Deformation Law and Spatial Effect of Deep Foundation Pits for Subway Construction in Soil-Rock Composite Strata in Seasonally Frozen Areas

The stability and safety of metro deep foundation pit in the soil-rock composite stratum in the seasonally frozen area are the key issues in the design and construction of the foundation pit. In order to ensure the soil-rock composite stratum in the seasonally frozen area, the deformation of the supporting structure is within the safe range when the deep foundation pit is excavated. At the same time, it will reduce the impact of the construction of metro deep foundation pit on the surrounding buildings. During the construction of foundation pit, close monitoring shall be carried out and the actual monitoring data shall be studied and analyzed. During the excavation of each layer of the foundation pit, monitor the displacement change of the foundation pit support structure and the settlement change of the surrounding ground surface, study the deformation law of the subway deep foundation pit in the soil-rock composite layer, and discuss the spatial effect of the foundation pit excavation in the seasonally frozen area. This paper mainly takes the deep foundation pit project of Anxin Road Station of Changchun Metro Line 5 as the research object, and analyzes the actual monitoring results. The results show that: (1) With the long side of the foundation pit, the deformation of the retaining structure of the foundation pit increases with the distance from the pit corner, and the middle of the long side of the foundation pit is less constrained by the retaining structure. (2) During the excavation of soil-rock composite foundation pit in seasonally frozen soil area, the pile displacement, axial force of support and uplift of support structure caused by rock excavation are relatively small, while the lateral displacement of foundation pit below the rock surface and thawing settlement deformation of soil are basically unchanged. The maximum lateral displacement of the foundation pit at the upper part of the rock surface moves upward. During the construction of deep foundation pit, there is a large displacement before the erection of the third layer of steel support. Attention should be paid to the soil properties of the deep silty clay layer, as well as to the rapid construction and synchronous maintenance

Metabolic Profiles and cDNA-AFLP Analysis of Salvia miltiorrhiza and Salvia castanea Diel f. tomentosa Stib

Plants of the genus Salvia produce various types of phenolic compounds and tanshinones which are effective for treatment of coronary heart disease. Salvia miltiorrhiza and S. castanea Diels f. tomentosa Stib are two important members of the genus. In this study, metabolic profiles and cDNA-AFLP analysis of four samples were employed to identify novel genes potentially involved in phenolic compounds and tanshinones biosynthesis, including the red roots from the two species and two tanshinone-free roots from S. miltiorrhiza. The results showed that the red roots of S. castanea Diels f. tomentosa Stib produced high contents of rosmarinic acid (21.77 mg/g) and tanshinone IIA (12.60 mg/g), but low content of salvianolic acid B (1.45 mg/g). The red roots of S. miltiorrhiza produced high content of salvianolic acid B (18.69 mg/g), while tanshinones accumulation in this sample was much less than that in S. castanea Diels f. tomentosa Stib. Tanshinones were not detected in the two tanshinone-free samples, which produced high contents of phenolic compounds. A cDNA-AFLP analysis with 128 primer pairs revealed that 2300 transcript derived fragments (TDFs) were differentially expressed among the four samples. About 323 TDFs were sequenced, of which 78 TDFs were annotated with known functions through BLASTX searching the Genbank database and 14 annotated TDFs were assigned into secondary metabolic pathways through searching the KEGGPATHWAY database. The quantitative real-time PCR analysis indicated that the expression of 9 TDFs was positively correlated with accumulation of phenolic compounds and tanshinones. These TDFs additionally showed coordinated transcriptional response with 6 previously-identified genes involved in biosynthesis of tanshinones and phenolic compounds in S. miltiorrhiza hairy roots treated with yeast extract. The sequence data in the present work not only provided us candidate genes involved in phenolic compounds and tanshinones biosynthesis but also gave us further insight into secondary metabolism in Salvia

Isolation and Characterization of a Phosphorus-Solubilizing Bacterium from Rhizosphere Soils and Its Colonization of Chinese Cabbage (Brassica campestris ssp. chinensis)

