Soil enzyme activities, soil physical properties, photosynthetic physical characteristics and water use of winter wheat after long-term straw mulch and organic fertilizer application.

Introduction: Inappropriate residue and nutrient management leads to soil degradation and the decline of soil quality and water storage capacity. Methods: An ongoing field experiment has been conducted since 2011 to investigate the effects of straw mulching (SM), and straw mulching combined with organic fertilizer (SM+O), on winter wheat yield, including a control treatment (CK, no straw). We studied the effects of these treatments on soil microbial biomass nitrogen and carbon, soil enzyme activity in 2019, photosynthetic parameters, evapotranspiration (ET), water use efficiency (WUE), and yields over five consecutive years (2015-2019). We also analyzed the soil organic carbon, soil structure, field capacity, and saturated hydraulic conductivity in 2015 and 2019. Results: Results indicate that compared with CK, SM and SM+O treatments increased the proportion of >0.25mm aggregates, soil organic carbon, field capacity, and saturated hydraulic conductivity, but decreased the soil bulk density. In addition, the SM and SM+O treatments also increased soil microbial biomass nitrogen and carbon, the activity of soil enzymes, and decreased the carbon-nitrogen ratio of microbial biomass. Therefore, SM and SM+O treatments both increased the leaf water use efficiency (LWUE) and photosynthetic rate (Pn), and improved the yields and water use efficiency (WUE) of winter wheat. The combination SM (4.5 t/ha)+O (0.75 t/ha) was more effective than SM alone, and both treatments were superior to the control. Conclusion: Based on the results of this study, SM+O is recommended as the most effective cultivation practice.

Drought-induced root aerenchyma formation restricts water uptake in rice seedlings supplied with nitrate.

Previous studies demonstrated that ammonium nutrition results in higher water uptake rate than does nitrate nutrition under water stress, and thus enhances the tolerance of rice plants to water stress. However, the process by which water uptake is related to nitrogen form under water stress remains unknown. A hydroponic experiment with simulated water stress induced by polyethylene glycol (PEG6000) was conducted in a greenhouse to study the relationship between root aerenchyma formation and water uptake rate, such as xylem sap flow rate and hydraulic conductance, in two different rice cultivars (cv. 'Shanyou 63' hybrid indica and cv. 'Yangdao 6' indica, China). The results showed that root aerenchyma tissue increased in water-stressed plants of both cultivars fed by nitrate. No significant difference was found in root hydraulic conductivity and/or xylem sap flow rate between the two rice cultivars fed by ammonium regardless of water status, whereas these parameters decreased significantly in water-stressed plants fed by nitrate. It was concluded that aerenchyma that formed in the root cortex impeded the radial transport of water in the root cylinder and decreased water uptake in water-stressed rice plants fed by nitrate. Water transport occurred mainly through Hg-sensitive water channels in rice roots supplied with ammonium.

Effect of long term application of super absorbent polymer on soil structure, soil enzyme activity, photosynthetic characteristics, water and nitrogen use of winter wheat.

Introduction: Water scarcity and seasonal drought are major constraints on agricultural development globally. Super absorbent polymer (SAP) is a good amendment that can improve soil structure, increase soil water retention, and promote crop growth even with less soil moisture. We hypothesize that long term application of SAP has a better effect on soil organic carbon, soil enzyme activity, photosynthetic characteristics, yield, and water and nitrogen use than short term application. Methods: A long term field experiment with different application rates (0 (CK), 15 (L), 30 (M), 45 (H) kg ha-1) of SAP was conducted at the Yuzhou water conservation agriculture base of the Henan Academy of Agricultural Sciences from 2011 to 2019. Results and Discussion: The results indicate that applying SAP increases > 0.25 mm aggregates and decreased<0.25 mm aggregates in the soil after one year (2011) and 9 years (2019) of application. In addition, soil organic carbon, soil microbial biomass carbon, soil sucrase and cellulase activities, soil water consumption, water consumption, net photosynthetic rate (Pn), leaf water use efficiency (LWUE) of wheat and yield, all increased after SAP application. SAP also boosts water use efficiency and nitrogen use efficiency. Correlation analyses show that SAP promotes the growth of wheat, and improves the utilization rate of soil water and nutrients by improving the soil structure and increasing soil organic carbon and microbial enzyme activity. Conclusion: Based on our research, SAP treatment at a dosage of 45 kg ha-1 is most effective and is thus recommended.

Impact of Combining Long-Term Subsoiling and Organic Fertilizer on Soil Microbial Biomass Carbon and Nitrogen, Soil Enzyme Activity, and Water Use of Winter Wheat.

