Fruit Photosynthesis and Assimilate Translocation and Partitioning: Their Characteristics and Role in Sugar Accumulation in Developing Citrus unshiu Fruit

Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in developing satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa wase) fruit from primary stage of fruit enlargement up to fruit full ripe. Change in fruit photosynthetic rate was some what related to the change in the chlorophyll content of peel. Fruit photosynthetic rate markedly declined as chlorophyll degradation occurred in the peel. Before full ripe stage of the fruit, photosynthates produced by a 14C-fed leaf were mainly distributed to juice sacs even during periods when dry matter accumulation in peel was more rapid than that in juice sacs. At the full ripe stage, peel photosynthetic rate approached zero and peel became the major sink of leaf photosynthates. Most of the peel assimilates, however, remained in situ for up to 48 h after feeding 14CO 2 to the fruit, only a small portion being transported to other parts of fruit. The percentage of fruit photosynthates exported decreased with fruit development and ripening, but the peak rate of export to juice sacs amount to as high as 12%. The sugar content and dry weights of peel and juice sacs in shaded fruit were lower than that in the control fruit. These results show that peel assimilate was mainly consumed in peel respiration and growth and thus the dependence on leaf photosynthates decreased. Part of this assimiate was used in sugar accumulation in juice sacs of fruit.

Interspecific Transition Among Caragana microphylla, C. davazamcii and C. korshinskii Along Geographic Gradient. Ⅱ. Characteristics of Photosynthesis and Water Metabolism

The characteristics of photosynthesis and water metabolism of Caragana microphylla Lam.,C. davazamcii Sancz. and C. korshinskii Kom. populations in different sites (117.6o-105.7o E, 44.6o-38.8o N)were studied. (1) From the east to the west, the responses of the three species to photosyntheticallyavailable radiation (PAR) in net photosynthesis rate increased, the relative humidity of the air whichcorresponded to the occurrence of maximum photosynthesis rate decreased, and the corresponding airtemperature increased. Along the same gradient, the before-noon superiority of the photosynthesis be-came evident, and the photosynthesis rate and the light use efficiency (LUE ) increased, while the transp-iration rate decreased, thus the water use efficiency (WUE ) increased notably, and the leaf water contentdecreased gradually. From the east to the west, the plants took a water-saving strategy step by step withhigher photosynthesis rate and lower transpiration rate. These physiological changes in the plants wereadaptable to the conditions of light, temperature and humidity in the habitat of the plants, and might be thebiological foundation for the geographical transition among C. microphylla , C. davazamcii and C. korshinskii.(2) The adaptation of photosynthetic system of C. microphylla , C. davazamcii and C. korshinskii to PAR, airhumidity and temperature exhibited the interspecific continuity, which was consistent with theenvironmental gradient. In different species and different sites, the diurnal changes of net photosynthesisrate, the daily cumulative value of net photosynthesis, the diurnal changes of transpiration rate, the dailycumulative value of transpiration, the water use efficiency and the diurnal changes of leaf water contentvaried with longitudinal descent (from the east to the west). The characteristics of photosynthesis andwater metabolism indicated that the geographical transition among C. microphylla , C. davazamcii and C.korshinskii was in gradual change, and these three species formed a geographical cline.

Effects of Water Stress on Photosynthesis and Fluorescence Characteristics in Peony

[ Objective] Study on the photosynthesis and fluorescence characteristics in peony under water stress. [ Method ] The two peony varieties Huhong and Luoyanghong were treated by different water stress for determining the photosynthesis and fluorescence characteristics. [ Result ] With the aggravation of water stress, the net photosynthetic rate （Pn） and stomatal conductance （Gs） decreased, while the intercellular CO2 concentration （Ci） increased. Drought could decrease Pn, constrain gas exchange and change the daily photosynthesis. Fo of peony leaf increased and Fv/Fm decreased under water stress especially water logging, causing the inactivation of the PS II reaction center, and the chlorophyll fluorescence characters gradually recovered until afternoon. [ Conclusion] The 75% soil relative water content （SRWC） is the best condition for growth of peony. Compared with drought, water logging is more unfit for the growth of peony. For the two varieties, Huhong assumed more tolerance to drought, accordingly more adaptability.

