Partial substitution of chemical fertilizer by Trichoderma biofertilizer improved nitrogen use efficiency in wolfberry (Lycium chinense) in coastal saline land.

A two-year field trial was conducted to investigate the effects of partial substitution of chemical fertilizer (CF) by Trichoderma biofertilizer (TF) on nitrogen (N) use efficiency and associated mechanisms in wolfberry (Lycium chinense) in coastal saline land. As with plant biomass and fruit yield, apparent N use efficiency and plant N accumulation were also higher with TF plus 75% CF than 100% CF, indicating that TF substitution promoted plant growth and N uptake. As a reason, TF substitution stabilized soil N supply by mitigating steep deceases in soil NH4 +-N and NO3 -N concentrations in the second half of growing seasons. TF substitution also increased carbon (C) fixation according to higher photosynthetic rate (Pn) and stable 13C abundance with TF plus 75% CF than 100% CF. Importantly, leaf N accumulation significantly and positively related with Pn, biomass, and fruit yield, and structural equation modeling also confirmed the importance of the causal relation of N accumulation coupled with C fixation for biomass and yield formation. Consequently, physiological and agronomical N use efficiencies were significantly higher with TF plus 75% CF than 100% CF. Overall, partial substitution of CF by TF improved N use efficiency in wolfberry in coastal saline land by stabilizing soil N supply and coupling N accumulation with C fixation.

Growth and DNA Methylation Alteration in Rice (Oryza sativa L.) in Response to Ozone Stress.

With the development of urban industrialization, the increasing ozone concentration (O3) at ground level stresses on the survival of plants. Plants have to adapt to ozone stress. DNA methylation is crucial for a rapid response to abiotic stress in plants. Little information is known regarding the epigenetic response of DNA methylation of plants to O3 stress. This study is designed to explore the epigenetic mechanism and identify a possible core modification of DNA methylation or genes in the plant, in response to O3 stress. We investigated the agronomic traits and genome-wide DNA methylation variations of the Japonica rice cultivar Nipponbare in response to O3 stress at three high concentrations (80, 160, and 200 nmol·mol-1), simulated using open-top chambers (OTC). The flag leaf length, panicle length, and hundred-grain weight of rice showed beneficial effects at 80 nmol·mol-1 O3 and an inhibitory effect at both 160 and 200 nmol·mol-1 O3. The methylation-sensitive amplified polymorphism results showed that the O3-induced genome-wide methylation alterations account for 14.72-15.18% at three different concentrations. Our results demonstrated that methylation and demethylation alteration sites were activated throughout the O3 stress, mainly at CNG sites. By recovering and sequencing bands with methylation alteration, ten stress-related differentially amplified sequences, widely present on different chromosomes, were obtained. Our findings show that DNA methylation may be an active and rapid epigenetic response to ozone stress. These results can provide us with a theoretical basis and a reference to look for more hereditary information about the molecular mechanism of plant resistance to O3 pollution.

Microbial fertilizer regulates C:N:P stoichiometry and alleviates phosphorus limitation in flue-cured tobacco planting soil.

Fertilization can be optimized and managed during the flue-cured tobacco growing period by studying the response of soil and microbial biomass stoichiometric characteristics to fertilization. In this study, we investigated the effect of compound fertilizers combined with microbial fertilizer treatments on the stoichiometric characteristics of the rhizosphere soil and the limitations of microbial resources during the flue-cured tobacco growing period. The results indicated that soil and microbial C:N:P varied greatly with the growing period. The effect of sampling time was usually greater than that of fertilization treatment, and microbial C:N:P did not vary with the soil resource stoichiometric ratio. The microbial metabolism of the tobacco-growing soil was limited by phosphorus after extending the growing period, and phosphorus limitation gradually increased from the root extension to the maturation periods but decreased at harvest. The rhizosphere soil microbial nitrogen and phosphorus limitations were mainly affected by soil water content, soil pH, microbial biomass carbon, and the ratio of microbial biomass carbon to microbial biomass phosphorus. Applying microbial fertilizer reduced phosphorus limitation. Therefore, applying microbial fertilizer regulated the limitation of microbial resources by affecting the soil and microbial biomass C:N:P in flue-cured tobacco rhizosphere soils.

Exogenous hydrogen sulfide and methylglyoxal alleviate cadmium-induced oxidative stress in Salix matsudana Koidz by regulating glutathione metabolism.

