.26–78.96%). Higher broad‐sense heritability was uncovered for protein and oil, but lower estimates for sugars, fiber, and ash. Positive correlations were detected between the two sets of edamame seeds and mature soybean for protein and oil (r = 0.63–0.88). CONCLUSION: The results suggest that indirect selection through mature seeds is helpful for the improvement of protein and oil in edamame, whereas the improvement of seed sugars in edamame is more challenging. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Melatonin (N-acetyl-5-methoxytryptamine) plays important roles in plant developmental growth, especially in root architecture. The similarity in both chemical structure and biosynthetic pathway suggests a potential linkage between melatonin and auxin signaling. However the molecular mechanism regulating this melatonin-mediated root architecture changes is not yet elucidated. In the present study, we re-analyzed previously conducted transcriptome data and identified 16 auxin-related genes whose expression patterns were altered by treatment with melatonin. Several of these genes encoding important auxin transporters or strongly affecting auxin transport were significantly down regulated. In wild type Arabidopsis, Melatonin inhibited both primary root growth and hypocotyl elongation, but enhanced lateral root development in a dose dependent manner. However, the lateral-root-promoting role of melatonin was abolished when each individual null mutant affecting auxin transport including pin5, wag1, tt4 and tt5, was examined. Furthermore, melatonin acts synergistically with auxin to promote lateral root development in wild type Arabidopsis, but such synergistic effects were absent in knockout mutants of individual auxin transport related genes examined. These results strongly suggest that melatonin enhances lateral root development through regulation of auxin distribution via modulation of auxin transport. A working model is proposed to explain how melatonin and auxin act together to promote lateral root development. The present study deepens our understanding of the relationship between melatonin and auxin signaling in plant species. [ABSTRACT FROM AUTHOR]

Melatonin plays an important role in stress tolerance in plants. In this study, exogenous melatonin significantly alleviated the dwarf phenotype and inhibited the decrease of plant fresh weight induced by excess copper (Cu2+). Our results indicated that melatonin alleviated Cu2+ toxicity by improving Cu2+ sequestration, carbon metabolism and ROS (reactive oxygen species) scavenging, rather than by influencing the Cu2+ uptake under excess Cu2+ conditions. Transcriptome analysis showed that melatonin broadly altered gene expression under Cu2+ stress. Melatonin increased the levels of glutathione and phytochelatin to chelate excess Cu2+ and promoted cell wall trapping, thus keeping more Cu2+ in the cell wall and vacuole. Melatonin inhibited ROS production and enhanced antioxidant systems at the transcriptional level and enzyme activities, thus building a line of defense in response to excess Cu2+. The distribution of nutrient elements was recovered by melatonin which was disturbed by Cu2+. In addition, melatonin activated carbon metabolism, especially glycolysis and the pentose phosphate pathway, to generate more ATP, an intermediate for biosynthesis. Taken together, melatonin alleviated Cu2+ toxicity in cucumber via multiple mechanisms. These results will help to resolve the toxic effects of Cu2+ stress on plant growth and development. These results can be used for new strategies to solve problems associated with Cu2+ stress. [ABSTRACT FROM AUTHOR]

The NAC transcription factors play vital roles in responding to drought stress in plants; however, the molecular mechanisms remain largely unknown in cucumber. Suppression of CsATAF1 via RNA interference (RNAi) weakened drought stress tolerance in cucumber due to a higher water loss rate in leaves, a higher level of hydrogen peroxide (H2O2) and superoxide radicals (O2 ⋅-), increased malondialdehyde (MDA) content, lower Fv/Fm ratios and lower antioxidant enzyme activity. The analysis of root length and stomatal apertures showed that CsATAF1-RNAi cucumber plants were less responsive to ABA. In contrast, CsATAF1-overexpression (OE) plants showed increased drought stress tolerance and sensitivity to ABA. Quantitative PCR (qPCR) analysis showed that expression of several stress-responsive genes was significantly up-regulated in CsATAF1-OE transformants and down-regulated in CsATAF1-RNAi transformants. CsABI5, CsCu-ZnSOD and CsDREB2C were verified as direct target genes of CsATAF1. Yeast one-hybrid analysis and electrophoretic mobility shift assay (EMSA) further substantiated that CsATAF1 bound to the promoters of CsABI5, CsCu-ZnSOD and CsDREB2C. Transient expression in tobacco leaves and cucumber protoplasts showed that CsATAF1 directly up-regulated the expression of CsABI5, CsCu-ZnSOD and CsDREB2C. Our results demonstrated that CsATAF1 functioned as a positive regulator in response to drought stress by an ABA-dependent pathway and decreasing reactive oxygen species (ROS) accumulation in cucumber. [ABSTRACT FROM AUTHOR]

