Resveratrol is a naturally occurring plant stilbene that exhibits a wide range of valuable biological and pharmacological properties. Although the beneficial effects of trans-resveratrol to human ...health and plant protection against fungal pathogens and abiotic stresses are well-established, yet little is known about the molecular mechanisms regulating stilbene biosynthesis in plant defense progress.
Here, we cloned and identified the Chinese wild grape (Vitis davidii) R2R3-MYB transcription factor VdMYB1, which activates defense responses against invading pathogen. VdMYB1 transcripts were significantly upregulated after inoculation with the grapevine powdery mildew fungus Erysiphe necator (Schw.) Burr. Transient expression analysis using onion epidermal cells and Arabidopsis thaliana protoplasts showed that VdMYB1 was localized in the nucleus. Yeast one-hybrid assays revealed that VdMYB1 acts as a transcriptional activator. Grapevine leaves transiently overexpressing VdMYB1 showed a lower number of fungal conidiophores compared with wild-type leaves. Overexpression of VdMYB1 in grapevine leaves did not alter the expression of genes in salicylic acid- and jasmonate-dependent pathways, but affected the expression of stilbene synthase (STS) genes, key regulators of flavonoid metabolism. Results of electrophoretic mobility shift assays and in vivo transcriptional activation assays showed that VdMYB1 binds to the MYB binding site (MYBBS) in the STS2 gene promoter, thus activating STS2 transcription. In heterologous expression assays using tobacco leaves, VdMYB1 activated STS2 gene expression and increased the accumulation of resveratrol.
Our study showed that VdMYB1 activates STS2 gene expression to positively regulate defense responses, and increases the content of resveratrol in leaves.
In grapevine, the MYB transcription factors play an important role in the flavonoid pathway. Here, a R2R3-MYB transcription factor,
, isolated from
cultivar Yatomi Rose, may be involved in ...anthocyanin biosynthesis as a transcriptional repressor. VvMYBC2L2 was shown to be a nuclear protein. The gene was shown to be strongly expressed in root, flower and seed tissue, but weakly expressed during the fruit development in grapevine. Overexpressing the
gene in tobacco resulted in a very marked decrease in petal anthocyanin concentration. Expression analysis of flavonoid biosynthesis structural genes revealed that chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), leucoanthocyanidin reductase (LAR) and UDP glucose flavonoid 3-
-glucosyl transferase (UFGT) were strongly down-regulated in the VvMYBC2L2-overexpressed tobacco. In addition, transcription of the regulatory genes AN1a and AN1b was completely suppressed in transgenic plants. These results suggested that VvMYBC2L2 plays a role as a negative regulator of anthocyanin biosynthesis.
This study was envisaged to investigate the physiological reasons affecting the embryo development and abortion of seedless grapes on the basis of the previous embryo rescue breeding techniques of ...seedless grapes. Specifically, the relationship between the embryo rescue breeding of seedless grapes and the change of polyamine content was evaluated, in order to provide hybrid germplasm in the breeding of new seedless grape cultivars. Four ovules of 4 naturally pollinated Eurasian seedless grape cultivars, including 'Thompson Seedless' grape (hereinafter referred to as 'Seedless White' grape), 'Flame Seedless' grape, 'Heshi Seedless' grape and 'Ruby Seedless' grape were employed for the study. Changes in the endogenous polyamine content, exogenous polyamine content, and the suitable combination of exogenous polyamines in the seedless grape berries and isolated ovules were determined during the best embryo rescue period. Furthermore, the effect of different exogenous polyamine contents on the germination and seedling rate of different seedless grape embryos was analyzed. In the best embryo rescue period, the number of ovules had different effects on the content of polyamines. For seedless grape cultivars with 4 ovules, a high content of polyamines was found to be more beneficial in the embryonic development. The existence of embryos had different effects on the development of embryos. In the ovules with embryo, an increase in the content of polyamine was beneficial to the growth and development of the ovule. Different ratios of exogenous polyamines had varying effects on the embryonic development. Putrescine (Put) exhibited the greatest effect on the embryonic development. Further, correlation analysis showed that different combinations of exogenous polyamines had varying effects on the embryonic development. A maximal ovule development was observed in the combination of exogenous polyamines of putrescine2+spermidine2+spermine1. For maximal embryo germination and seeding formation, the optimal combination was putrescine2+spermidine2+spermine2. Irrespective to the number of ovules or the existence of embryos, the results indicated that a high content of endogenous polyamines promoted the growth and development of embryos. The embryo rescue efficiency of different exogenous polyamines was different, and the appropriate combination of exogenous polyamines was beneficial to the growth and development of ovules, with a high development rate of the ovule and seedling.
