The Effect of Boron on the Properties of Glucomannan: An Experimental and Molecular Dynamics Simulation Study

The effect of boron on the properties of Konjac Glucomanan （KGM） has been investigated by the method of experiment and molecular dynamic simulation. Upon analysis, the property and structure of KGM are apt to be affected by boron and structural reasons for property change were discussed. In detail, the addition low concentration borax can increase the systematic inherent viscosity, by contrast, high concentration borax has opposite effect on the viscosity. When adding borax, the micropores on KGM film surface decrease or disappear, leading to more compact and uniform on the film surface. The structure of KGM-Boron complex is described as the coordination reaction between KGM and boron. The main reaction points are hydroxyl group on C（6） position of sugar as well as those on C（2） and C（3） positions of mannose with two kinds of complexes formation： B-K2 and KB-K. And KB-K mainly consists of g-b-m.

Construction of a chloroplast protein interaction network and functional mining of photosynthetic proteins in Arabidopsis thaliana

叶绿体是光合作用发生的一个典型植物细胞细胞器。在这研究，在 Arabidopsis thaliana 的 1 808 叶绿体核心蛋白质的一个总数被联合以前出版的研究和我们的自己的预言的结果可靠地识别。我们然后首先基于这些核心蛋白质相互作用构造了一个叶绿体蛋白质相互作用网络。网络有 22 包含了 2 的 925 蛋白质相互作用对 214 蛋白质。160 的一个总数以前， uncharacterized 蛋白质在这个网络被注解。光合的建筑群的子单元被模块化，并且在 photosystem 之中的功能的关系我(希腊语的第二十三个字母)， photosystem II ( PSII )， photosystem 的轻收获建筑群我( LHC 我)并且 photosystem 的轻收获建筑群( LHC II )我能在这个网络从预言的蛋白质相互作用被推出。我们进一步由酵母证实了在未知蛋白质 AT1G52220 和光合的子单元 PSI-D2 之间的一个相互作用二混血儿的分析。我们的叶绿体蛋白质相互作用网络应该为光合的蛋白质的功能的采矿和在在 Arabidopsis 的系统生物学水平的叶绿体相关的函数的调查是有用的。

Effects of Vitamin E on the Activities of Protective Enzymes and Membrane Lipid Peroxidation in Leymus Chinensis under Drought Stress

Leymus chinensis seedlings were treated with 0.05--10 mmol/L vitamin E under osmotic stress in the presence of polyethylene glycol（PEG） as the stress reagent. The effects of the different concentrations of exogenous vitamin E on the activities of SOD, POD and free proline, and the MDA contents under drought stress were examined so as to ascertain the mechanism of Leymus chinensis resistance to drought stress and explore the possible preventive measures. The results indicate that the activities of SOD and POD decreased but the free proline and MDA contents increased as drought stress was accentuated, showing an enhancement of oxidative stress that may cause a decline in membrane stabilization. However, the activities of SOD and POD and the free proline content increased, whereas the MDA content reduced in Leymus chinensis pretreated with vitamin E in comparison with that of the control. This indicates that exogenous vitamin E enhanced the antioxidation of Leymus chinensis seedlings. It suggests that cytomembrane can be protected from damage by increasing the free proline content and the activities of SOD and POD that result in enhancing the drought resistance of Leymus chinensis seedlings.

Elevation difference of Ca^(2+) levels in young leaf cells of bromegrass and induced cold-tolerant enhancement under different controlled chilling temperatures

