Zinc regulation of chlorophyll fluorescence and carbohydrate metabolism in saline-sodic stressed rice seedlings.

Saline-sodic stress can limit the absorption of available zinc in rice, subsequently impacting the normal photosynthesis and carbohydrate metabolism of rice plants. To investigate the impact of exogenous zinc application on photosynthesis and carbohydrate metabolism in rice grown in saline-sodic soil, this study simulated saline-sodic stress conditions using two rice varieties, 'Changbai 9' and 'Tonghe 899', as experimental materials. Rice seedlings at 4 weeks of age underwent various treatments including control (CT), 2 µmol·L-1 zinc treatment alone (Z), 50 mmol·L-1 saline-sodic treatment (S), and 50 mmol·L-1 saline-sodic treatment with 2 µmol·L-1 zinc (Z + S). We utilized JIP-test to analyze the variations in excitation fluorescence and MR820 signal in rice leaves resulting from zinc supplementation under saline-sodic stress, and examined the impact of zinc supplementation on carbohydrate metabolism in both rice leaves and roots under saline-sodic stress. Research shows that zinc increased the chloroplast pigment content, specific energy flow, quantum yield, and performance of active PSII reaction centers (PIABS), as well as the oxidation (VOX) and reduction rate (Vred) of PSI in rice leaves under saline-sodic stress. Additionally, it decreased the relative variable fluorescence (WK and VJ) and quantum energy dissipation yield (φDO) of the rice. Meanwhile, zinc application can reduce the content of soluble sugars and starch in rice leaves and increasing the starch content in the roots. Therefore, the addition of zinc promotes electron and energy transfer in the rice photosystem under saline-sodic stress. It enhances rice carbohydrate metabolism, improving the rice plants' ability to withstand saline-sodic stress and ultimately promoting rice growth and development.

Effect of Hypoxia on Self-Renewal Capacity and Differentiation in Human Tendon-Derived Stem Cells.

BACKGROUND Hypoxic conditions play roles in functioning of human tendon-derived stem cells (hTSCs). The goal of this study was to investigate the effect of various hypoxic conditions in self-renewal capacity and differentiation of TSCs. MATERIAL AND METHODS hTSCs was obtain from supraspinatus tendon donors. Colony formation and cell proliferation assay were used to assess the self-renewal of hTSCs. qRT-PCT and Western blot analysis were used to examine stemness and multi-differentiation potential of hTSCs. RESULTS We found that culturing at 5% O2 is more beneficial for the self-renewal of hTSCs than the other 3 culture conditions, with larger colony size and numbers. The proliferation of hTSCs in 5%, 10%, and 20% O2 cultures increased after seeding. The number of cells in the 5% O2 condition was higher than that in other culture; however, self-renewal capacity of hTSCs in 0.5% O2 was inhibited. The expression levels of stem cell markers, including NS, Nanog, Oct-4, and SSEA-4, were highest in 0.5% O2 culture. Furthermore, hTSCs cultured in 20% O2 exhibited significantly higher expression of the 3 markers (PPAR-γ, Sox-9, and Runx-2). CONCLUSIONS Hypoxic condition of culture encouraged self-renewal capacity of hTSCs, but inhibited their multi-differentiation potential, compared to normoxic condition of culture. Moreover, excessively low oxygen concentration impaired the capacity of hTSCs.

Parasitism and Suitability of Different Egg Ages of the Leguminivora glycinivorella (Lepidoptera: Tortricidae) for Three Indigenous Trichogramma Species.

Pod borers are economically important soybean pests in temperate and tropical regions. However, the biological control of these pests using their natural insect enemies has been poorly studied to date. Indigenous natural populations of three Trichogramma (Hymenoptera: Trichogrammatidae) species, Trichogramma chilonis Ishii, Trichogramma ostriniae Pang & Chen, and Trichogramma leucaniae Pang & Chen, were collected from Leguminivora glycinivorella (Matsumura) (Lepidoptera: Tortricidae) eggs in soybean fields in China. In this study, we compare the parasitic capacities and suitabilities of three indigenous Trichogramma species on L. glycinivorella eggs at various ages. Host eggs of all ages were accepted by T. chilonis, T. ostriniae, and T. leucaniae. T. chilonis tended to parasitize 0-2-d-old eggs more than 3-4-d-old eggs. There were no significant differences in parasitism between the 0-2-d-old eggs and the 1-4-d-old eggs for T. ostriniae and T. leucaniae. For eggs at various ages, T. chilonis parasitized the smallest number of eggs, while T. leucaniae and T. ostriniae exhibited similar parasitic capacities. With 0-d-old host eggs, T. ostriniae developed over the longest time period (8.7 d), and T. leucaniae produced the most female progeny (87.9%). Both T. leucaniae and T. ostriniae had similar developmental times, survival rates and percentages of female progeny with 1-3-d-old eggs. These results show that T. leucaniae can parasitize host eggs at varying ages with the best development and suggest that it may be a valuable biological control agent for soybean pod borers.

Effect of different concentrations of foliar iron fertilizer on chlorophyll fluorescence characteristics of iron-deficient rice seedlings under saline sodic conditions.

