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[Objective] The aims of this study are to explore the response characteristics of soil physical and chemical properties and stoichiometric characteristics to stand density of Robinia pseudoacacia and Pinus tabuliformis plantations in loess hilly region, and to provide scientific basis for plantation management in loess hilly region. [Methods] The soil bulk density, water content, soil organic carbon（SOC）, total nitrogen（TN） and total phosphorus（TP） contents of two plantations were measured and analyzed. The variation characteristics and vertical variation characteristics of each index with different density gradients were studied by single factor variance analysis method, and the correlation between each index was analyzed by multi-factor correlation analysis method. [Results]（1） In the vertical distribution characteristics, the SOC and TN contents of each stand showed a significant decreasing trend with the increase of soil depth. There was no significant difference in soil bulk density and TP content.（2） Robinia pseudoacacia forest density had no significant effect on soil bulk density, water content, N∶P and other indicators. SOC, TN, TP and C∶N of low density Robinia pseudoacacia forest were significantly higher than those of other densities.（3） Pinus tabulaeformis forest density had no significant effect on soil bulk density, C∶N, C∶P, N∶P and other indicators. The contents of SOC, TN and TP in high density pine forest were significantly higher than those in other density pine forest.（4） Under the same density, the soil bulk density and water content of Robinia pseudoacacia forest were higher than those of Pinus tabulaeformis forest. The SOC, TN, C∶N, C∶P, N∶P were lower than those of Pinus tabulaeformis forest, except for C∶N, the differences were significant. [Conclusion] The contents of SOC, TN and TP in low-density Robinia pseudoacacia forest were higher, while the contents of SOC, TN and TP in high-density Pinus tabulaeformis forest were higher, and the soil quality of Pinus tabulaeformis forest was relatively better than that of Robinia pseudoacacia forest. [ABSTRACT FROM AUTHOR]

Tuber of Pinellia cordata has been the extensively used as medicines in the practice of traditional Chinese medicine. Bulbil formation is the main propagation strategy of P. cordata in wild. There are two developmental stages of bulbils for each one individual: on the basis of leaf blade (upper bulbil) and on the lower part of petiole (lower bulbil). To reveal the developmental characteristics of bulbil formation in P. cordata, morphological and anatomical observation were systematically used. Morphological observation showed that the whole development process of upper or lower bulbil could be divided three stages: no visible bulbil structure, primary bulbil formation under epidermis, growth and maturation of bulbil. Correspondingly, anatomical observation showed that the whole development process of upper or lower bulbil could be divided four stages: initial cell formation, bulbil promodia formation, differentiation of bulbil, and bulbil growth continuously to maturation. The initial cell of bulbil was derived or dedifferentiated from the parenchyma cell which was located in the adaxial side of young petiole. Initial cell formation was not visible. Continuously division of the initial parenchyma cell resulted in the formation of bulbil primodium, which was a group of undifferentiated cell. The primordium continuously growth and then differentiated to form the shoot apical meristem (SAM), which was the infant bulbil on the adaxial side. Bulbil promodium formation and early primodium differentiation could be visible with white dot structure on petiole. Subsequently, differentiated bulbil growth and lateral scale leaf differentiation continuously characterized the bulbil growth stage. Bulbil growth terminated with the leaf senescence. The average diameter of maturated upper bulbil on blade and lower bulbil on petiole were (2.79 ± 0.40) mm and (2.69 ± 0.36) mm, respectively. The maturated bulbils generally were gray and ellipsoidal, and shaped with various number of external scale leaf. The inner cells of maturated bulbil contained lots of nutrients (storage). The germination rate of bulbils was up to 75% in soil culture. Morphological and anatomical observation results indicate that the development of bulbils in P. cordata is the same in P. ternata, and the development of bulbil in P. cordata is an effective reproduction strategy just like in P. ternata. [ABSTRACT FROM AUTHOR]

Objective To investigate the protective effect of Platycodin D (PD) on renal ischemia-reperfusion injury in rats. Methods The rats were divided into sham group, model group, low, middle and high-dose groups with 10 animals in each. The rat model of ischemia reperfusion injury was established by clamping the bilateral renal pedicles in model group, low, middle and high-dose group. The rats in sham group underwent the same modeling operation but did not clamp the renal pedicles. Before 5 minutes of modeling, the rats of low, middle and high-dose group were intra-peritoneally injected with 12.5, 25 and 50 mg/kg PD, respectively. After 24 h of modeling, the serum creatinine (Cr) and blood urea nitrogen (BUN) levels, as well as antioxidant markers[superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) ] levels in kidney tissues were measured. HE staining was used to evaluate renal tissue lesions. Immuno-histochemical staining was used to detect the expression of caspase-3 in renal tissue, the apoptosis index of renal tubular epithelial cells was evaluated by the counting of caspase-3 positive cells. RT-qPCR was used to detect the expression of interleukin-1β (IL-1β), IL-6 and IL-10 mRNA in renal tissues. Western blot was used to detect the expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), p65, p-p65, inhibitor of nuclear factor kappa B (NF-κB) (IκB) and p-IκB. Results Compared with sham group, the kidney lesions, serum Cr and BUN levels, apoptosis index of renal tubular epithelial cells in model group were all increased (P＜0.05) . Compared with model group, the kidney lesions, serum Cr and BUN levels, apoptosis index of renal tubular epithelial cells in low, middle and high-dose group were decreased (P＜0.05) . Compared with sham group, the level of MDA and mRNA of IL-1β and IL-6, the protein expression of TLR4/MyD88/NF-κB signaling pathway in kidney tissue in model group were all significantly increased while the level of SOD and GSH-Px and mRNA of IL-10 in rat kidney tissue were decreased (P＜0.05) . Compared with model group, the level of MDA, mRNA of IL-1β and IL-6, the protein expression of TLR4/MyD88/NF-κB signaling pathway in kidney tissue in low, middle and high-dose group were all decreased, SOD and GSH-Px and IL-10 mRNA in rat kidney tissue were increased (P＜0.05) . Conclusions Platycodin D has a protective effect on renal ischemia-reperfusion injury in rats, and the underlying mechanism may be related to the improvement of antioxidant capacity and inhibition of TLR4/MyD88/NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]