The changes of Ca2＋ levels in young leaf cells of bromegrass under different controlled chilling temperatures were inves- tigated by an antimonite precipitation cytochemical method. The main results were as follows： under 25/20℃ （day/night） tempera- ture and 14 h photoperiod, electron-dense Ca2＋ antimonite precipitates, indicators of Ca2＋ localization, were mainly localized in the vacuoles, cell walls and intercellular spaces; few Ca2＋ deposits were observed in the cytosol and nuclei. After a 3℃ chilling treatment for 3 h, many Ca2＋ precipitates appeared in the cytosol and nuclei, indicating that Ca2＋ influx had occurred in the cytosol and nuclei. When the 3℃ treatment was prolonged to 8 h, more Ca2＋ deposits appeared in the nuclei and cytosol, but the amount of Ca2＋ deposits in both the cytosol and nuclei decreased markedly after a 24 h treatment and most Ca2＋ deposits were returned to the vacuoles and intercellular spaces after an 8 d treatment. When bromegrass was exposed to 7℃ for 3 h, the Ca2＋ distribution in the cells had no visible changes, compared with that of the 25/20℃ grown control plants. However, when the chilling treatment of 7℃ was prolonged to 8 h, a Ca2＋ influx occurred, where many Ca2＋ deposits were observed in the nuclei and cytosol. More Ca2＋ deposits appeared in the nuclei and cytosol after a 24 h treatment, but the amount of Ca2＋ deposits in the cytosol and nuclei was reduced markedly after an 8 d treatment. After a 14 d treatment, the remaining low level of Ca2＋ was recovered in both the cytosol and nuclei and the Ca2＋ deposits were again located in the vacuoles and the intercellular spaces. The dynamics of subcellular Ca2＋ localization in young leaf cells of bromegrass during a 12℃ chilling treatment were similar to those of the 7℃ treatment. Besides, the results showed that the frost tolerance ofbromegrass exposed to 3℃ for 8 d increased by 6℃, for 7℃ and 8 d by 4℃ and for 12℃ and 14 d by 3℃, compared with the controls. Finally, the relationship between different Ca2＋ dynamics and induced frost tolerance was also explored.

Interaction Between Cryptococcus laurentii,Monilinia fructicola,and Sweet Cherry Fruit at Different Temperatures

The present study was performed mainly to investigate the antagonist-pathogen-host interaction in wounds of the sweet cherry fruits. The antagonistic yeast Cryptococcus laurentii could significantly reduce the brown rot of the sweet cherry fruit caused by Monilinia fructicola at 25 and 1 ℃. The populations of yeast increased faster in the presence of the pathogen initially, but then decreased rapidly. In the fruits inoculated with M. fructicola alone or combined with C. laurentii, an induction of lipid peroxidation as well as activities of the antioxidant enzymes, such as, superoxide dismutases （SOD）, catalase （CAT）, and peroxidase （POD）, was observed. The isoenzyme pattern of polypheno/oxidase （PPO） changed greatly after the symptoms appeared, with new PPO isoforms being induced. By contrast, the induction of lipid peroxidation and activities of SOD, CAT, and POD were low, although no significant changes were found in the PPO isoenzyms in the fruits inoculated with antagonist C. laurentii alone. The inhibition of brown rot during the antagonist- pathogen-host interaction in wounds of the sweet cherry fruits was mainly on account of the stimulated growth of C. laurentii as well as the induction of antioxidant enzymes of the fruits by M. fructicola.

Proteome Analysis of Inhibitory Effect of Gadolinium on Sinorhizobium fredii

The inhibitory effect of gadolinium on Sinorhizobium fredii USDA 205 was studied on a global scale using twodimensional gel electrophoresis and MALDI-TOF MS. The results indicated that 22 proteins were significantly affected by 1 mmol · L^-1 Gd^3 ＋ treatment when compared with an untreated control. Among these proteins, nine were up-regulated and thirteen were down-regulated. The differently expressed proteins were classified into 8 functional categories based on their functions, including transporters, proteins for cellular defence, and proteins involved in metabolism.

Reversible Conformational Changes of PsbO Protein Detected by Terahertz Time-Domain Spectroscopy

We used a terahertz time-domain spectroscope （THz-TDS） to detect the reversible conformational changes of PsbO protein induced by N-bromosuccinimide and Guanidine Hydrochloride. The veracity and sensitivity are confirmed by the fluorescence emission spectra. The results demonstrate that THz-TDS has both advantages and disadvantages in monitoring the denaturation process of proteins, which is important in applying THz-TDS technique to studying biomolecules.

Studies on the Effect of Structure to Property Stability of Glucomannan

The effect of pH value on the kinds and number of Glucomannan hydrogen bonds was studied by experiments and molecular dynamics simulation, and that of the pH change on property and hydrogen bond was also analyzed. Ultimately, the impact of hydrogen bond change on its structure and property was discussed. The results of experiment and simulation were consistent with each other. In experiment, when pH〉7, peak strength of 1720 cm^-1 v-acetyl is reduced and peak of V-OH is widened; and in simulation, the function of hydrogen bond of KGM increases, the number of hydrogen bonds increases by 19 and two kinds of hydrogen bonds are formed. Potential energy reduces by 443.1 kJ/mol. Acetylate is an important group to affect the gel intensity which can be improved by the hydrogen bond interaction.