The effectiveness of iron is reduced in saline conditions, which can easily lead to iron deficiency and inhibit photosynthesis in rice. In this study, 4-week-old Fe-deficient rice seedlings were treated under saline sodic stress (50 mM) to different concentrations (0, 0.2%, 0.4%, 0.8%, 1.6%, and 3.2%) of foliar iron fertilizer (FeEDDHA). Differences in prompting fluorescence and the MR820 signal of rice leaves after 7 days of treatment were probed using the JIP-test. The results show that the performances of the two rice varieties were in general agreement. Under iron deficiency and soda salinity stress conditions, rice growth was inhibited, and the pigment content, specific energy flux, quantum yield, performance of the active PSII reaction center (PIABS) and the oxidation (Vox) and reduction rates (Vred) of PSI were reduced. These indicators first increase and then decrease with increasing iron fertiliser concentrations. The best results were obtained with the Fe3 treatment (0.8%). Fluorescence parameters such as the relative variable fluorescence (WK and VJ) and the quantum yield of energy dissipation (φDo) showed opposite trends. This suggests that iron deficiency/excess and soda saline stress disrupt the electron and energy transport in the photosystem. Appropriate iron fertilization concentration can repair the photosynthetic electron transport chain, improve electron transport efficiency and promote balanced energy distribution. Therefore, we suggest that moderate amounts of Fe are beneficial for improving the electron and energy transport properties of the photosystem, while spraying high concentrations of Fe fertilizer has a negative effect on improving salt tolerance in rice.

A simple method for lodging resistance evaluation of maize in the field.

The increase of planting density is a dominant approach for the higher yield of maize. However, the stalks of some varieties are prone to lodging under high density conditions. Much research has been done on the evaluation of maize lodging resistance. But there are few comprehensive reports on the determination of maize lodging resistance in situ without injury under field conditions. This study introduces a non-destructive in situ tester to determine the lodging resistance of the different maize varieties in the field. The force value can be obtained by pulling the stalk to different angles with this instrument, which is used to evaluate the lodging resistance of maize varieties. From 2018 to 2020, a total of 1,172 sample plants from 113 maize varieties were tested for the lodging resistance of plants. The statistical results show that the values of force on maize plants at 45° inclination angles (F45) are appropriate to characterize maize lodging resistance in situ by nondestructive testing in the field. According to the F45 value, the maximum lodging resistance Fmax can be inferred. The formula is: Fmax =1.1354 F45 - 0.3358. The evaluation results of lodging resistance of different varieties of this study are basically consistent with the test results of three-point bending method, moving wind tunnel and other methods. Therefore, the F45 value is the optimal index for nondestructive evaluation of maize stalk-lodging resistance under the field-planting conditions.

Insecticidal effect of aconitine on the rice brown planthoppers.

The brown planthopper, Nilaparvata lugens (Stål), severely damages rice production and develops high level resistance to several classes of insecticides. To find potential insecticidal resources is always important. As an environmentally friendly compound, aconitine exhibits potential pesticide features. In the present study, the pesticide and knockdown effects of aconitine were first tested on the brown planthopper. The results showed that the knockdown rates for an aconitine concentration of 200 ppm was 83.6%. The insecticidal LD50 was 22.68 ng/pest (95% CI, 17.75-28.99). The molecular mechanisms responding to aconitine application were analyzed through transcriptional sequencing. Compared to that of the knockdown nymphs of the brown planthoppers, the enzymes CYP3A4, UDP-glucuronosyltransferase (UGT), GST, carboxylesterase (EC3.1.1.1), and GABAergic synapse were up-regulated. We inferred that aconitine might be neurotoxic to the brown planthoppers, and the conscious nymphs resist the drug neurotoxicity through the upregulation of CYP3A4, UGT, and GABA receptor mutation. Although aconitine is not safe for mammals, it may be a leading compound to develop novel insecticides.

Distal tibial nonunion using a contralateral anterior L-shaped locking compression plate through a posterior-lateral approach: A retrospective case series.

BACKGROUND: Distal tibial nonunion is usually due to severe open distal tibial fractures with high energy injury. The best surgical treatment is not well established because of the poor soft tissue condition. We retrospectively analyzed a series of patients with distal tibial nonunion after severe open distal tibial fractures; our purpose was to introduce a treatment using a contralateral anterior L-shaped locking compression plate through a posterior-lateral approach with Iliac crest bone graft and evaluate the outcomes of patients. METHODS: All patients with distal tibial nonunion who received a contralateral anterior L-shaped locking compression plate fixation through the posterior-lateral approach with Iliac crest bone graft by a single surgeon from 2014 to 2016 were reviewed. 9 patients met the criteria. Five of nine patients had varus deformities (range, 9-40°) and 4 patients had valgus deformities (range, 5-30°). Postoperative radiographs, Postoperative complications, limb alignment and limb functional outcome information of AOFAS ankle-hindfoot score were recorded. RESULTS: All patients were followed up for at least 8 months (range, 8-16 months). Union was achieved in all patients after the index surgery without postoperative wound complications while one patient came up with checkrein deformity. Average time to radiographic union was 16 weeks (range, 12-24 weeks). All patients had correction to neutral alignment in both coronal and sagittal planes. The average AOFAS ankle-hindfoot score was 90 (range, 77-100) at the last follow-up of patients. CONCLUSIONS: Using a contralateral anterior L-shaped locking compression plate fixation through a posterior-lateral approach with Iliac crest bone graft to reconstruct the distal tibial nonunion is a safe and reliable method that can successfully treat patients with poor soft tissue condition of anterior portion of leg because of its adequate exposure, both tibia and fibula rigid fixation and plenty of bone graft. We believe the application of this method resulting in a high union and low complication rate.

