作者机构：
[Hao, Lin; Xia, Shitou; Li, Xin] Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada.;[Zhu, Zhaohai; Xia, Shitou; Zhang, Yuelin] Natl Inst Biol Sci, Beijing 102206, Peoples R China.;[Xia, Shitou; Xiao, Langtao] Hunan Agr Univ, Hunan Prov Key Lab Phytohormones & Growth & Dev, Changsha 410128, Hunan, Peoples R China.;[Li, Xin; Chen, Jin-Gui] Univ British Columbia, Dept Bot, Vancouver, BC V6T 1Z4, Canada.
通讯机构：
[Li, Xin] U;Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada.
摘要：
Systemic acquired resistance (SAR) is a plant immune response induced by local necrotizing pathogen infections. Expression of SAR in Arabidopsis (Arabidopsis thaliana) plants correlates with accumulation of salicylic acid (SA) and up-regulation of Pathogenesis-Related (PR) genes. SA is an essential and sufficient signal for SAR. In a genetic screen to search for negative regulators of PR gene expression and SAR, we found a new mutant that is hypersensitive to SA and exhibits enhanced induction of PR genes and resistance against the virulent oomycete Hyaloperonospora arabidopsidis Noco2. The enhanced pathogen resistance in the mutant is Nonexpressor of PR genes1 independent. The mutant gene was identified by map-based cloning, and it encodes a protein with high homology to Replication Factor C Subunit3 (RFC3) of yeast and other eukaryotes; thus, the mutant was named rfc3-1. rfc3-1 mutant plants are smaller than wild-type plants and have narrower leaves and petals. On the epidermis of true leaves, there are fewer cells in rfc3-1 compared with the wild type. Cell production rate is reduced in rfc3-1 mutant roots, indicating that the mutated RFC3 slows down cell proliferation. As Replication Factor C is involved in replication-coupled chromatin assembly, our data suggest that chromatin assembly and remodeling may play important roles in the negative control of PR gene expression and SAR.
摘要：
Xiao, H., JunFang, Lu, X., Liu, Z., Chen, X., Liu, J., Su, J., Yi, J. and Sun, Z. 2009. Protective effect of soluble fiber from Undaria pinnatifida on vascular endothelium in hypercholesterolemic rabbits. Can. J. Anim. Sci. 89: 361-367. Dietary fiber could improve endothelial function and abnormal production of nitric oxide (NO) and elevated endothelin-1 (ET-1) concentration induce endothelial dysfunction. In the present study, we tested the effect of soluble fiber extracted from Undaria pinnatifida (UP) on endothelial function and NO and ET-1 production in hypercholesterolemic rabbits. After treatment with UP soluble fiber (5 or 10%) for 8 wk, endothelium-dependent vasorelaxation in isolated aortic rings, the concentrations of NO and ET-1 and malondialdehyde (MDA), and the expression of endothelial NO synthase (eNOS) gene were measured. The UP soluble fiber (5 or 10%) treatment significantly attenuated the impairment of endotheliumdependent vasorelaxation concomitantly with increase of plasma NO concentration and expression of aortic endothelial nitric oxide synthase (eNOS), reduction of plasma MDA level and ET-1 concentration and aortic ET-1 concentration. The present study indicates that the protective effects of UP soluble fiber on endothelium-mediated vasorelaxation may be related to an improved NO production and a reduced ET-1 concentration in hypercholesterolemic rabbits.
摘要：
Weak organic acids including tartaric and citric acids were applied to a typical paddy soil in southern China to test their effects on rice in the field for three years. Their effects were also compared with top dressings of the two acids, basal application of diammonium acid phosphate, calcium carbonate, and the control. The results showed that rice grain yield of the citric acid treatment was significantly higher than that of the control and the same difference was also observed for the filled spikelets per panicle. There were no significant difference among all the treatments and the control on the accumulation of above ground dry matter. However the root dry matter, length, peroxidase activity, and white root number of citric acid treatment were significantly higher than that of the control, while no significant differences among other treatments were observed. Basal application of citric acid played a positive role on this soil.
期刊：
International Journal of Mass Spectrometry,2009年286(2-3):112-121 ISSN：1387-3806
通讯作者：
Liang, Yi-Zeng
作者机构：
[Ouyang, Yong-Zhong; Xu, Xiaona; Zhang, Liangxiao; Luo, Xiao; Liang, Yi-Zeng; Tang, Zhonghai] Cent S Univ, Coll Chem & Chem Engn, Res Ctr Modernizat Chinese Med, Changsha 410083, Peoples R China.;[Li, Shuhua] Nanjing Univ, Key Lab Mesoscop Chem MOE, Dept Chem, Inst Theoret & Computat Chem, Nanjing 210093, Peoples R China.;[Tang, Zhonghai] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.;[Xu, Xiaona] Univ S China, Coll Chem & Chem Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Liang, Yi-Zeng] C;Cent S Univ, Coll Chem & Chem Engn, Res Ctr Modernizat Chinese Med, Changsha 410083, Peoples R China.
