Publications by authors named "XinXiang Xu"

Potassium (K) and magnesium (Mg) play analogous roles in regulating plant photosynthesis and carbon and nitrogen (C-N) metabolism. Based on this consensus, we hypothesize that appropriate Mg supplementation may alleviate growth inhibition under low K stress. We monitored morphological, physiological, and molecular changes in G935 apple plants under different K (0.

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Article Synopsis
  • - The study investigates how nitrogen (N) and potassium (K) interaction affects photosynthesis in apple rootstock M9T337 using hydroponics to analyze different nutrient conditions.
  • - High N with low K leads to a deficiency in K in both roots and leaves, creating an N/K imbalance that negatively impacts leaf photosynthesis through various limitations.
  • - Adjusting N levels under low K conditions can enhance protein distribution and improve the photosynthetic process by increasing key rates, suggesting that balancing N and K is crucial for optimal plant health.
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Cuticular waxes play important roles in plant development and the interaction between plants and their environment. Researches on wax biosynthetic pathways have been reported in several plant species. Also, wax formation is closely related to environmental condition.

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Selenium (Se) can be absorbed by plants, thereby affects plant physiological activity, interferes gene expression, alters metabolite content and influences plant growth. However, the molecular mechanism underlying the plant response to Se remains unclear. In this study, apple plants were exposed to Se at concentrations of 0, 3, 6, 9, 12, 24, and 48 μM.

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Introduction: Both nitrogen (N) and magnesium (Mg) play important roles in biochemical and physiological processes in plants. However, the application of excessive N and insufficient Mg may be the factor leading to low nitrogen utilization rate (NUE) and fruit quality degradation in apple production.

Methods: In this study, we analyzed the effects of different application rates of Mg (0, 50, 100, 150, 200 kg/ha) on the photosynthetic nitrogen use efficiency (PNUE), the accumulation and distribution of carbon (C), N metabolism, anthocyanin biosynthesis and fruit quality of the 'Red Fuji' apple in 2018 and 2019.

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Both magnesium (Mg) and nitrogen (N) play many important roles in plant physiological and biochemical processes. Plants usually exhibit low nitrogen utilization efficiency (NUE) under Mg deficiency conditions, but the mechanisms by which Mg regulates NUE are not well understood. Herein, we investigated biomass, nutrient uptake, sorbitol and sucrose transport, and relative gene expression in apple seedlings under various concentrations of Mg and N treatments in hydroponic cultures.

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Previous studies have determined that magnesium (Mg) in appropriate concentrations prevents plants from suffering from abiotic stress. To better understand the mechanism of Mg alleviation of aluminum (Al) stress in apple, we investigated the effect of Mg on plant growth, photosynthetic fluorescence, antioxidant system, and carbon (C) and nitrogen (N) metabolism of apple seedlings under Al toxicity (1.5 mmol/L) via a hydroponic experiment.

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Nitrogen (N) and potassium (K) have significant effects on apple peel color. To further understand the molecular mechanism of N-K regulation of apple color, we analyzed the apple peel under different N and K treatments using isotope labeling, transcriptomics, and metabolomics. Under high N treatments, fruit red color and anthocyanin content decreased significantly.

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The outbreak of the coronavirus disease (COVID-19) pandemic, a significant health threat, influenced information-related behaviors and induced increased rumor-sharing behaviors on social media. Fighting COVID-19 thus entails the need to fight the rumors as well, providing a strong motivation to explore rumor-related behavior during this extraordinary period. From the perspective of information acquisition, we predicted that information acquisition from social and traditional media would interactively influence rumor-related decisions (i.

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Excessive nitrogen (N) supply often leads to an imbalance of carbon (C) and N metabolism and inhibits plant growth. Sucrose, an important source and signaling substance of C in plants, is closely linked to N metabolism. However, it is not clear whether exogenous sucrose can mitigate the inhibitory effect of high N on plant growth by regulating C and N metabolism.

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Potassium (K) is an indispensable nutrient element in the development of fruit trees in terms of yield and quality. It is unclear how a stable or unstable supply of K affects plant growth. We studied the root morphology and physiological and molecular changes in the carbon and nitrogen metabolism of M9T337 apple rootstock under different K levels and supply methods using hydroponics.

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During the COVID-19 pandemic, online health platforms and physicians' online knowledge sharing played an important role in public health crisis management and disease prevention. What influences physicians' online knowledge sharing? From the psychological perspective of stimulus-response, this study aims to explore how patients' visit and patients' consultation influence physicians' online knowledge sharing considering the contingent roles of physicians' online expertise and online knowledge sharing experience. Based on 6-month panel data of 45,449 physician-month observations from an online health platform in China, the results indicate that both patients' visit and patients' consultation are positive related to physicians' online knowledge sharing.

