A Myb Transcription Factor of Phytophthora sojae, Regulated by MAP Kinase PsSAK1, Is Required for Zoospore Development

PsSAK1, a mitogen-activated protein (MAP) kinase from Phytophthora sojae, plays an important role in host infection and zoospore viability. However, the downstream mechanism of PsSAK1 remains unclear. In this study, the 3'-tag digital gene expression (DGE) profiling method was applied to sequence the global transcriptional sequence of PsSAK1-silenced mutants during the cysts stage and 1.5 h after inoculation onto susceptible soybean leaf tissues. Compared with the gene expression levels of the recipient P. sojae strain, several candidates of Myb family were differentially expressed (up or down) in response to the loss of PsSAK1, including of a R2R3-type Myb transcription factor, PsMYB1. qRT-PCR indicated that the transcriptional level of PsMYB1 decreased due to PsSAK1 silencing. The transcriptional level of PsMYB1 increased during sporulating hyphae, in germinated cysts, and early infection. Silencing of PsMYB1 results in three phenotypes: a) no cleavage of the cytoplasm into uninucleate zoospores or release of normal zoospores, b) direct germination of sporangia, and c) afunction in zoospore-mediated plant infection. Our data indicate that the PsMYB1 transcription factor functions downstream of MAP kinase PsSAK1 and is required for zoospore development of P. sojae

Plastic failure zone characteristics and stability control technology of roadway in the fault area under non-uniformly high geostress: A case study from Yuandian Coal Mine in Northern Anhui Province, China

In order to explore the effective support method for deep broken roadway, based on the in situ stress test results, the analytical and numerical solutions of the stress and the range of plastic failure zone (PFZ) in a circular roadway subjected to non-uniform loads were obtained using analytical and finite difference numerical methods based on the elastoplastic theory, respectively. Their comparison results show that the analytical and numerical methods are correct and reasonable. Furthermore, the high geostress causes the stress and range of PFZ in roadway roof and floor to increase sharply while those in roadway ribs decrease. Moreover, the greater the difference of horizontal geostress in different horizontal directions is, the larger the range of PFZ in roadway roof and floor is. The shape of PFZ in roadway varies with the ratio of horizontal lateral pressure coefficient in x-direction and y-direction. Finally, according to the distribution characteristics of PFZ and range of PFZ under the non-uniformly high geostress, this paper has proposed a combined support scheme, and refined and optimized supporting parameters. The field monitoring results prove that the roadway deformation and fracture have been effectively controlled. The research results of this paper can provide theoretical foundation as well as technical reference for the stability control of deep broken roadway under non-uniformly high geostress

Shear Strength and Re-Failure Characteristics of Intact Red Sandstone and Grouting-Reinforced Body of Fractured Red Sandstone under Different Shear Angles

To reveal the strengthening mechanism and re-failure mechanism of grouting on fractured rock, the variable-angle shear tests, real-time acoustic emission (AE) tests and VIC-3D (non-contact full field strain measurement system) tests were carried out on intact red sandstone (IRS) and grouting-reinforced body of fractured red sandstone (GRBFRS). The results show that the peak shear strength of IRS and GRBFRS decreases with the increase of shear angle. Grouting reinforcement mainly increases the cohesion of GRBFRS to improve its shear strength, but its reconstructability decreases with the increase of shear angle. In the whole process of shear deformation, the shear micro damage and shear fracture of GRBFRS are more than those of IRS. Although the shear re-failure before and after the peak stress stage is the most notable, its intensity or degree is reduced. When the shear angle is 45°, both IRS and GRBFRS undergo shear-splitting failure. However, when the shear angle is large, the IRS and GRBFRS only occurs shear failure. Moreover, the larger the shear angle, the more likely IRS and GRBFRS is to produce secondary shear cracks. The low strength of the rock–grout interface in GRBFRS is the main inducer of shear re-failure

Shear Strength and Re-Failure Characteristics of Intact Red Sandstone and Grouting-Reinforced Body of Fractured Red Sandstone under Different Shear Angles