Cloning, E. coil Expression and Molecular Analysis of Amorpha-4,11-Diene Synthase from a High-Yield Strain of Artemisia annua L.

increasing demand of artemisinin in the treatment of malaria has placed substantial stress on the total artemisinin supplies world-wide, so more attention has been paid to increasing the content of artemisinin in the Artemisia annua L. plant. In this study, amorpha-4, 11-diene synthase （ADS） cDNA （ads1） and genomics gene （gads1） were cloned from a high-yield A. annua strain 001. The activity of ADS1 was confirmed by heterogeneous overexpression of ads I and in vitro enzymatic incubation. Reverse transcript-polymerase chain reaction results demonstrated that ads1 expressed in leaves, flowers and young stems, but not in roots. This organ-specific expression pattern of ads1 is consistent with that of artemisinin accumulation in the plant. The gads1 has a complex organization including seven exons and six introns, and belongs to class III terpene synthase. DNA gel blotting revealed that the ADS gene has at least four copies in the genome of strain 001. The higher copy numbers might be one of the reasons for its high artemisinin content.

Heterotrimeric G protein α subunit is involved in rice brassinosteroid response

Heterotrimeric G proteins are known to function as messengers in numerous signal transduction pathways.The nullmutation of RGA(rice heterotrimeric G protein α subunit),which encodes the α subunit of heterotrimeric G proteinin rice,causes severe dwarfism and reduced responsiveness to gibberellic acid in rice.However,less is known aboutheterotrimeric G protein in brassinosteroid(BR)signaling,one of the well-understood phytohormone pathways.In thepresent study,we used root elongation inhibition assay,lamina inclination assay and coleoptile elongation analysis todemonstrated reduced sensitivity of dl mutant plants(caused by the null mutation of RGA)to 24-epibrassinolide(24-epiBL),which belongs to brassinosteroids and plays a wide variety of roles in plant growth and development.Moreover,RGA transcript level was decreased in 24-epiBL-treated seedlings in a dose-dependent manner.Our results show thatRGA is involved in rice brassinosteroid response,which may be beneficial to elucidate the molecular mechanisms of Gprotein signaling and provide a novel perspective to understand BR signaling in higher plants.

Comparative Transcriptional Profiling and Preliminary Study on Heterosis Mechanism of Super-Hybrid Rice

Heterosis is a biological phenomenon whereby the offspring from two parents show improved and superior performance than either inbred parental lines. Hybrid rice is one of the most successful apotheoses in crops utilizing heterosis. Transcriptional profiling of F1 super-hybrid rice Liangyou-2186 and its parents by serial analysis of gene expression （SAGE） revealed 1183 differentially expressed genes （DGs）, among which DGs were found significantly enriched in pathways such as photosynthesis and carbon-fixation, and most of the key genes involved in the carbon-fixation pathway exhibited up-regulated expression in F1 hybrid rice. Moreover, increased catabolic activity of corresponding enzymes and photosynthetic efficiency were also detected, which combined to indicate that carbon fixation is enhanced in F1 hybrid, and might probably be associated with the yield vigor and heterosis in super-hybrid rice. By correlating DGs with yield-related quantitative trait loci （QTL）, a potential relationship between differential gene expression and phenotypic changes was also found. In addition, a regulatory network involving circadian-rhythms and light signaling pathways was also found, as previously reported in Arabidopsis, which suggest that such a network might also be related with heterosis in hybrid rice. Altogether, the present study provides another view for understanding the molecular mechanism underlying heterosis in rice.

Sexual Reproduction in Higher Plants I:Fertilization and the Initiation of Zygotic Program

Sexual plant reproduction is a critical developmental step in the life cycle of higher plants, to allow maternal and paternal genes to be transmitted in a highly regulated manner to the next generation. During evolution, a whole set of signal transduction machinery is developed by plants to ensure an error-free recognition between male and female gametes and initiation of zygotic program. In the past few years, the molecular machineries underlying this biological process have been elucidated, particularly on the importance of synergid cells in pollen tube guidance, the Ca^＋＋ spike as the immediate response of fertilization and the epigenetic regulation of parental gene expressions in early zygotic embryogenesis. This review outlines the most recent development in this area.