BACKGROUND: Cadmium (Cd) is a highly toxic element for plant growth. In plants, hydrogen sulfide (H2S) and methylglyoxal (MG) have emerged as vital signaling molecules that regulate plant growth processes under Cd stress. However, the effects of sodium hydrosulfide (NaHS, a donor of H2S) and MG on Cd uptake, physiological responses, and gene expression patterns of Salix to Cd toxicity have been poorly understood. Here, Salix matsudana Koidz. seedlings were planted in plastic pot with applications of MG (108 mg kg- 1) and NaHS (50 mg kg- 1) under Cd (150 mg kg- 1) stress. RESULTS: Cd treatment significantly increased the reactive oxygen species (ROS) levels and malondialdehyde (MDA) content, but decreased the growth parameters in S. matsudana. However, NaHS and MG supplementation significantly decreased Cd concentration, ROS levels, and MDA content, and finally enhanced the growth parameters. Cd stress accelerated the activities of antioxidative enzymes and the relative expression levels of stress-related genes, which were further improved by NaHS and MG supplementation. However, the activities of monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) were sharply decreased under Cd stress. Conversely, NaHS and MG applications restored the MDHAR and DHAR activities compared with Cd-treated seedlings. Furthermore, Cd stress decreased the ratios of GSH/GSSG and AsA/DHA but considerably increased the H2S and MG levels and glyoxalase I-II system in S. matsudana, while the applications of MG and NaHS restored the redox status of AsA and GSH and further improved glyoxalase II activity. In addition, compared with AsA, GSH showed a more sensitive response to exogenous applications of MG and NaHS and plays more important role in the detoxification of Cd. CONCLUSIONS: The present study illustrated the crucial roles of H2S and MG in reducing ROS-mediated oxidative damage to S. matsudana and revealed the vital role of GSH metabolism in regulating Cd-induced stress.

[Effects of Trichoderma on nitrogen absorption and use efficiency in Lycium chinense roots under saline stress]. / æœ¨éœ‰å¯¹ç›æ¸é€†å¢ƒä¸‹æž¸æžæ ¹ç³»æ°®ç´ å¸æ”¶å’Œæ°®ç´ åˆ©ç”¨æ•ˆçŽ‡çš„å½±å“.

To clarify the mechanisms underlying the improvement of Trichoderma on Chinese wolfberry (Lycium chinense) growth under saline stress, we analyzed the effects of application of organic fertilizer, Trichoderma agent and fertilizer on nitrogen uptake, assimilation, accumulation and use efficiency in Chinese wolfberry, based on a pot experiment with coastal saline soil. The organic fertilizer was the sterilization substance of Trichoderma fertilizer without viable Trichoderma, without any difference in the content of nutrients (such as nitrogen, phosphorus and potassium) between them. The results showed that the application of organic fertilizer, Trichoderma agent and ferti-lizer significantly increased NO3- and NH4+ influx rate in meristematic zone and NO3- influx rate in maturation zone of roots. The magnitude of such enhancement was greater in the application with Trichoderma fertilizer than organic fertilizer. Compared with the control, the application of Trichoderma agent and fertilizer significantly increased root, stem and leaf biomass and nitrogen content as well as plant nitrogen accumulation, strengthened root and leaf nitrate reductase, nitrite reductase and glutamine synthetase activities, and elevated nitrogen uptake efficiency, photosynthetic rate, stable carbon isotope abundance and photosynthetic nitrogen use efficiency. For all those variables, the beneficial effect was obviously stronger in the application with Trichoderma fertilizer than organic fertilizer. Therefore, Trichoderma facilitated nitrogen uptake, assimilation and accumulation in Chinese wolfberry under saline stress, improved photosynthetic carbon fixation ability and nitrogen use efficiency, and ultimately promoted plant growth.

Phytochemical analysis reveals an antioxidant defense response in Lonicera japonica to cadmium-induced oxidative stress.