Phosphate-solubilizing bacteria (PSB) can promote the dissolution of insoluble phosphorus (P) in soil, enhancing the availability of soluble P. Thus, their application can reduce the consumption of fertilizer and aid in sustainable agricultural development. From the rhizosphere of Chinese cabbage plants grown in Yangling, we isolated a strain of PSB (YL6) with a strong ability to dissolve P and showed that this strain promoted the growth of these plants under field conditions. However, systematic research on the colonization of bacteria in the plant rhizosphere remains deficient. Thus, to further study the effects of PSB on plant growth, in this study, green fluorescent protein (GFP) was used to study the colonization of YL6 on Chinese cabbage roots. GFP expression had little effect on the ability of YL6 to grow and solubilize P. In addition, the GFP-expressing strain stably colonized the Chinese cabbage rhizosphere (the number of colonizing bacteria in the rhizosphere soil was 4.9 lg CFU/g). Using fluorescence microscopy, we observed a high abundance of YL6-GFP bacteria at the Chinese cabbage root cap and meristematic zone, as well as in the root hairs and hypocotyl epidermal cells. High quantities of GFP-expressing bacteria were recovered from Chinese cabbage plants during different planting periods for further observation, indicating that YL6-GFP had the ability to endogenously colonize the plants. This study has laid a solid and significant foundation for further research on how PSB affects the physiological processes in Chinese cabbage to promote plant growth

Cloning and characterization of a putative R2R3 MYB transcriptional repressor of the rosmarinic acid biosynthetic pathway from Salvia miltiorrhiza.

Salvia miltiorrhiza Bunge is one of the most renowned traditional medicinal plants in China. Phenolic acids that are derived from the rosmarinic acid pathway, such as rosmarinic acid and salvianolic acid B, are important bioactive components in S. miltiorrhiza. Accumulations of these compounds have been reported to be induced by various elicitors, while little is known about transcription factors that function in their biosynthetic pathways. We cloned a subgroup 4 R2R3 MYB transcription factor gene (SmMYB39) from S. miltiorrhiza and characterized its roles through overexpression and RNAi-mediated silencing. As the results showed, the content of 4-coumaric acid, rosmarinic acid, salvianolic acid B, salvianolic acid A and total phenolics was dramatically decreased in SmMYB39-overexpressing S. miltiorrhiza lines while being enhanced by folds in SmMYB39-RNAi lines. Quantitative real-time PCR and enzyme activities analyses showed that SmMYB39 negatively regulated transcripts and enzyme activities of 4-hydroxylase (C4H) and tyrosine aminotransferase (TAT). These data suggest that SmMYB39 is involved in regulation of rosmarinic acid pathway and acts as a repressor through suppressing transcripts of key enzyme genes

Lipopolysaccharide Enhances Tanshinone Biosynthesis via a Ca2+-Dependent Manner in Salvia miltiorrhiza Hairy Roots

Tanshinones, the major bioactive components in Salvia miltiorrhiza Bunge (Danshen), are synthesized via the mevalonic acid (MVA) pathway or the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway and the downstream biosynthesis pathway. In this study, the bacterial component lipopolysaccharide (LPS) was utilized as a novel elicitor to induce the wild type hairy roots of S. miltiorrhiza. HPLC analysis revealed that LPS treatment resulted in a significant accumulation of cryptotanshinone (CT) and dihydrotanshinone I (DTI). qRT-PCR analysis confirmed that biosynthesis genes such as SmAACT and SmHMGS from the MVA pathway, SmDXS and SmHDR from the MEP pathway, and SmCPS, SmKSL and SmCYP76AH1 from the downstream pathway were markedly upregulated by LPS in a time-dependent manner. Furthermore, transcription factors SmWRKY1 and SmWRKY2, which can activate the expression of SmDXR, SmDXS and SmCPS, were also increased by LPS. Since Ca2+ signaling is essential for the LPS-triggered immune response, Ca2+ channel blocker LaCl3 and CaM antagonist W-7 were used to investigate the role of Ca2+ signaling in tanshinone biosynthesis. HPLC analysis demonstrated that both LaCl3 and W-7 diminished LPS-induced tanshinone accumulation. The downstream biosynthesis genes including SmCPS and SmCYP76AH1 were especially regulated by Ca2+ signaling. To summarize, LPS enhances tanshinone biosynthesis through SmWRKY1- and SmWRKY2-regulated pathways relying on Ca2+ signaling. Ca2+ signal transduction plays a key role in regulating tanshinone biosynthesis in S. miltiorrhiza