The brassinosteroid signal transduction pathway

类固醇作为在动物和植物表明分子工作。当动物类固醇荷尔蒙被抄写因素的原子受体家庭察觉时，在植物的 brassinosteroids (BR ) 被房间表面受体 kinase 察觉， BRI1。最近的研究证明了到 BRI1 的细胞外的域的那 BR 绑定与另一受体 kinase 导致 kinase 激活和 dimerization， BAK1。激活的 BRI1 或 BAK1 然后调整，可能间接地， BIN2 kinase 的活动或 BSU1 磷酸酶，它直接调整 phosphorylation 地位和二个相应抄写因素， BZR1 和 BES1 的原子累积。BZR1 和 BES1 直接绑在 BR 应答的基因的倡导者调整他们的表示。表明小径的 BR 为在一般来说由房间表面受体发信号的植物和类固醇发信号的两受体 kinase 成为了一个范例。

Involvement of DEG5 and DEG8 proteases in the turnover of the photosystem II reaction center D1 protein under heat stress in Arabidopsis thaliana

Deg5,deg8 and the double mutant,deg5deg8 of Arabidopsis thaliana were used to study the physiological role of the DEG proteases in the repair cycle of photosystem II (PSII) under heat stress. PSII activity in deg mutants showed increased sensitivity to heat stress, and the extent of this effect was greater in the double mutant, deg5deg8, than in the single mutants, deg5 and deg8. Degradation of the D1 protein was slower in the mutants than in the WT plants. Furthermore, the levels of other PSII reaction center proteins tested remained relatively stable in the mutant and WT plants following high-temperature treatment. Thus, our results indicate that DEG5 and DEG8 may have synergistic function in degradation of D1 protein under heat stress.

Physiological and Growth Responses of Tomato Progenies Harboring the Betaine Alhyde Dehydrogenase Gene to Salt Stress

The responses of five transgenic tomato （Lycopersicon esculentum Mill） lines containing the betaine aldehyde dehydrogenase （BADH） gene to salt stress were evaluated. Proline, betaine （N, N, N-trimethylglycine, hereafter betalne）, chlorophyll and ion contents, BADH activity, electrolyte leakage （EL）, and some growth parameters of the plants under 1.0% and 1.5% NaCl treatments were examined. The transgenic tomatoes had enhanced BADH activity and betaine content, compared to the wild type under stress conditions. Salt stress reduced chlorophyll contents to s higher extent in the wild type than in the transgenic plants. The wild type exhibited significantly higher proline content than the transgenic plants at 0.9% and 1.3% NaCh Cell membrane of the wild type was severely damaged as determined by higher EL under salinity stress. K^＋ and Ca^2＋ contents of all tested lines decreased under salt stress, but the transgenic plants showed a significantly higher accumulation of K^＋ and Ca^2＋ than the wild type. In contrast, the wild type had significantly higher CI- and Na^2＋ contents than the transgenic plants under salt stress. Although yield reduction among various lines varied, the wild type had the highest yield reduction. Fruit quality of the transgenic plants was better in comparison with the wild type as shown by a low ratio of blossom end rot fruits. The results show that the transgenic plants have improved salt tolerance over the wild type.

Overexpression of OsJAC1, a Lectin Gene, Suppresses the Coleoptile and Stem Elongation in Rice

Lectin plays an Important role In defense signaling In plants, but its function In plant growth and development is not well known. Previously, we cloneds rice （Oryza sativa L.） gene OsJAC1 encoding s msnnose-blndlng Jscslln-relsted lectln, and found that OsJAC1 was Jssmonlc acid （JA） Inducible. Here we cloned the promoter of OsJAC1, and GUS activity was detected In young roots, coleoptlles, sheaths, leaves, nodes of stems, stems, rschlses, pistils, stsmens and lemmss of OsJAC1：：GUS trsnsgenlc rice, suggesting that OsJAC1 Is s constitutive expression gene In rice. Moreover, OsJAC1-overexpressed （Ubi：：OsJAC1） rice showed dwarfism with shorter coleptlles resulting from the failure of cell elongation of coleoptlles. In addition, compared with coleoptlles of wild-type plants, those of OsJAC1 overexpresslon rice were more sensitive to JA treatment. These data revealed that, besides Its roles in defense response, lectin plays an Important role in rice growth and development.