Cadmium (Cd), though potentially beneficial at lower levels to some plant species, at higher levels is a toxic metal that is detrimental to plant growth and development. Cd is also a carcinogen to humans and other contaminated plant consumers, affecting the kidneys and reducing bone strength. In this study we investigated responses of growth, chlorophyll content, reactive oxygen species levels, and antioxidant responses to Cd in honeysuckle leaves (Lonicera japonica Thunb.), a potential Cd hyperaccumulator. Results indicated that plant height, dry weight, leaf area, and chlorophyll content increased when honeysuckle was exposed to 10 mg kg-1 or 30 mg kg-1 Cd (low concentration). However, in response to 150 mg kg-1 or 200 mg kg-1 Cd (high concentration) these growth parameters and chlorophyll content significantly decreased relative to untreated control plant groups. Higher levels of superoxide radical (O2·-) and hydrogen peroxide (H2O2) were observed in high concentration Cd groups. The activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase were enhanced with exposure to increasing levels of Cd. Additionally, the Ascorbate-Glutathione (AsA-GSH) cycle was activated for the removal of H2O2 in honeysuckle in response to elevated Cd. The Pearson correlation analysis, a redundancy analysis, and a permutation test indicated that proline and APX were dominant antioxidants for removing O2·- and H2O2. The antioxidants GSH and non-protein thiols (NPTs) also increased as the concentration of Cd increased.

Investigation of the chemical structure of anti-amyloidogenic constituents extracted from Thamnolia vermicularis.

ETHNOPHARMACOLOGICAL RELEVANCE: Thamnolia vermicularis (Sw.) Schaer (T. vermicularis) is known to have therapeutic effects on various diseases in Southwest China. Recent research has highlighted that T. vermicularis may suppress Aß level and Tau hyperphosphorylation to improve the pathological characteristics of Alzheimer's disease, indicating that it might have the potential to treat Alzheimer's disease. AIM OF THE STUDY: The objective of this study was to evaluate the inhibitory effect of T. vermicularis on the fibril formation of a typical amyloidogenic protein, hen egg white lysozyme (HEWL), and to identify the effective components that could potentially enable an extract of T. vermicularis to be used in the development of novel therapeutic agents. MATERIALS AND METHODS: A water extract was prepared from T. vermicularis (TVWE) and its inhibitory effect on amyloid fibrillation in vitro was investigated using thioflavin T and 8-anilinonapthalene-1-sulfonic acid spectrofluorometric analyses. The anti-amyloidogenic components of TVWE were separated and qualitatively analyzed using thin layer chromatography (TLC), supercritical carbon dioxide extraction (SFE-CO2), and liquid chromatography-mass spectrometry. Finally, the effect of the bioactive components on the structure of HEWL in the early stages of fibrillogenesis was determined by molecular docking simulation. RESULTS: TVWE strongly inhibited the ability of HEWL to form an amyloid fibril, yielding an IC50 of 0.018 mg/mL for the inhibition of fibrillogenesis. The chemical constituents in the various TVWE fractions resolved by TLC were qualitatively identified by liquid chromatography-quadrupole/time-of-flight mass spectrometry (LC-Q-TOF-MS). The target components were predicted by reviewing the existing literature on T. vermicularis, in which the components of T. vermicularis, along with three small molecules (molecular weight: 182) were preliminarily identified. Molecular docking simulation showed that these small molecules were bound to the core region of HEWL, affecting its stability. Finally, the active anti-amyloidogenic components were extracted from whole T. vermicularis using SFE-CO2 and then identified. CONCLUSION: The potential components of TVWE that could prevent HEWL fibrillogenesis were primarily identified using TLC, LC-Q-TOF-MS, and SFE-CO2. The candidate small-molecule compounds were further predicted by combining the LC-Q-TOF-MS results with molecular docking analysis. The effective components of T. vermicularis were extracted using SFE-CO2. Together, these methods could constitute a practical strategy for the isolation and identification of anti-amyloidogenic components from a traditional Chinese medicine.

Contrasting effects of egg size and appearance on egg recognition and rejection response by Oriental reed warblers.

BACKGROUND: Among potential hosts, the rejection of foreign eggs, which is a common and effective strategy to counter brood parasitism, depends on egg recognition. Multimodal and multicomponent recognition cues of brood parasitic eggs, which include both tactile (size, shape, and texture) and visual (size, shape, color, and maculation) cues, are potentially involved in the perception and discrimination of foreign eggs by hosts. An egg rejection experiment on the host with different types of model eggs can help to accurately assess the relative contribution of different components on egg recognition and constraints to rejection, in which videos can help identify the method of host rejection. METHODS: Here, we assessed egg recognition and rejection responses by Oriental reed warblers (Acrocephalus orientalis), one of the most common hosts of common cuckoos (Cuculus canorus) which breed in eastern China. We designed six groups of model eggs for rejection experiments in which sensory cues included three grades of size and two categories of visual mimicry. RESULTS: Our experiments confirmed that the multimodal traits, which included variation in size, were significant predictors of egg rejection: We detected significantly higher rejection rates of mimetic spotted model eggs than of nonmimetic blue eggs. However, large model eggs did not yield higher rejection rates and, instead, these were less likely to be rejected and more likely to be deserted compared with smaller eggs. Further video-recording data showed that there was no significant effect of egg size on the egg recognition rate (percentage of nests with evidence of egg pecking). No evidence that the egg appearance had an effect on the method of egg rejection (ejection or nest desertion) was found. CONCLUSIONS: Only visual signals, such as color and maculation, contributed to the recognition of foreign eggs by Oriental reed warblers as recognizable clues, but not the egg size. The egg size had an impact on the type of egg rejection. It was less feasible for the warblers to eject large eggs and that is why they opted more often for desertion as the mean of model egg rejection. The significantly lower egg rejection rate of large eggs suggested that although some of them were recognized as foreign eggs, hosts failed to reject these eggs and finally the eggs were assumed to being accepted by the commonly used nest-checking methods.