Although previous studies have found that melatonin can promote seed germination, the mechanisms involved in perceiving and signaling melatonin remain poorly understood. In this study, it was found that melatonin was synthesized during cucumber seed germination with a peak in melatonin levels occurring 14 hr into germination. This is indicative of a correlation between melatonin synthesis and seed germination. Meanwhile, seeds pretreated with exogenous melatonin (1 μM) showed enhanced germination rates under 150 mM NaCl stress compared to water-pretreated seeds under salinity stress. There are two apparent mechanisms by which melatonin alleviated salinity-induced inhibition of seed germination. Exogenous melatonin decreased oxidative damage induced by NaCl stress by enhancing gene expression of antioxidants. Under NaCl stress, compared to untreated control, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly increased by approximately 1.3-5.0-fold, with a concomitant 1.4-2.0-fold increase of CsCu-ZnSOD, CsFe-ZnSOD, CsCAT, and CsPOD in melatoninpretreated seeds. Melatonin also alleviated salinity stress by affecting abscisic acid (ABA) and gibberellin acid (GA) biosynthesis and catabolism during seed germination. Compared to NaCl treatment, melatonin significantly upregulated ABA catabolism genes (e.g., CsCYP707A1 and CsCYP707A2, 3.5 and 105-fold higher than NaCl treatment at 16 hr, respectively) and downregulated ABA biosynthesis genes (e.g., CsNECD2, 0.29-fold of CK2 at 16 hr), resulting in a rapid decrease of ABA content during the early stage of germination. At the same time, melatonin positively up-regulated GA biosynthesis genes (e.g., GA20ox and GA3ox, 2.3 and 3.9-fold higher than NaCl treatment at 0 and 12 hr, respectively), contributing to a significant increase of GA (especially GA4) content. In this study, we provide new evidence suggesting that melatonin alleviates the inhibitory effects of NaCl stress on germination mainly by regulating the biosynthesis and catabolism of ABA and GA4. [ABSTRACT FROM AUTHOR]

Melatonin is a ubiquitous molecule and exists across kingdoms including plant species. Studies on melatonin in plants have mainly focused on its physiological influence on growth and development, and on its biosynthesis. Much less attention has been drawn to its affect on genome-wide gene expression. To comprehensively investigate the role(s) of melatonin at the genomics level, we utilized mRNA-seq technology to analyze Arabidopsis plants subjected to a 16-hour 100 pM (low) and 1 mM (high) melatonin treatment. The expression profiles were analyzed to identify differentially expressed genes. 100 pM melatonin treatment significantly affected the expression of only 81 genes with 51 down-regulated and 30 up-regulated. However, 1 mM melatonin significantly altered 1308 genes with 566 up-regulated and 742 down-regulated. Not all genes altered by low melatonin were affected by high melatonin, indicating different roles of melatonin in regulation of plant growth and development under low and high concentrations. Furthermore, a large number of genes altered by melatonin were involved in plant stress defense. Transcript levels for many stress receptors, kinases, and stress-associated calcium signals were up-regulated. The majority of transcription factors identified were also involved in plant stress defense. Additionally, most identified genes in ABA, ET, SA and JA pathways were up-regulated, while genes pertaining to auxin responses and signaling, peroxidases, and those associated with cell wall synthesis and modifications were mostly down-regulated. Our results indicate critical roles of melatonin in plant defense against various environmental stresses, and provide a framework for functional analysis of genes in melatonin-mediated signaling pathways. [ABSTRACT FROM AUTHOR]