Overexpression of OsRAA1 promotes flowering and hypocotyls elongation in Arabidopsis

Previously, OsRAA1, an AtFPF1 homologue gene, was found to play an important role in modulating rice root development. In the current study, OsRAA1 was overexpressed in Arabidopsis, and the transgenic plants showed early flowering and elongated hypocotyl phenotypes as compared with the wild-type under white-light conditions. The hypocotyls of transgenic lines were twice as long as those of wild-type plants under red-light conditions but were indistinguishable from those of the wild-type under blue and far-red light and darkness. In addition, the phenotypes of AtFPF1 transgenic lines were similar to those of OsRAA1 transgenic lines. These results suggested that OsRAA1/AtFPF1 protein is involved in regulating flowering time and plays an important role in the inhibition of hypocotyl elongation under continuous red light. The functions were preserved during the evolution.

Mutation of Residue Arginine^18 of Cytochrome b559 α-Subunit and its Effects on Photosystem Ⅱ Activities in Chlamydomonas reinhardtii

It has been known that arginine is used as the basic amino acid in the α-subunit of cytochrome bsss （Cyt bsss） except histidine. However, previous studies have focused on the function of histidine in the activities of photosystem （PS） Ⅱ and there are no reports regarding the structural and/or functional roles of arginine in PSll complexes. In the present study, two arginine18 （R18） mutants of Chlamydomonas reinhardtii were constructed using site-directed mutagenesis, in which R18 was replaced by glutamic acid （E） and glycine （G）. The results show that the oxygen evolution of the PSII complex in the R18G and R18E mutants was approximately 60% of wild-type （WT） levels and that, after irradiation at high light intensity, oxygen evolution for the PSll of mutants was reduced to zero compared with 40% in WT cells. The efficiency of light capture by PSll （Fv/Fm） of R18G and R18E mutants was approximately 42%-46% that of WT cells. Furthermore, levels of the α-subunit of Cyt bsss and PsbO proteins were reduced in thylakoid membranes compared with WT. Overall, these data suggest that R18 plays a significant role in helping Cyt bss9 maintain the structure of the PSll complex and its activity, although it is not directly bound to the heme group.

Characterization of a nitro-genase CrFe protein from a mutant UW3 of Azotobacter vinelandii grown on a Cr-containing medium

通过 DEAE-52 的列上的缺氧的层析， Q-Sepharose andSeph 压克力 S-200， CrFe 蛋白质准备从 UW3 被获得， Azotobactervinelandii 的异种，它在包含 Cr 媒介上成长了很好。与 MoFe 蛋白质(OP Av1 ) 相比 fromwild 类型紧张 OP，在准备的约 50% 蛋白质有类似的子单元作文并且与 OP Av1 的抗体有有免疫力的反应。准备有 C_2H_2- H~+-andN_2 的 -40 百分比(在 H~+ 减小活动在之间由差别表示了在 Ar 下面并且在 N_2 下面) 到那些的 OP Av1 和 OP Av1 的类似的电子对的减小活动。并且金属分析证明准备包含了 Fe， Cr 和瞬间。，在在约 450 nm 的准备的圆形的二色性(CD ) 光谱类似于 OP Av1 的出现在一样的 g 价值的 threeEPR 信号的相对紧张(g 约 4.3， 3.7 和 2.0 ) 是不同的。EPR-basedcalculated 结果显示出那(1 ) 到 Cr 的瞬间并且 Fe 到的比率(Cr+Mo ) 分别地， CrFe 蛋白质准备， 0.41 和 15 正在显示在准备，到 MoFe 蛋白质的比率包含 ofCr 蛋白质是大约 2.5；(2 ) 到 Fe 并且到准备的 Cr 的活动的比率分别地接近了活动的比率到 Fe 并且到 OP Av1 的瞬间；(3 ) EPR 的比率在到 CrFe 蛋白质的 Cr 的值大约到瞬间的约 83% 那些， 0% 和约 40% 的上述三 g 表明紧张。OP Av1，分别地。结果进一步显示 CrFe 蛋白质力量是一个新 ni-trogenase 部件我有在余因子由 Mn MoFe 蛋白质包括 metallocluster 到那些而不是瞬间的简单代替的类似的功能和结构的蛋白质。

Transcriptional regulation of wheat VER2 promoter in rice in response to abscisic acid,jasmonate,and light

VER2 is a key gene associated with vernalization process in winter wheat. The expression of VER2 can be induced by low temperature treatment. To further understand how the expression of this gene is mediated by various external and internal factors, different lengths of the VER2 promoter region have been transcriptionally fused with a reporter gene, green fluorescence protein （GFP）, and transformed into the model plant, rice （Oryza sativa L.）. Using confocal and Western blot analyses, we determined several possible response elements in the promoter region, which could sense ABA, JA, and other environmental cues.