[Endobutton and cortical screw fixation for the treatment of distal tibiofibular syndesmosis separated].

OBJECTIVE: To analyze the treatment effect of Endobutton plate cable system for the treatment of the distal tibiofibular syndesmosis injury. METHODS: Total 38 patients with tibiofibular syndesmosis separation treated by surgical operation from October 2011 to October 2013 were analyzed retrospectively. According to internal fixation, 38 cases were divided into two groups involving group A (cortical screw fixation) and group B (Endobutton plate cable system fixation). In group A, there were 26 patients including 16 males and 10 females with an average age of (37.90±4.67) years old ranging from 19 to 63 years old; 14 cases were on the left and 12 on the right;involving 8 cases of Weber-Denis type B, 18 cases of Weber-Denis type C; according to Lauge-Hanson typing, 9 cases of supination external rotation (SER), 10 cases of pronation abduction (PAB), 7 cases of pronation external rotation (PER). In group B, there were 12 cases including 7 males and 5 females, with an average age of (38.70±6.03) years old ranging from 20 to 55 years old;6 cases were on the left and 6 cases on the right;involving 4 cases of Weber-Denis type B and 8 cases of Weber-Denis; involving 7 cases of PER, 3 cases of SER, 2 cases of PAB. The operative time, intraoperative blood loss, surgery cost, hospital stay time, the wound healing, pain score at 1 month after operation, and the load time were recorded and evaluated. According to reviewing of X rays regulary, the healing of fracture were assessed, the function outcomes of ankle was evaluated according to the Ankle Hind Foot Scale of American Orthopaedic Foot and Ankle Society. RESULTS: All patients were followed up for 8 to 18 months with an average of 13.5 months. There were no statistical significance in intraoperative blood loss, hospital stay time, average load time and postoperative pain score at 1 month after operation between two groups (P>0.05). Duration of operation, the operative time were significantly shorter in cortical screw group;however, the average cost of hospitalization was significantly higher in Endobutton group. No significant differences were found between two groups in outcome of radiographic measurement. The X rays of 36 patients showed well healing of fracture, normal mortise and no distal tibiofibular syndesmosis separation. AOFAS score at the final follow up in group A was (87.50±8.67) scores, 18 cases got excellent result, 4 cases were good, and 4 cases were fair. AOFAS score at the final follow up in group B was (86.23±7.42) scores, 7 cases obtained excellent result, 4 cases were good and 1 case was fair; AOFAS score between two groups were no significant difference (P>0.05). CONCLUSIONS: Endobutton plate cable system is a dynamic capital equipment in treating the tibiofibular syndesmosis separation, it has a similar outcome compared with the screw, but without screw fractured and do not regular remove after operation. The patients could take the functional exercises earlier.

[Comparison of different diameter hollow screw for the treatment of femoral neck fractures].

OBJECTIVE: To evaluate and compare the outcome of two kinds of diameter hollow screws for the treatment of femoral neck fractures. METHODS: From June 2008 to June 2013, 117 patients with femoral neck fractures were treated by closed reduction and hollow screws fixation. Among them,48 patients were fixed by 6.5 mm screw including 30 males and 18 females with an average age of (45.61 ± 11.99) years old ranging from 19 to 60 years old, involving 17 cases in Garden I/II and 31 cases in Garden III/IV; 69 patients were fixed by 8.0 mm screw including 40 males and 29 females with an average age of (45.17 ± 9.95) years old ranging from 18 to 60 years old, involving 31 cases in Garden I/II and 38 cases in Garden III/IV. The general information, operative time, hospital stay time, reduction quality, diameter of femoral head and neck, fracture healing time, the rate of fracture healing, postoperative complications were recorded and evaluated. Harris scoring was used to evaluate the hip joint function. RESULTS: All patients were followed up for 19.6 months (18 to 24 months). The difference of operative time, duration of hospitalization, quality of reduction were not statistically significant (P > 0.05). There was no difference between two groups about the average diameter of the femoral head and neck, the fracture healing time, the rate of healing and the postoperative complications (P > 0.05). There were no difference between two groups about Harris scale. There were significant difference between Garden III/IV and I /II (P > 0.05). CONCLUSION: Closed reduction and internal fixation with hollow screw in treating the young adult patients with femoral neck fracture is the first choice, both different diameters hollow screws could meet the requirements of fixation of femoral neck fracture, and not affect on fracture healing time and postoperative complications.