Analysis of related phenolic compounds contents in transgenic lines and controls of <i>S. miltiorrhiza</i>.

<p>Data presented here are the mean of three replicates with error bars indicating ± SD. The asterisks indicate statistically significant differences (<i>P</i><<i>0.05</i>) compared to the empty vector control. control: untransformed plant; ox-VC, RNAi-VC: empty vector controls of <i>SmMYB39</i>-overexpressing lines and <i>SmMYB39</i>-RNAi lines; ox-3, ox-17, ox-28: <i>SmMYB39</i>-overexpressing lines; RNAi-11, RNAi-19, RNAi-25: <i>SmMYB39</i>-RNAi lines.</p

Phenolic acids biosynthetic pathway in <i>S. miltiorrhiza</i>.

<p>Multiple enzymatic steps are represented by dotted lines. The ‘circle’ and ‘square’ are used to distinguish between the downstream pathway of RA and other branches of phenylpropanes metabolism. C3H, coumarate 3-hydroxylase; C4H, cinnamic acid 4-hydroxylase; 4CL, 4-coumaric acid CoA-ligase; COMT, caffeic acid O-methyltransferase; HPPR, 4-hydroxyphenylpyruvate reductase; PAL, phenylalanine ammonia-lyase; RAS, rosmarinic acid synthase; TAT, tyrosine aminotransferase.</p

Relative quantitative transcripts analysis of enzyme genes in transgenic lines and controls of <i>S. miltiorrhiza</i>.

<p>The results were analyzed using the comparative Ct method and presented as fold-changes compared with the control sample (untransformed control). The <i>S. miltiorrhiza actin</i> gene was used as an internal control to normalize expression levels. The asterisks indicate statistically significant differences (<i>P</i><<i>0.05</i>) compared to the empty vector control. control: untransformed plant; ox-VC, RNAi-VC: empty vector controls of <i>SmMYB39</i>-overexpressing lines and <i>SmMYB39</i>-RNAi lines; ox-3, ox-17, ox-28: <i>SmMYB39</i>-overexpressing lines; RNAi-11, RNAi-19, RNAi-25: <i>SmMYB39</i>-RNAi lines; <i>PAL</i>: phenylalanine ammonia-lyase; <i>C4H</i>: cinnamic acid 4-hydroxylase; <i>4CL</i>: 4-coumaric acid CoA-ligase; <i>TAT</i>: tyrosine aminotransferase; <i>HPPR</i>: 4-hydroxyphenylpyruvate reductase.</p

Enzyme activities analysis of C4H and TAT in transgenic lines and controls of <i>S. miltiorrhiza</i>.

<p>Data presented here are the mean of three replicates with error bars indicating ± SD. The asterisks indicate statistically significant differences (<i>P</i><<i>0.05</i>) compared to the empty vector control. control: untransformed plant; ox-VC, RNAi-VC: empty vector controls of <i>SmMYB39</i>-overexpressing lines and <i>SmMYB39</i>-RNAi lines; ox-3, ox-17, ox-28: <i>SmMYB39</i>-overexpressing lines; RNAi-11, RNAi-19, RNAi-25: <i>SmMYB39</i>-RNAi lines; C4H: cinnamic acid 4-hydroxylase; TAT: tyrosine aminotransferase.</p