Response of Photosynthesis, Growth, Carbon Isotope Discrimination and Osmotic Tolerance of Rice to Elevated CO_2

Four rice ( Oryza sativa L.) cultivars 'IR72', 'Tesanai 2', 'Guichao 2' and 'IIyou 4480' were grown in two plastic house (15 m×3 m) with 35 μmol/mol and 60 μmol/mol CO 2 concentration which was controlled by computer. As compared with rice at ambient 35 μmol/mol CO 2, the changes in photosynthetic rate at elevated CO 2 showed up_regulation ('IR72' and 'Tesanai 2'), stable (unchanged) in 'Guichao 2' and down_regulation type ('IIyou 4480'). Growth rate, panicle weight, integrated water use efficiency (WUE) calculated from Δ 13 C and the capacity of scavenging DPPH · (1,1_diphenyl_2_picrylhydrazyl) free radical were increased at elevated CO 2. An increment in total biomass was observed in three cultivars by elevated CO 2, with the exception of 'IIyou 4480'. Ratios of panicle weight/total biomass were altered to different extents in tested cultivars by elevated CO 2. When leaf segments were subjected to PEG osmotic stress, the electrolyte leakage rate from leaves grown at elevated CO 2 was less than that at 35 μmol/mol CO 2. Those intraspecific variations of rice imply a possibility for selecting cultivars with maximal productivity and high tolerance to stresses adapted to elevated CO 2 in the future.

Species- and Habitat-variability of Photosynthesis, Transpiration and Water Use Efficiency of Different Plant Species in Maowusu Sand Area

Photosynthesis ( P n ), transpiration ( E ) and water use efficiency ( WUE ) of more than 66 arid sand species from different environmental habitats, shifting sand dune, fixed sand dune, lowland and wetland in the Maowusu Sand Area were analyzed and the relation among these characteristics and the resource utilization efficiency, taxonomic categories and growth forms of the species were assessed. The results showed that species from Chenopodiaceae, Gramineae, Leguminosae which possessed the C 4 photosynthesis pathway, or C 3 pathway and also with nitrogen_fixation capacities had higher or the highest P n values, i.e., 20～30 μmol CO 2·m -2 ·s -1 , while that of evergreen shrub of Pinaceae had the lowest P n values, i.e., 0～5 μmol CO 2·m -2 ·s -1 . Those species from Compositae, Scrophulariaceae, and Gramineae with C 3 pathway but no N_fixation capacity had the highest E rates, i.e., 20～30 mmol H 2O·m -2 ·s -1 and again the evergreen shrub together with some species from Salicaceae and Compositae had the lowest E rates, i.e., 0～5 mmol H 2O·m -2 ·s -1 . Species from Leguminosae, Gramineae and Chenopodiaceae with C 4 pathway or C 3 pathway with N_fixation capacity, both shrubs and grasses, generally had higher WUE . However, even the physiological traits of the same species were habitat_ and season_specific. The values of both P n and E in late summer were much higher than those in early summer, with average increases of 26%, 40% respectively in the four habitats. WUE in late summer was, however, 12% lower. Generally, when the environments became drier as a result of habitats changed, i.e., in the order of wetland, lowland, fixed sand dune and shifting sand dune, P n and E decreased but WUE increased.

Fluorescence Study on The Interaction Between Cisplatinand Erythrocyte Membrane Proteins

The interaction between cisplatin and erythrocyte membrane proteins was studied based on the quenching effect of cisplatin on the intrinsic fluorescence of proteins.A concentration-dependent quenching effect was observed.The presence of chloride and sulphate weakens the effect significantly.A pH-dependence was also noted with a stronger effect in acidic solution. The nature of the interaction is considered to be platinum-thiol group binding according to the effect of cisplatin on the fluorescence of FMA labeled membrane. The mechanism of the cisplatin-protein interactions was discussed based on the effect of coexisting anion

Effect of Silicon on Leaf Ultrastructure, Chlorophyll Content and Photosynthetic Activity of Barley Under Salt Stress

Two contrasting cultivars of barley (Horderm vykgare L.): Kepin No. 7 (salt sensitive), and Jian 4 (salt tolerant) were grown in a hydroponics system with 2 NaCl levels: 60 mmol NaCl L-1 and 120 mmol NaCl L-1, and 3 Si levels: 0 mmol Si L-1, 0.5 mmol Si L-1 and 1.0 mmol Si L-1 (as silicic acid). Compared with the plants treated with 60 mmol NaCl L-1 alone, the leaf chlorophyll contents of plants treated with salt and Si increased significantly for salt-sensitive cultivar at tillering stage, but for salt-tolerant cultivar,the addition of Si resulted in an obvious increase in the leaf chlorophyll content of plants exposed to 120 mmol NaCl L-1. However, this Si-enhancement of leaf chlorophyll content was also observed in the salttolerant plants at jointing stage, but not in the salt-sensitive plants. Moreover, leaf chlorophyll content was consistently higher for the salt-tolerant cultivar than for the salt-sensitive cultivar irrespective of salt and/or Si treatment. Compared with the plants treated with salt alone, net CO2 assimilation rate in plant leaves increased significantly for both cultivars when trested with salt and Si. The addition of Si to the salt treatment was found to improve the cell ultrastructure of leaves. Under salt stress condition, the double membranes of chloroplasts disappeared, but membrane integrity was markedly improved in the salt treatment supplemented with Si. Silicon was also found to ameliorate the damage to the ultrastructure of chloroplast granae which appeared to be disintegrated and vague in salt treatments without added Si. The results support previous work which showed that Si decreases the permeability of plasma membranes of salt-stressed barley, thus mitigating salt damage.