A comprehensive investigation was carried out to determine the changes that occurred in water-stressed cucumber (Cucumis sativus L.) in response to melatonin treatment. We examined the potential roles of melatonin during seed germination and root generation and measured its effect on reactive oxygen species (ROS) levels, antioxidant enzyme activities, and photosynthesis. Melatonin alleviated polyethylene glycol induced inhibition of seed germination, with 100 μm melatonin-treated seeds showing the greatest germination rate. Melatonin stimulated root generation and vitality and increased the root:shoot ratio; therefore, melatonin may have an effect on strengthening cucumber roots. Melatonin treatment significantly reduced chlorophyll degradation. Seedlings treated with 100 μm melatonin clearly showed a higher photosynthetic rate, thus reversing the effect of water stress. Furthermore, the ultrastructure of chloroplasts in water-stressed cucumber leaves was maintained after melatonin treatment. The antioxidant levels and activities of the ROS scavenging enzymes, i.e., superoxide dismutase, peroxidase, and catalase, were also increased by melatonin. These results suggest that the adverse effects of water stress can be minimized by the application of melatonin. [ABSTRACT FROM AUTHOR]

Presents a study of the genetic effect of cytoplasm on resistance to Gibberella zeae organism in alloplasmic wheat. Resistance of explant calli; Identification of inoculating single fixed position; Identification of field resistance.

Cellulose is the major component of cell wall materials. A 300 bp specific fragment from the cDNA fragment was chosen to insert into vector pFGC1008 at forward and reverse orientations to construct the recombinant RNAi vector. Knockdown of BoiCesA caused 'dwarf' phenotype with smaller leaves and a loss of the content of cellulose. Moreover, RT-PCR analysis confirmed that the expression of the RNAi apparatus could repress expression of the CesA gene. Meanwhile, examination of the leaves from the T3 of RNAi transformants indicated reduction of cell expansion in vascular bundles, particularly on their abaxial surface. The proline and soluble sugar content increased contrarily. Under the salt stress, the T3 of RNAi plants showed significant higher resistance. The expression levels of some salt tolerance related genes (BoiProH, BoiPIP2;2, BoiPIP2;3) were significantly changed in T3 of RNAi plants. The results showed that the hairpin structure of CesA specific fragment inhibited the endogenous gene expression and it was proved that the cDNA fragment was relevant to the cellulose biosynthesis. Moreover, modulation cellulose synthesis probably was an important influencing factor in polysaccharide metabolism and adaptations of plants to stresses. This will provide technological possibilities for the further study of modulation of the cellulose content of crops. [ABSTRACT FROM AUTHOR]

• SoHSC70 cDNA was isolated from spinach (Spinacia oleracea L.), and its protein was located in the nucleus and cytoplasm. • Overexpressing SoHSC70 in spinach calli and Arabidopsis enhanced their thermotolerance. • SoHSC70 overexpression altered MDA content, ROS accumulation, and activities of antioxidant enzymes after heat treatment. • Overexpressing SoHSC70 improves heat tolerance by reducing ROS accumulation, improving activities of antioxidant enzymes. High temperature is a major environmental factor affecting plant growth. Heat shock proteins (Hsps) are molecular chaperones that play important roles in improving plant thermotolerance during heat stress. Spinach (Spinacia oleracea) is very sensitive to high temperature; however, the specific function of Hsps in spinach is unclear. In this study, cytosolic heat shock 70 protein (SoHSC70), which was induced by heat stress, was cloned from spinach. Overexpressing SoHSC70 in spinach calli and Arabidopsis enhanced their thermotolerance. In contrast, spinach seedlings with silenced SoHSC70 by virus-induced gene silencing (VIGS) showed more sensitivity to heat stress. Further analysis revealed that overexpressing SoHSC70 altered relative electrical conductivity (REC), malondialdehyde (MDA) content, photosynthetic rate, reactive oxygen species (ROS) accumulation and the activities of antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) after the heat treatment. Taken together, our results suggest that overexpressing SoHSC70 positively affects heat tolerance by reducing membrane damage and ROS accumulation and improving activities of antioxidant enzymes. [ABSTRACT FROM AUTHOR]