Reductions in soil productivity and soil water retention capacity, and water scarcity during crop growth, may occur due to long-term suboptimal tillage and fertilization practices. Therefore, the application of appropriate tillage (subsoiling) and fertilization (organic fertilizer) practices is important for improving soil structure, water conservation and soil productivity. We hypothesize that subsoiling tillage combined with organic fertilizer has a better effect than subsoiling or organic fertilizer alone. A field experiment in Henan, China, has been conducted since 2011 to explore the effects of subsoiling and organic fertilizer, in combination, on winter wheat (Triticum aestivum L.) farming. We studied the effects of conventional tillage (CT), subsoiling (S), organic fertilizer (OF), and organic fertilizer combined with subsoiling (S+OF) treatments on dry matter accumulation (DM), water consumption (ET), water use efficiency (WUE) at different growth stages, yield, and water production efficiency (WPE) of winter wheat over 3 years (2016-2017, 2017-2018, 2018-2019). We also analyzed the soil structure, soil organic carbon, soil microbial biomass carbon and nitrogen, and soil enzymes in 2019. The results indicate that compared with CT, the S, OF and S+OF treatments increased the proportion of >0.25 mm aggregates, and S+OF especially led to increased soil organic carbon, soil microbial biomass carbon and nitrogen, soil enzyme activity (sucrase, cellulose, and urease). S+OF treatment was most effective in reducing ET, and increasing DM and WUE during the entire growth period of wheat. S+OF treatment also increased the total dry matter accumulation (Total DM) and total water use efficiency (total WUE) by 18.6-32.0% and 36.6-42.7%, respectively, during these 3 years. Wheat yield and WPE under S+OF treatment increased by 11.6-28.6% and 26.8-43.6%, respectively, in these 3 years. Therefore, S+OF in combination was found to be superior to S or OF alone, which in turn yielded better results than the CT.

Effect of ticagrelor on acute kidney injury in septic rats and its underlying mechanism.

The aim of the present study was to determine whether the effects and underlying mechanisms of ticagrelor in a rat model of sepsis-induced acute kidney injury (AKI) were mediated via the CD62P pathway. A total of 15 rats were randomly assigned to the following groups: Normal, sham, cecal ligation and puncture (CLP), CLP + clinical dose of ticagrelor (CCD) and CLP + loading dose of ticagrelor (CLD). Ticagrelor was administered 12 h before modeling, immediately after modeling, and 12 h after modeling at a dose of 8.6 and 46.42 mg/kg in the CCD and CLD groups, respectively. Rats in the normal, sham and CLP groups were treated with the same volume of distilled water. Serum creatinine (SCr), CD62P and interleukin-1ß (IL-1ß) levels, myeloperoxidase (MPO) activity in the renal tissue and the apoptosis rate of renal cells were increased in the CLP group, compared with in the normal and sham groups (P<0.05). In addition, ticagrelor treatment reduced SCr, CD62P and IL-1ß expression levels, renal tissue MPO activity and renal cell apoptosis in rats with sepsis-induced AKI (P<0.05). CD62P expression was closely associated with the occurrence of sepsis-induced AKI. The mechanism of ticagrelor-mediated reductions in inflammation, renal neutrophil infiltration and renal cell apoptosis is possibly associated with reductions in CD62P expression.

High water uptake ability was associated with root aerenchyma formation in rice: Evidence from local ammonium supply under osmotic stress conditions.

Root water uptake is strongly influenced by the morphology and anatomical structure of roots, which are regulated by nitrogen forms and environmental stimuli. To further illustrate the roles of different nitrogen forms on root water uptake under osmotic stress, a split-root system was supplied with different nitrogen forms and osmotic stress simulated by adding 10% (w/v) polyethylene glycol (PEG, 6000). The local effects of nitrogen form and osmotic stress on root morphology, anatomical structure, root lignin content, and water uptake rate were investigated. Under osmotic stress conditions, ammonium markedly promoted the formation and elongation of the lateral root, whereas a significant decrease in numbers of lateral roots was observed under local nitrate supply. Under nitrate supply in split-root systems, osmotic stress significantly promoted root cell death and more aerenchyma formation, as well as accelerated the lignification of the root. However, osmotic stress had no negative effect on the root anatomical structure under ammonium supply. The root water uptake rate was significantly higher in split-root supplied with ammonium than nitrate under osmotic stress conditions. In conclusion, the high water uptake ability in local ammonium supply was associated with the more lateral roots development and the lower cell death, aerenchyma formation and lignification under osmotic stress.