To reveal the strengthening mechanism and re-failure mechanism of grouting on fractured rock, the variable-angle shear tests, real-time acoustic emission (AE) tests and VIC-3D (non-contact full field strain measurement system) tests were carried out on intact red sandstone (IRS) and grouting-reinforced body of fractured red sandstone (GRBFRS). The results show that the peak shear strength of IRS and GRBFRS decreases with the increase of shear angle. Grouting reinforcement mainly increases the cohesion of GRBFRS to improve its shear strength, but its reconstructability decreases with the increase of shear angle. In the whole process of shear deformation, the shear micro damage and shear fracture of GRBFRS are more than those of IRS. Although the shear re-failure before and after the peak stress stage is the most notable, its intensity or degree is reduced. When the shear angle is 45°, both IRS and GRBFRS undergo shear-splitting failure. However, when the shear angle is large, the IRS and GRBFRS only occurs shear failure. Moreover, the larger the shear angle, the more likely IRS and GRBFRS is to produce secondary shear cracks. The low strength of the rock–grout interface in GRBFRS is the main inducer of shear re-failure

Value of placental virtual magnetic resonance elastography and intravoxel incoherent motion-based diffusion and perfusion in predicting adverse outcomes of small-for-gestational-age infants

Abstract Objective It is critical to early monitor and manage small-for-gestational age (SGA) infants with truly adverse outcomes not detected by conventional methods. We aimed to explore the value of diffusion-weighted imaging (DWI)-based virtual magnetic resonance elastography (vMRE) and intravoxel incoherent motion (IVIM)-based biexponential and stretched exponential parameters in predicting adverse outcomes of SGA infants. Methods Twenty SGA infants with adverse outcomes and forty without adverse outcomes were included in this prospective study. One DWI-based vMRE parameter [the stiffness value (μ diff)], five IVIM–based parameters [true diffusion coefficient (D), pseudo-diffusion coefficient (D * ), perfusion fraction (f), diffusion distribution coefficient (DDC), and diffusion heterogeneity index (Alpha)] and apparent diffusion coefficient (ADC) were calculated and compared between groups. The predictive efficiency was compared by the logistic regression analysis and receiver operating characteristic curve analysis. The relationship between the μ diff value with gestational age was also evaluated. Results The placental μ diff value was remarkably higher, and the f, DDC, and ADC values were considerably lower in the SGA infants with adverse outcomes compared with those without adverse outcomes. The μ diff and f value were predictive risk factors for SGA infants with adverse outcomes. A combined predictive model (μ diff and f) improved the predictive efficacy. Moreover, there was no statistically significant correlation between the placental stiffness value and gestational age. Conclusions Functional MRI parameters to quantify placenta elastography and microcirculation in SGA patients. This might be a useful tool to assess placental function and a vital non-invasive supplement for predicting adverse outcomes of SGA infants. Critical relevance statement This prospective study shows DWI-based virtual magnetic resonance elastography and intravoxel incoherent motion-based functional parameters to quantify placenta elastography and microcirculation in small-for-gestational-age patients, which could complement existing non-invasive methods for monitoring and predicting neonatal perinatal adverse outcome. Key points • vMRE is an emerging non-invasive imaging technique for evaluating placenta stiffness. • SGA infants with adverse outcome have stiffer placental elasticity and lower microcirculation. • Risk factors combination displayed better efficacy in predicting adverse outcomes of SGA. Graphical Abstrac

Transcriptome Analysis and Screening of Genes Associated with Flower Size in Tomato (Solanum lycopersicum)

Flower development is not only an important way for tomato reproduction but also an important guarantee for tomato fruit production. Although more and more attention has been paid to the study of flower development, there are few studies on the molecular mechanism and gene expression level of tomato flower development. In this study, RNA-seq analysis was performed on two stages of tomato flower development using the Illumina sequencing platform. A total of 8536 DEGs were obtained by sequencing, including 3873 upregulated DEGs and 4663 down-regulated DEGs. These differentially expressed genes are related to plant hormone signaling, starch and sucrose metabolism. The pathways such as pentose, glucuronate interconversion, and Phenylpropanoid biosynthesis are closely related and mainly involved in plant cellular and metabolic processes. According to the enrichment analysis results of DEGs, active energy metabolism can be inferred during flower development, indicating that flower development requires a large amount of energy and material supply. In addition, some plant hormones, such as GA, may also have effects on flower development. Combined with previous studies, the expression levels of Solyc02g087860 and three of bZIPs were significantly increased in the full flowering stage compared with the flower bud stage, indicating that these genes may be closely related to flower development. These genes were previously reported in Arabidopsis but not in tomatoes. Our next work will conduct a detailed functional analysis of the identified bZIP family genes to characterize their association with tomato flower size. This study will provide new genetic resources for flower formation and provide a basis for tomato yield breeding