Highlights • PvNAC1 cDNA was isolated from switchgrass (Panicum virgatum L.) and its protein was located in the nucleus with the C-terminal region containing a transcriptional activation domain. • Overexpression of PvNAC1 increased biomass yield and cellulose content whereas suppressing expression of PvNAC1 by RNAi reduced the biomass dry weight. • Overexpression of PvNAC1 showed more tolerance to salt stress by reducing Na + content in shoot and root, and enhancing ROS scavenging enzyme activities, while RNAi plants were more sensitive to salt stress. • These results show that PvNAC1 functions as a transcriptional activator in response to salt stress and growth. Abstract Switchgrass (Panicum virgatum L.) is a bioenergy crop; thus, it is important to improve biomass to effectively produce bioethanol, particularly under adverse stress conditions. NAC transcription factors are involved in the abiotic stress response. PvNAC1 was isolated in the nucleus of switchgrass, with its C-terminal region containing a transcriptional activation domain. PvNAC1 expression was induced by dehydration, salt, H 2 O 2 , and abscisic acid treatments. Overexpressing (OE) PvNAC1 improved growth performance, leading to significantly taller and heavier (dry weight) plants. Moreover, cellulose content was significantly higher in OE plants, indicating that PvNAC1 plays an important role regulating growth and bioethanol production. PvNAC1 RNA interference (RNAi) switchgrass plants exhibited reduced dry weight and cellulose content. OE PvNAC1 enhanced tolerance to salt stress, through higher reactive oxygen species scavenging ability and less Na+ and more K+ accumulation in roots and shoots. RNAi plants were more sensitive to salt stress. The quantitative polymerase chain reaction results revealed that some stress responsive genes, three antioxidant enzymatic genes, and an ion homeostasis-related gene were upregulated in OE plants and downregulated in RNAi plants. These results show that PvNAC1 functions as a transcriptional activator in response to salt stress and growth. [ABSTRACT FROM AUTHOR]

Abstract Tungsten-copper (W-Cu) composites are used as high temperature frictional materials under special service conditions for electromagnetic gun rail and precision guide for rolled pieces due to their good ablation resistance and electrical conductivity. However, they have poor wear resistance at elevated temperatures. In this paper, surface carburization method was applied on the W-20 wt%Cu composite to investigate the mechanisms of carburization and its effects on the high temperature friction behavior of composite. Carburization process has been done at a temperature of 1100 °C for 30 h. The obtained results showed that carburizing at 1100 °C with a dwelling time of 30 h resulted into formation of a carburized layer and a dense intermediate sub-layer on the substrate. Also, the surface carburized layer with a thickness of about 70 μm composed of mixed phases of graphite, WC and W 2 C. The hardness of carburized layer (~HV454) was significantly higher than that of substrate (HV223). Also, bending strength of the carburized W-Cu composites has been significantly improved, although their electrical conductivity and tensile strength was decreased slightly. The carburization mechanism of the W-Cu composites was found to be dominant by carbon atom diffusion through reaction with W atoms and formation of surface liquid copper, which promoted migration and diffusion of tungsten and carbon at high temperatures. Average coefficients of friction and wear rate of carburized W-Cu composites are all lower than these of un-carburized W-Cu composites owing to the presence of surface carburized layer. Also, formation of CuWO 4 at high temperatures reduced the friction and wear resistance of the W-Cu composites. Highlights • First report on carburization of W-Cu composite for high temperature wear resistance • Carburization is dominant by C/W diffusion through reaction and surface liquid Cu. • The hardness of carburized layer (~HV454) was the double of substrate (HV223). • Formation of CuWO 4 is key reason to reduce wear at high temperatures. [ABSTRACT FROM AUTHOR]