A case report of giant hamartoma of both kidneys with spontaneous rupture and hemorrhage in a pregnant woman: A case report.

The aim of the present study was to describe a case of renal angiomyolipoma (RAML) in a 31-year-old woman who presented with massive hemorrhage, shock, severe anemia (Hb 63 g-l) and multiple lesions, prior to delivery of a dead fetus. A 31-year-old woman was admitted due to left flank and abdominal pain at 20 weeks of gestation age, and diagnosed with RAML complicated with spontaneous rupture and hemorrhage of the left kidney, for which emergency exploratory laparotomy, left kidney resection and splenectomy were performed. The patient delivered a dead fetus 3 days following surgery and recovered well postoperatively. Hemorrhagic RAML during pregnancy is a rare and complex vascular surgical emergency, and should be managed in a multidisciplinary manner. Spontaneous rupture is a serious threat to the life and health of pregnant women and fetuses. The present case is a typical example of RAML in a pregnant woman complicated by spontaneous rupture and hemorrhage, which highlights the importance of determining the risk of acute hemorrhage in early stages of pregnancy, and the significance of time and proper management. However, in cases of shock caused by spontaneous rupture and hemorrhage, the only way to save the life of the patient is to resect the lesion without delay.

Nitrate increases ethylene production and aerenchyma formation in roots of lowland rice plants under water stress.

Ethylene increases root cortical aerenchyma formation in maize (Zea mays L.), rice (Oryza sativa L.) and other species. To further investigate the effects of nitrate, ammonium and water stress on ethylene production and aerenchyma formation in roots, two lowland rice cultivars (Shanyou 63, hybrid indica, and Yangdao 6, inbred indica) were cultured hydroponically with 10% (w/v) polyethylene glycol to simulate water stress. Water stress decreased shoot biomass, stomatal conductivity and leaf water potential in cultivars fed with nitrate but not with ammonium. Water stress induced more aerenchyma formation in cultivars fed with nitrate rather than ammonium, and increased cortical aerenchyma was found in Yangdao 6. Endogenous ethylene production by roots increased significantly under water stress in plants fed with nitrate rather than ammonium. Exogenous ethylene stimulated root cortical aerenchyma formation. Expression of the ethylene biosynthesis gene 1-aminocyclo-propane-1-carboxylic acid (ACC) synthase (ACS5) was greater in roots fed with nitrate rather than ammonium in the presence and absence of water stress. The expression of ethylene signalling pathway genes involved in programmed cell death (lesion-simulating disease (L.S.D.)1.1 and L.S.D.2; enhanced disease susceptibility (EDS) and phytoalexin-deficient (PAD4)) were regulated by the N form and water stress. In plants of cultivars fed with ammonium, L.S.D.1.1 expression increased under water stress, whereas L.S.D.2, EDS and PAD4 expression decreased. In conclusion, nitrate increases ethylene production and cortical aerenchyma formation in roots of water-stressed lowland rice. However, ammonium increased L.S.D.1.1 expression in water-stressed roots, and decreased ACS5, EDS and PAD4 expression, which would inhibit ethylene production and aerenchyma formation.

The enhanced drought tolerance of rice plants under ammonium is related to aquaporin (AQP).

Previously, we demonstrated that drought resistance in rice seedlings was increased by ammonium (NH4(+)) treatment, but not by nitrate (NO3(-)) treatment, and that the change was associated with root development. To study the effects of different forms of nitrogen on water uptake and root growth under drought conditions, we subjected two rice cultivars (cv. 'Shanyou 63' hybrid indica and cv. 'Yangdao 6' indica, China) to polyethylene glycol-induced drought stress in a glasshouse using hydroponic culture. Under drought conditions, NH4(+) significantly stimulated root growth compared to NO3(-), as indicated by the root length, surface area, volume, and numbers of lateral roots and root tips. Drought stress decreased the root elongation rate in both cultivars when they were supplied with NO3(-), while the rate was unaffected in the presence of NH4(+). Drought stress significantly increased root protoplast water permeability, root hydraulic conductivity, and the expression of root aquaporin (AQP) plasma intrinsic protein (PIP) genes in rice plants supplied with NH4(+); these changes were not observed in plants supplied with NO3(-). Additionally, ethylene, which is involved in the regulation of root growth, accumulated in rice roots supplied with NO3(-) under conditions of drought stress. We conclude that the increase in AQP expression and/or activity enhanced the root water uptake ability and the drought tolerance of rice plants supplied with NH4(+).