Vegetation/Soil Synthesis Water Index Using MODIS Data

In consideration of the spectral character of MODIS (Moderate Resolution Imaging Spectroradiometer) dataand the reflective spectrum of vegetation and soil, NDVI (Normalized Difference Vegetation Index) and NDWI (Nor-malized Difference Water Index) are deduced using one visible band (0.66μm) and two near-infrared bands (0.86μm,1.24 μm). Vegetation canopy temperature is derived using two thermal infrared bands (8.6 μm and 11μm). Then thevegetation/soil synthesis water index (VSWI) is acquired through analyzing the coupling character of three indexeswhich can reflect the water condition of vegetation. Finally, the synthesis index is verified by equivalent water contentof a single leaf. The matching results show that the synthesis index is directly proportional to the modeled data,which means that the vegetation water content can be reflected using the synthesis index effectively.

A Kinetic Spectrophotometric Method for the Determination of Iron (Ⅲ) in Water Samples

A new kinetic spectrophotometric method has been developed for the determination of iron （Ⅲ）. The method is based on the catalytic effect of iron （Ⅲ） on the oxidation of weak acid brilliant blue dye （RAWL） by KIO4 in acid medium. The advantages of the proposed method are that it is sensitive, accurate, rapid, inexpensive, can be operated under room temperature and has a large determination concentration range compared to other techniques. The obtained optimum conditions are： pH 3.15, RAWL （200 mgL^-1） 5.00mL, Potassium periodate solution （0.01 molL^-1） 0.30mL, phenanthroline （0.02 molL^-1） 1.00mL, reaction temperature 25℃ and reaction time 7 min. With this method iron could quantitively be determined in the range 0.00-0.02 mgL^-1, the detection limit being 4.10 × 10^10gmL^-1. The relative standard deviations （RSD） in five replicate determinations for 3 μgL^-1and 5 μgL^-1 iron （Ⅲ） are 3.1% and 1.9%, respectively. The method has been applied to the determination of iron （Ⅲ） in tap water samples and seawater samples （from the South China Sea）, the recovery rates being 98.0% and 100.5%, respectively.

Autocrine expression of hepatocyte growth factor and its cytoprotective effect on hepatocyte poisoning

AIM: To construct pEGFP-hepatocyte growth factor (HGF) expression vector, the to detect its expression in transfected human hepatocytes, and to investigate the influence of autocrine HGF expression on the proliferative potential and cytoprotective effects in human hepatocytes.METHODS: Human HGF cDNA was ligated to the pEGFP vector. Recombinant plasmid was transfected into human hepatocyte line QZG with liposome. Expression of HGF protein was observed by fluorescence microscopy and immunohistochemistry. Hepatic cells were collected 24, 48, and 72 h after transfection to detect the number of [^3H]-TdR uptake in DNA. DNA synthesis was observed by using PCNA stain immunohistochemistry.Acute liver cell damage was induced by carbon tetrachloride. Cytoprotective effect was observed by examining the survival rate of hepatocytes and leakage of intracellular alanine transaminase (ALT) and potassium ions.RESULTS: HGF identification of pEGFP-HGF by enzyme digestion showed that HGF fragment was cloned into BamH I and SalI sites of pEGFP-N3. Expression of GFP in transfected hepatocytes was observed with fluorescence microscopy. The [^3H]-TdR uptake became 7 times as many as in thecontrol group 96 h after transfection. After HGF transfection, the survival rate of hepatocytes poisoned by CCI4 significantly increased (83% vs 61%, P<0.05), and the leakage of intracellular alanine transaminase and potassium ions decreased (586 nkat/L vs 1089 nkat/L, P<0.01; and 5.59 mmol/L vs 6.02 mmol/L, P<0.01 respectively). Culture of transfected hepatic cells promoted the proliferation of other nontransfected cells.CONCLUSION: Transfected HGF is expressed in hepatic cells and has the activity of promoting cell division and protecting hepatic cells against poisoning.