Seed germination is important for early plant morphogenesis as well as abiotic stress tolerance, and is mainly controlled by the phytohormones abscisic acid (ABA) and gibberellic acid (GA). Our previous studies identified a salt-tolerant tomato cultivar, LA2711, which is also a fast-germinating genotype, compared to its salt-sensitive counterpart, ZS-5. In an effort to further clarify the mechanism underlying this phenomenon, we compared the dynamic levels of ABA and GA 4 , the transcript abundance of genes involved in their biosynthesis and catabolism as well as signal transduction between the two cultivars. In addition, we tested seed germination sensitivity to ABA and GAs. Our results revealed that insensitivity of seed germination to exogenous ABA and low ABA content in seeds are the physiological mechanisms conferring faster germination rates of LA2711 seeds. SlCYP707A2 , which encodes an ABA catabolic enzyme, may play a decisive role in the fast germination rate of LA2711, as it showed a significantly higher level of expression in LA2711 than ZS-5 at most time points tested during germination. The current results will enable us to gain insight into the mechanism(s) regarding seed germination of tomato and the role of fast germination in stress tolerance. [ABSTRACT FROM AUTHOR]

Abstract: The response and adaptation of plants to different environmental stresses are of great interest as they provide the key to understanding the mechanisms underlying stress tolerance. In this study, the changing patterns of four endogenous hormones and various physiological and biochemical parameters of both a salt-tolerant (LA2711) and a salt-sensitive (ZS-5) tomato cultivar were examined under salt stress and non-stress conditions. Additionally, the transcription of key genes in the abscisic acid (ABA) biosynthesis and metabolism were analyzed at different time points. The results indicated that gene expression responsible for ABA biosynthesis and metabolism coincided with the hormone level, and SlNCED1 and SlCYP707A3 may play major roles in the process. LA2711 performed superior to ZS-5 on various parameters, including seed germination, Na+ compartmentation, selective absorption of K+, and antioxidant enzymes activity. The difference in salt tolerance between the two genotypes could be attributed to the different levels of ABA due to differences in gene expression of key genes in ABA biosynthesis and metabolism. Although gibberellin, cytokinin and auxin were involved, our results indicated that ABA signaling plays a major role in tomato salt tolerance. As compared to ZS-5, LA2711 had a higher capability to selectively absorb and redistribute K+ and a higher tolerance to Na+ in young leaves, which may be the main physiological mechanisms of salt tolerance. [Copyright &y& Elsevier]

• Melatonin treatment triggered increased carotenoid accumulation. • Melatonin treatment did not enhance carotenoid levels in Nr tomato. • Ethylene acts in melatonin-induced biosynthesis of carotenoids. In tomato, red color is a key commercial trait and arises from the accumulation of carotenoids. Previous studies have revealed that melatonin promotes lycopene accumulation and ethylene production. However, it is unclear if melatonin similarly increases other carotenoids, and whether any increase of carotenoids in tomato fruit is directly related to ethylene production. In this study, changes in carotenoid profiles during fruit ripening were investigated in control (CK) and in fruits treated with melatonin (M50). The α, β-carotene, and lycopene levels were significantly increased in M50, and there was increased carotenoid biosynthetic gene expression. We also observed up-regulated transcript levels of SlRIN , SlCNR , and SlNOR in M50 compared to CK. To better understand the regulation of carotenoid biosynthesis by melatonin and its potential response to endogenous ethylene, we tested an ethylene-insensitive mutant, Never ripe (Nr). Melatonin-treated Nr failed to accumulate more carotenoids compared to CK, although there was significantly changed ethylene production. Additionally, there was no general upregulation of expression of ripening-related genes in this mutant under melatonin treatment. These results suggest melatonin function might require ethylene to promote carotenoid synthesis in tomato. [ABSTRACT FROM AUTHOR]