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In China, excessive application of nitrogen (N) fertilizer is common in intensive apple production. To resolve issues of benefit reduction and environmental pollution caused by excessive N, a two-year trial was conducted in an apple orchard with a split-plot design, in which the main factor was the N level (500, 400, 300, and 200 kg N ha year, expressed as TN, TN80%, TN60%, and TN40%, respectively) and the deputy factor was whether or not to add 3,4-dimethylpyrazole phosphate (DMPP, expressed as +D). The effects of N reduction combined with DMPP on soil N transformation, fruit quality, economic benefits, and environmental effects were investigated.

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Excessive application of nitrogen (N) fertilizer is common in Chinese apple production. High N reduced the contents of soluble sugar and total flavonoids by 16.05 and 19.

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In order to define translocation characteristics of C-photoassimilates to fruit during the fruit development stage in 'Fuji' apple, the C labeled tracer method was used in whole five-year-old 'Fuji'3/M26/Malus hupehensis (Pamp.) Rehder apple trees at different days after flowering (DAF). The changes in C translocation to the fruit, source strength of the leaves, and sink strength of the fruits were assessed.

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Nitrogen (N) is one of the most required mineral elements for plant growth, and potassium (K) plays a vital role in nitrogen metabolism, both elements being widely applied as fertilizers in agricultural production. However, the exact relationship between K and nitrogen use efficiency (NUE) remains unclear. Apple dwarf rootstock seedlings (M9T337) were used to study the impacts of different K levels on plant growth, nitrogen metabolism, and carbon (C) assimilation in water culture experiments for 2 years.

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In order to solve the problems of nitrogen (N) losses and fruit quality degradation caused by excessive N fertilizer application, different dosages of the nitrification inhibitor, 3,4-dimethylpyrazole phosphate (DMPP) (0, 0.5, 1, 2, and 4 mg kg soil), were applied during the later stage of 'Red Fuji' apple ( Borkh.) fruit expansion in 2017 and 2018.

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A field experiment was carried out in a six-year old 'Fuji'3/M26/Malus hupehensis Rehd. apple with the C tracer method to examine the changes of chlorophyll fluorescence parameters, photosynthetic characteristics of leaf, sugar transporter gene expression, C assimilation capability and the characteristics of translocation and distribution of C-photoassimilates to fruit under different levels of potassium addition (KO 0, 0.5%, 1.

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In order to improve the problem of poor coloring caused by high fruit nitrogen in apple production, we studied the effects of different concentrations of abscisic acid (ABA: 0, 50, 100, and 150 mg/L) and fluridone (ABA biosynthesis inhibitor) on the fruit of 'Red Fuji' apple ( Borkh.) in the late stage of apple development (135 days after blooming) in 2017 and 2018. The effects of these treatments on the distribution of C and N and anthocyanin synthesis in fruit were studied.

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To compare the effects between gene therapy and gradual release carrier for bone morphogenetic protein-2 (BMP-2) in repairing bone defects, bone defects for 15 mm were created.on the bilateral radius in rabbits and treated with four kinds of implantations, ie, composite of transgeneic MSCs and PLA/PCL (Group A), composite of MSCs and gradual release carrier for BMP-2 (Group B), composite of MSCs and PLA/PCL (Group C), and PLA/PCL alone (Group D). After 4, 8, and 12 weeks of the operations, X-ray, histological examination, biomechanics analysis, and bone density measurement were conducted.

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Adenovirus carrying BMP-2 gene, after being mixed with fibrinous gel, was siphoned off on biodegradable scaffolds (PLA/PCL). The composite was used to repair 1.5 cm long radius defect in rabbits.

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Objective: To label the primary articular chondrocytes overexpressing human insulin-like growth factor (hIGF 1) with green fluorescent protein (GFP) for repair of articular cartilage defects in rabbits.

Methods: GFP cDNA was inserted into pcDNA3.1 hIGF 1 to label the expression vector.

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Objective: To study the effects of BMP-2 gene therapy on vascularization in repairing bone defects.

Methods: The isolated rabbit mesenchymal stem cells (rBMSC), after being transfected by adenovirus carrying BMP-2 gene (Ad-BMP-2) and seeded on xenogeneic bone scaffolds, were used to repair 1.5 cm-long radius bone defects.

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Seeding is the crucial step in bone tissue engineering. In current study, static and dynamic seeding methods for human bone marrow stem cells (hBMSCs) were compared. The methods for assay of DNA content in the constructs after seeding were adopted.

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