Analysis of expressed sequence tags from the Ulva prolifera (Chlorophyta)

In 2008, a green tide broke out before the sailing competition of the 29th Olympic Games in Qingdao. The causative species was determined to be Enteromorpha prolifera （Ulva prolifera O. F. Miiller）, a familiar green macroalga along the coastline of China. Rapid accumulation of a large biomass of floating U. prolifera prompted research on different aspects of this species. In this study, we constructed a nonnormalized cDNA library from the thalli of U. prolifera and acquired 10072 high-quality expressed sequence tags （ESTs）. These ESTs were assembled into 3 519 nonredundant gene groups, including 1 446 clusters and 2 073 singletons. After annotation with the nr database, a large number of genes were found to be related with chloroplast and ribosomal protein, GO functional classification showed 1 418 ESTs participated in photosynthesis and 1 359 ESTs were responsible for the generation of precursor metabolites and energy. In addition, rather comprehensive carbon fixation pathways were found in U. prolifera using KEGG. Some stress-related and signal transduction-related genes were also found in this study. All the evidences displayed that U. prolifera had substance and energy foundation for the intense photosynthesis and the rapid proliferation. Phylogenetic analysis of cytochrome c oxidase subunit I revealed that this green-tide causative species is most closely affiliated to Pseudendoclonium akinetum （Ulvophyceae）.

Corona Discharge Ion Mobility Spectrometry of Ten Alcohols

Ion mobility spectra for ten alcohols have been studied in an ion mobility spectrometry apparatus equipped with a corona discharge ionization source. Using protonated water cluster ions as the reactant ions and clean air as the drift gas, the alcohols exhibit different product ion characteristic peaks in their ion mobility spectra. The detection limit for these alcohols is at low concentration pmol/L level according to the concentration calibration by exponential dilution method. Based on the measured ion mobilities, several chemical physics parameters of the ion-molecular interaction at atmosphere were obtained, including the ionic collision cross sections, diffusion coefficients, collision rate constants, and the ionic radii under the hard-sphere model approximation.

Cotton Physiological Parameters Affected by Episodic Irrigation Interruption

Improving cotton irrigation management practices in West Texas is important for increasing farmers＇ profits and for sustainability of the Ogallala aquifer. The objective of this work was to evaluate the effects in field controlled episodic drought conditions on cotton gas exchange. Irrigated cotton was subjected to water stress at different timings. Irrigation was interrupted at the squaring stage, early flowering stage, from three weeks at peak bloom, and from peak bloom to the crop termination. These episodic drought treatments were compared with cotton fully irrigated throughout the whole season. From 2010 to 2012, cotton cultivar FM9180 gas exchange was measured throughout the season using a LiCor-6400 portable photosynthesis system. In 2011 and 2012, measurements were also made on DP0935 cultivar. The cotton physiological parameters evaluated included photosynthesis, transpiration and temperature. From the several parameters evaluated, some relationships were presented. Episodic drought periods can affect leaf-level gas exchange and impact yield. Photosynthesis and yield were particularly sensitive to water deficit at early flowering. Despite an increase in leaf water use efficiency under water deficit, overall growth and yield were inhibited in all treatments with a stress component. Understanding the relative sensitivity at different growth stages can help with irrigation decisions when water resources are limited.

Photoelectron Spectroscopy, Photoionization Mass Spectroscopy, and Theoretical Study on CCl3SSCN

Trichloromethanesulfenyl thiocyanate, CCl3SSCN, was generated and studied by photoelectron spectroscopy （PES）, photoionization mass spectroscopy （PIMS）, and theoretical calculations. This molecule exhibits a gauche conformation, and the torsional angle around S-S bond is 91.4° due to the sulfur-sulfur lone pair interactions. After ionization, the ground-state cationic-radical form of CCl3SSCN＋ adopts a trans planar main-atom structure with Cs symmetry. The highest occupied molecular orbital （HOMO） of CC13SSCN corresponds to the electrons mainly localized on the sulfur 3p lone pair MO. The first ionization energy is determined to be 10.40 cV.