MB-FSGAN: Joint segmentation and quantification of kidney tumor on CT by the multi-branch feature sharing generative adversarial network.

The segmentation of the kidney tumor and the quantification of its tumor indices (i.e., the center point coordinates, diameter, circumference, and cross-sectional area of the tumor) are important steps in tumor therapy. These quantifies the tumor morphometrical details to monitor disease progression and accurately compare decisions regarding the kidney tumor treatment. However, manual segmentation and quantification is a challenging and time-consuming process in practice and exhibit a high degree of variability within and between operators. In this paper, MB-FSGAN (multi-branch feature sharing generative adversarial network) is proposed for simultaneous segmentation and quantification of kidney tumor on CT. MB-FSGAN consists of multi-scale feature extractor (MSFE), locator of the area of interest (LROI), and feature sharing generative adversarial network (FSGAN). MSFE makes strong semantic information on different scale feature maps, which is particularly effective in detecting small tumor targets. The LROI extracts the region of interest of the tumor, greatly reducing the time complexity of the network. FSGAN correctly segments and quantifies kidney tumors through joint learning and adversarial learning, which effectively exploited the commonalities and differences between the two related tasks. Experiments are performed on CT of 113 kidney tumor patients. For segmentation, MB-FSGAN achieves a pixel accuracy of 95.7%. For the quantification of five tumor indices, the R2 coefficient of tumor circumference is 0.9465. The results show that the network has reliable performance and shows its effectiveness and potential as a clinical tool.

Multi-phase level set algorithm based on fully convolutional networks (FCN-MLS) for retinal layer segmentation in SD-OCT images with central serous chorioretinopathy (CSC).

As a function of the spatial position of the optical coherence tomography (OCT) image, retinal layer thickness is an important diagnostic indicator for many retinal diseases. Reliable segmentation of the retinal layer is necessary for extracting useful clinical information. However, manual segmentation of these layers is time-consuming and prone to bias. Furthermore, due to speckle noise, low image contrast, retinal detachment, and also irregular morphological features make the automatic segmentation task challenging. To alleviate these challenges, in this paper, we propose a new coarse-fine framework combining the full convolutional network (FCN) with a multiphase level set (named FCN-MLS) for automatic segmentation of nine boundaries in retinal spectral OCT images. In the coarse stage, FCN is used to learn the characteristics of specific retinal layer boundaries and achieve classification of four retinal layers. The boundaries are then extracted and the remaining boundaries are initialized based on a priori information about the thickness of the retinal layer. In order to prevent the overlapping of the segmentation interfaces, a regional restriction technique is used in the multi-phase level to evolve the boundaries to achieve fine nine retinal layers segmentation. Experimental results on 1280 B-scans show that the proposed method can segment nine retinal boundaries accurately. Compared with the manual delineation, the overall mean absolute boundary location difference and the overall mean absolute thickness difference were 5.88 ± 2.38µm and 5.81 ± 2.19µm, which showed a good consistency with manual segmentation by the physicians. Our experimental results also outperform state-of-the-art methods.

[Analysis of genomic DNA methylation level in foxtail millet by Methylation Sensitive Amplified Polymorphism].

DNA methylation is an important type of epigenetic modification in eukaryotes. In order to research genome-wide methylation levels and patterns in foxtail millet (Setaria italica), the Methylation Sensitive Amplified Polymorphism (MSAP) analysis (employing double digestion with EcoR I and Hpa II/Msp I) was established and applied in two foxtail millet cultivars (Chaogu 58 and Yugu 1). The results showed that 32 pairs of MSAP primers were selected from 100 MSAP primers, and 1 615 and 1 482 clearly distinguishable and reproducible bands were amplified from Chaogu 58 and Yugu 1 respectively, including 3 types of methylation patterns. Cytosine methylation levels of CCGG context in Chaogu 58 and Yugu 1 were characterized as 6.93% and 8.77% respectively. Such different genomic DNA methylation levels between two foxtail millet varieties may provide a preliminary reference for the cultivation of this crop from a novel epigenetic viewpoint.