The NAC (for NAM, ATAF1,2, and CUC2) proteins family are plant-specific transcription factors, which play important roles in leaf development and response to environmental stresses. In this study, an ...NAC gene,
, isolated from grapevine
L. "Yatomi Rose", was shown to be involved in leaf senescence. The quantity of
transcripts decreased with advancing leaf senescence in grapevine. Overexpressing the
gene in tobacco plants significantly delayed leaf senescence with respect to chlorophyll concentration, potential quantum efficiency of photosystem II (Fv/Fm), and ion leakage. Moreover, exogenous abscisic acid (ABA) markedly reduced the expression of
, and the ABA and salicylic acid (SA) concentration was lower in the
-overexpressing transgenic plants than in the wild-type plants. The
transgenic plants exhibited reduced sensitivity to ABA-induced senescence but no significant change in the sensitivity to jasmonic acid-, SA- or ethylene-induced senescence. Transcriptomic analysis and RNA expression studies also indicated that the transcript abundance of genes associated with ABA biosynthesis and regulation, including 9-
-epoxycarotenoid dioxygenase (
),
, zeaxanthin epoxidase1 (
), ABA DEFICIENT2 (
),
, and ABA INSENSITIVE 2 (
), was markedly reduced in the
-overexpressing plants. These results suggested that
plays a role as a negative regulator of leaf senescence by regulating ABA synthesis.
Across inherited complex fold‐and‐thrust belts (FTBs), shortening may be accommodated at different rates depending on structural style variations; such cases have rarely been documented We present ...the example of the Kepingtage FTB in southern Tianshan, which is bisected by the NNW‐trending left‐lateral strike‐slip Piqiang Fault (PQF) into eastern and western segments. The 1.45 ± 0.31–2.10 ± 0.42 mm/a shortening rate of the eastern segment is accommodated in a diffuse‐deformation pattern within the five‐row thrust‐anticlinal zone and the 2.36 ± 0.23–3.70 ± 0.59 mm/a shortening rate of the western segment is accommodated within the two‐row thrust‐anticlinal zone at the FTB front. To accommodate the latitudinal variability, the PQF exhibits a 2.30 ± 0.20–4.10 ± 0.40 mm/a segmentation strike‐slip rate. The 2.35 ± 0.33–4.20 ± 0.45 mm/a shortening rate of the Kepingtage FTB and southern Tianshan Fault is one‐third of the total convergence rate between the Tarim Basin and Kazakh Platform at 77°–79°E; hence, the complex Tianshan deformation occurred mainly at the FTB.
Plain Language Summary
The Kepingtage fold‐and‐thrust belt (FTB) in southern Tianshan is a typical imbricated thrust structure divided into eastern and western segments by a NNW‐trending left‐lateral strike‐slip fault (Piqiang Fault; PQF), which regulates inhomogeneous thrusting and shortening rates. The interaction between Kepingtage FTB shortening, PQF shear deformation, and rate accommodation within various thrust‐anticlinal zones remain unclear. Investigating fault kinematics and strain distribution is essential for describing regional deformation images and understanding deformation patterns. Herein, we utilized latest GPS data from 73 stations in Kepingtage FTB and adjacent areas to obtain the current crustal‐movement velocity field in the Kepingtage Block within the Eurasia reference framework. Deformation of the western segment occurs in front of Kepingtage FTB, and the shortening rate is accommodated in these structures. However, deformation and shortening rates of the east segment are diffused in the five‐row thrust‐anticlinal zone. The longitudinal variability can be attributed to inherited structures, wherein shortening is accommodated at different rates based on structure patterns. Our results confirm the deformation rate of active structures and effects of different faults on regional tectonic deformation. Moreover, deformation of the tectonically active foreland of Tianshan can be used as an analog for understanding the tectonic deformation of tectonically active mountain belts.