A thioether-functionalized pyrene-based covalent organic framework anchoring ultrafine Au nanoparticles for efficient photocatalytic hydrogen generation

Covalent organic frameworks(COFs)have lately emerged as a blooming class of potential materials for photocatalytic water splitting because of their high crystallinity,huge surface areas,and structural versatility.However,the photocatalytic performance for most pure COFs face some limitations factors,such as the significant recombination of photogenerated carriers and slow charge transfer.Herein,a novel thioether-functionalized pyrene-based COF(S_(4)-COF)was effectively produced and chosen as a support for the immobilization of ultrafine gold nanoparticles(Au NPs).S_(4)-COF photocatalyst with Au as cocatalyst demonstrates remarkable photocatalytic activity with a H_(2) generation rate of 1377μmol g^(−1) h^(−1) under visible light(>420 nm),which is ca.4.5-fold increase comparing to that of pure S_(4)-COF(302μmol g^(−1) h^(−1)).Au NPs anchored on S_(4)-COF possess an ultrafine size distribution ranging from 1.75 to 6.25 nm with an average size centered at 3.8 nm,which benefits from the coordination interaction between thioether groups and Au.Meanwhile,the produced Au@S_(4)-COF can generate a stable photocatalytic H_(2) generation during the four recycles and preserve its crystallinity structure after the stability testing.The Au NPs anchored on the S_(4)-COF photocatalyst can greatly accelerate the separation of photogenerated carriers and increase charge transfer because of the combined function of Au NPs and thioether groups.Such a method can not only prevent the aggregation of Au NPs onto thioether-containing COFs to achieve long-term photostability but also allow uniform dispersion for an ordered structure of photocatalysts.This work provides a rational strategy for designing and preparing COF-based photocatalysts for solar-driven H_(2) production.

Manifestation If Substance Molecular Structure in Temperature Effects of Light Scattering

DCMSL （depolarization components of molecular scattering of light） have been studied within the wide spectral range （0-200 cm-1） and in the temperature intervals （20-200 ℃） in toluol （C6HsCH3） and aniline （C6HsNH2）. It has been shown that when a liquid is heated and temperatures approach to critical ones, a significant contribution of DCMSL is made by vibration motion of molecules. The special properties of the temperature-frequency behavior of DCMSL spectra are discussed from the view point of hindered rotation of liquid molecules with consideration of intermolecular interaction.

Vibrational Spectra and Adsorption of Trisiloxane Superspreading Surfactant at Air/Water Interface Studied with Sum Frequency Generation Vibrational Spectroscopy

The C-H stretch vibrational spectra of the trisiloxane superspreading surfactant Silwet L-77 （（CH3）3Si- O-Si（CH3）（C3H6）（OCH2CH2）7-8OCH3）-O-Si（CH3）3） at the air/water interface are measured with the surface Sum Frequency Generation Vibrational Spectroscopy （SFG-VS）. The spectra are dominated with the features from the -Si-CH3 groups around 2905 cm^-1 （symmetric stretch or SS mode） and 2957 ^-1 （mostly the asymmetric stretch or AS mode）, and with the weak but apparent contribution from the -O-CH2- groups around 2880 ^-1 （symmetric stretch or SS mode）. Comparison of the polarization dependent SFG spectra below and above the critical aggregate or micelle concentration （CAC） indicates that the molecular orientation of the C-H related molecular groups remained unchanged at different surface densities of the Silwet L-77 surfactant. The SFG-VS adsorption isotherm suggested that there was no sign of Silwet L-77 bilayer structure formation at the air/water interface. The Gibbs adsorption free energy of the Silwet surfactant to the air/water interface is -42.2±0.8kcal/mol, indicating the unusually strong adsorption ability of the Silwet L-77 superspreading surfactant.

Laser Light Scattering Study on Aggregation of Cellulose Diacetate in Acetone

We have investigated the properties of cellulose diacetate in solution by using laser light scattering. The cellulose diacetate molecules can form micelles and micellar clusters in acetone besides the individual chains. As the concentration increases, the average hydrodynamic radius （Rh） linearly increases, whereas the ratio of gyration radius to hydrodynamic radins 〈Rg〉/〈Rh〉 linearly decreases. It indicates that the micelles associate and form micellar clusters due to the intermolecular interactions.

Effect of Rust Disease on Photosynthetic Rate of Wheat Plant

The purpose of this research was to study the influence of rust diseases on photosynthetic rate of the created local varieties and introduced variety samples of wheat. Experiment was carried out with two variants-control and 25% Tilt treatment. The 25% solution of Tilt was used to prevent disease infection. The photosynthetic rate was measured by T-type URAS-2 infrared gas analyzer （made＇ in Germany）. Disease infection rate was determined based on the Cobby balling scale. Ontogenetic and daily rate of photosynthesis by effect of the disease were decreased. The amount of assimilated CO2 during the day and vegetation period linearly depends on the disease infection degree. At the same time, the activation of non-infected parts＇ photosynthetic rate of some varieties was observed. The difference reaches up to 87% between the variants as a result of the rapid aging of photosynthesis apparatus.