[Comparison of MITE transposons mPing in different rice subspecies].

The mPing family is the first active MITE TE family identified in rice genome. In order to compare the compositions and distributions of mPing family in the genomes of two rice subspecies japonica (cv. Nipponbare) and indica (cv. 93-11), we initially estimated the copy numbers of mPing family in those two subspecies using Southern blot and then confirmed the results by searching homologous copies in each reference genome using Blastn program, which turned out to have 52 and 14 mPing copies in corresponding reference genome, respectively. All mPing members in Nipponbare genome belong to mPing-1, while there are 3 mPing-1 and 11 mPing-2 copies in 93-11 genome. By further investigating the 5-kb flanking sequences of those mPing copies, it was found that 23 and 3 protein-coding genes in Nipponbare and 93-11 genome are residing adjacent to those mPing copies respectively. These results establish the preliminary theoretical foundation for further dissecting the genetic differences of japonica and indica rice in terms of the diversities and distributions of their component mPing.

[Effects of elevated ozone on Pinus armandii growth: a simulation study with open-top chamber].

By using open-top chamber (OTC) and the techniques of dendrochronology, this paper studied the growth of Pinus armandii under elevated ozone, and explored the evolution dynamics and adaptation mechanisms of typical forest ecosystems to ozone enrichment. Elevated ozone inhibited the stem growth of P. armandii significantly, with the annual growth of the stem length and diameter reduced by 35.0% and 12.9%, respectively. The annual growth of tree-ring width and the annual ring cells number decreased by 11.5% and 54.1%, respectively, but no significant change was observed in the diameter of tracheid. At regional scale, the fluctuation of ozone concentration showed significant correlation with the variation of local vegetation growth (NDVI).

[Effects of elevated O3 concentration on anti-oxidative enzyme activities in Pinus tabulaeformis].

An open-top chamber experiment was conducted to study the effects of high concentration O3 (80 nmol x mol(-1)) on the superoxide anion radical (O2*-) generation rate, hydrogen peroxide (H2O2) content, activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and glutathione reductase (GR), and ascorbic acid content in Pinus tabulaeformis leaves. Under high concentration O3 exposure, the superoxide anion radical generation rate and H2O2 and malondialdehyde (MDA) contents increased, while the ascorbic acid content and the activities of SOD, APX, DHAR, MDHAR, and GR increased in early growth season but decreased then to a level lower than the control, which illustrated that the antioxidant system of P. tabulaeformis did respond in an acclimation way in the early growth season, but could not bear the damage of long-term elevated O3 exposure.

Changes of main secondary metabolites in leaves of Ginkgo biloba in response to ozone fumigation.

To investigate the effect of elevated O3 on the accumulation of main secondary metabolites in leaves of Ginkgo biloba L., four-year-old trees were exposed in open-top chambers with ambient air and the air with twice ambient O3 concentration in Shenyang in 2006. Elevated O3 increased the concentrations of terpenes, but decreased the concentrations of phenolics in G. biloba leaves. The results showed that secondary compounds from G. biloba leaves responded to the elevated O3 exposure in a different way when compared to previous studies which showed elevated O3 increased the concentrations of phenolics but had no effect on the terpenes in leaves of other deciduous trees. Furthermore, reduced synthesis of phenolics may decrease the resistance of G. biloba to O3 and other environmental factors. On the other hand, the induced synthesis of terpenes may enhance the antioxidant abilities in G. biloba leaves at the end of O3 fumigation.

Influence of elevated carbon dioxide and ozone on the foliar nonvolatile terpenoids in ginkgo biloba.

The aim of this study was to determine the effects of elevated O(3) and elevated CO(2,) singly and in combination, on the contents of nonvolatile terpenoids in leaves of Ginkgo Biloba. The results showed that elevated CO(2), alone and in combination with elevated O(3) increased concentrations of all the determined terpenoids, while elevated O(3) alone only increased concentration of bilobalide. These results demonstrated that the metabolism of terpenoids in ginkgo leaves was more sensitive to elevated CO(2) than elevated O(3).