Key Points
GPS data from 73 stations in the Kepingtage fold‐and‐thrust belt (FTB) and adjacent areas reveal the current Kepingtage Block crustal‐movement velocity field
Shortening rate of Kepingtage FTB and adjacent areas is ∼1/3 of the total convergence rate between the Tarim Basin and Kazakh Platform
Shortening rates and deformation patterns vary due to the inherited evolution of the Kepingtage imbricate and pre‐existing structures
The mechanical properties of high-entropy alloys (HEAs) containing rare earth are improved by adding boron element. Under the condition that the content of rare-earth is fixed, FeCoNi1.5CuY0.2Bx ...high-entropy alloy with different boron atom ratios (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) is prepared by advanced microwave sintering process. The effect of boron addition with different atomic ratios on the phase evolution, microstructure, compressive mechanical properties and magnetic properties of the FeCoNi1.5CuY0.2 high-entropy alloy is emphatically studied. The results show that the phase transformation temperature decreases with the increase of boron content, which is conducive to the rapid sintering at low temperature. When boron content is less than 0.4 atomic ratio, the alloy is dominated by FCC base phase and BYO3, eliminating the oxidation phase of Y2O3. When boron adding amount as x = 0.4, it has the largest maximum compression ratio. When the amount of boron exceeds 0.4 atomic ratio, boride precipitates in the alloy, which increases the strength and hardness and at the cost of plasticity and soft magnetism. When the amount of boron is x = 1, the hardness arrives at utmost, and the compressive strength, yield strength and hardness are 1546 MPa, 1112 MPa and 367.1HV, respectively, which are 150%, 129% and 29.03% higher than those of boron-free sample. The improvement of mechanical properties is due to the fact that boron with small atomic size is easy to solute into the FCC base phase, forming interstitial solid solution, which results in lattice distortion and solid solution strengthening effect. And BY12 particles precipitated in BYO3 have dispersion strengthening effect on the alloy.
•Adding element yttrium and boron to the high-entropy-alloy will increase the difference in atomic size of the alloy system and increase the difficulty of atomic movement.•This characteristic can promote the formation of HCP structure.•The oxidation phase can be eliminated, therefore enhance the mechanical properties of the alloy.
Due to the nature of their work, nurses are more prone to experiencing psychological consequences than other healthcare workers. However, evidence on the emotional burden of nurse managers in China ...is limited. Furthermore, perceived organizational support has been approved that can affect mental health outcomes. Therefore, this study aimed to investigate the status quo and influencing factors of nurse managers' work stress, and their possible relationship with perceived organizational support, which could further provide more countermeasures to safeguard their health.
A cross-sectional online survey of 21 secondary and tertiary hospitals was conducted in a city in Sichuan province, Southwest China, using a convenience sampling method between October and November 2022. Data were collected using the general information questionnaire, the Chinese version of the Stress Overload Scale (SOS) and the perceived Organizational Support Scale (POSS). SPSS 23.0 was applied to analyze the data.
In total, 380 participants completed the survey. The median scores (interquartile range IQR) for SOS and POSS were 60.50 (50.00, 70.75) and 51.00 (44.00, 55.00), respectively. The work stress of the nurse managers was negatively correlated with perceived organizational support (P < 0.01). Multiple linear regression analysis showed that age older than 40 years, from secondary hospitals, working in emergency or pediatric wards, and professional qualification of supervisor nurse or deputy supervisor nurse, and the scores of POSS less than 51 significantly influenced the work stress of the nurse managers.
Our study shows that nurse managers are more prone to work stress, and organizational support can effectively reduce this stress. Governments and hospital administrators should pay more attention to providing comprehensive strategies based on various risk factors to protect and promote psychological health.
•The effect of microwave sintering temperature on microstructure and mechanical behavior of HEAp/Al composites is investigated.•Ferromagnetic FeCoNi1.5CrCu particles improve the microwave absorption ...capacity of composites and reinforce the composites under microwave conditions.•The evolution mechanism of interface bonding in the preparation of ferromagnetic HEAp/Al composites under the condition of microwave assisted sintering is elucidated.
The preparation of metal particle reinforced aluminum matrix composites by powder metallurgy has been widely studied in recent years. In this work, the effect of microwave sintering temperature on the microstructure and mechanical behavior of high-entropy alloys (HEAs) reinforced aluminum matrix composites prepared by powder metallurgy was investigated. Due to the outstanding microwave absorbing property of ferromagnetic HEAs particles, the composites sintering proceeded efficiently. At 480 °C, the aluminum matrix in the composite material is more compact, and the HEAs particles in the composite material are more evenly distributed, and the interface between HEAs particles and aluminum matrix is smooth. At 500 °C, the intensity of HEAs diffraction peak in the composite material changes significantly. At 520 °C, AlNi solid solution phase with BCC structure appears in the HEAs region, and the HEAs structure changes from FCC to FCC + BCC, and Al5Cr8, Al5Co2 and Al2Cu phases precipitate. At 480 °C, the nanohardness and elastic modulus at the interface reaches 1245.31 MPa and 72.45 GPa, respectively, showing relatively excellent interfacial bonding strength. The elastic modulus of both HEAs reinforcement and aluminum matrix decrease at a sintering temperature above 480 °C, and the composites have hard and brittle characteristics. At 480 °C, the macroscopic compression and yield strengths of composites are ~ 421.2 MPa and ~ 289.5 MPa, and the maximum shrinkage rate is ~65.3%, exhibiting excellent strength and toughness.
In grapevines, the MYB transcription factors play an important regulatory role in the phenylpropanoid pathway including proanthocyanidin, anthocyanin, and flavonoid biosynthesis. However, the role of ...MYB in abiotic stresses is not clear. In this study, an R2R3-MYB transcription factor,
VyMYB24
, was isolated from a high drought-tolerant Chinese wild
Vitis
species
V. yanshanesis
. Our findings demonstrated that it was involved in plant development and drought tolerance.
VyMYB24
is a nuclear protein and is significantly induced by drought stress. When over-expressed in tobacco,
VyMYB24
caused plant dwarfing including plant height, leaf area, flower size, and seed weight. The GA1+3 content in transgenic plants was reduced significantly, and spraying exogenous gibberellin could recover the dwarf phenotype of
VyMYB24
transgenic plants, suggesting that
VyMYB24
might inhibit plant development by the regulation of gibberellin (GA) metabolism. Under drought stress, the
VyMYB24
transgenic plants improved their tolerance to drought with a lower wilting rate, lower relative electrical conductivity, and stronger roots. Compared to wild-type tobacco plants,
VyMYB24
transgenic plants accumulated less reactive oxygen, accompanied by increased antioxidant enzyme activity and upregulated gene expression levels of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) genes. In addition, transgenic plants accumulated more proline, and their related synthetic genes
NtP5CR
and
NtP5CS
genes were significantly upregulated when exposed to drought. Besides, abiotic stress-responsive genes,
NtDREB, NtERD10C, NtERD10D
, and
NtLEA5
, were upregulated significantly in
VyMYB24
transgenic plants. These results indicate that
VyMYB24
plays a positive regulatory role in response to drought stress and also regulates plant development, which provides new evidence to further explore the molecular mechanism of drought stress of the MYB gene family.
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