关键词：
Characteristic fragmentation mechanism;Initial ionization site;Radical site;Atomic spin density;Ionization energy
摘要：
The characteristic fragmentation mechanisms of the derivatives of tryptophan and tryptamine are investigated by the density functional theory (DFT) at the B3LYP/6-31+G (d, p) level. The main primary alpha-cleavage fragmentation has been predicted through determining the initial ionization site by calculated spin density of molecular radical cation and the variation of molecular structures from neutral to cationic form. The results show that the more intensive base peak produced by main primary alpha-cleavage fragmentation predicted in the present agrees well with those of experimental mass spectra, which is useful for characterizing the fragmentation mechanisms of such indole alkaloids. More importantly, the novel method for determining the most likely initial ionization site proposed in this study is prior to that based on the ionization energy (IE). It will play an important role in unraveling the mechanisms of radical-driven fragmentation not only for small molecules, but also for gas-phase peptides occurring in electron capture dissociation (ECD), electron transfer dissociation (ETD), or low-energy CID of peptide radical cations. However, this study is inappropriate for negative systems. (C) 2009 Elsevier B.V. All rights reserved.
摘要：
The F-box protein CORONATINE INSENSITIVE1 (COI1) plays a central role in jasmonate (JA) signaling and is required for all JA responses in Arabidopsis (Arabidopsis thaliana). To dissect JA signal transduction, we isolated the partially suppressing coi1 (psc1) mutant, which partially suppressed coi1 insensitivity to JA inhibition of root growth. The psc1 mutant partially restored JA sensitivity in coi1-2 background and displayed JA hypersensitivity in wild-type COI1 background. Genetic mapping, sequence analysis, and complementation tests revealed that psc1 is a leaky mutation of DWARF4 (DWF4) that encodes a key enzyme in brassinosteroid (BR) biosynthesis. Physiological analysis showed that an application of exogenous BR eliminated the partial restoration of JA sensitivity by psc1 in coi1-2 background and the JA hypersensitivity of psc1 in wild-type COI1 background. Exogenous BR also attenuated JA inhibition of root growth in the wild type. In addition, the expression of DWF4 was inhibited by JA, and this inhibition was dependent on COI1. These results indicate that (1) BR is involved in JA signaling and negatively regulates JA inhibition of root growth, and (2) the DWF4 is down-regulated by JA and is located downstream of COI1 in the JA-signaling pathway.
摘要：
Comparison of the volatile constituents of different parts of Cortex magnolia officinalis by GC-MS combined with chemometric resolution method Volatile compositions of different parts (stem, branch and root barks) of Cortex magnolia officinalis, cultivated in China, were investigated for the first time by GC-MS with the help of heuristic evolving latent projection (HELP). Identification of components was conducted by similarity matching to NIST mass library but also assisted by comparison of temperature-programmed retention indices (PTRIs) with the data web available. A total of 90, 82 and 76 volatile compounds in the essential oils of the three samples taken from the same batch aforementioned were qualitatively and quantitatively determined, representing 84.03, 83.68 and 83.10% of the total content, respectively. Among the constituents determined, there were 50 components coexisting. Eudesmol and its isomers were shown to be the principal compounds in the studied samples, accounting for 47.66, 36.74 and 36.31%, respectively. The three kinds of isomers (a-, band c-eudesmol) in houpo volatile oils have been tentatively qualified and quantified simultaneously for the first time. By comparative analysis, significant qualitative and semi-quantitative differences and similarities were observed among the three samples. The results achieved provide a scientific evidence for further exploitation of Magnolia bark and clinical medication.
摘要：
Transposons are effective mutagens alternative to T-DNA for the generation of insertional mutants in many plant species including those whose transformation is inefficient. The current strategies of transposon tagging are usually slow and labor-intensive and yield low frequency of tagged lines. We have constructed a series of transposon tagging vectors based on three approaches: (i) AcTPase controlled by glucocorticoid binding domain/VP16 acidic activation domain/Gal4 DNA-binding domain (GVG) chemical-inducible expression system; (ii) deletion of AcTPase via Cre-lox site-specific recombination that was initially triggered by Ds excision; and (iii) suppression of early transposition events in transformed rice callus through a dual-functional hygromycin resistance gene in a novel Ds element (HPT-Ds). We tested these vectors in transgenic rice and characterized the transposition events. Our results showed that these vectors are useful resources for functional genomics of rice and other crop plants. The vectors are freely available for the community. 2009 Institute of Botany, the Chinese Academy of Sciences.
摘要：
Treatment of potato (Solanum tuberosum L.) with chlorocholine chloride (CCC) applied twice as a foliar spray 25 and 30 days after planting has shown to decrease shoot and stolon growth but increase tuber yield. However, the regulatory role of CCC on translocation of recently fixed photoassimilates into different parts of potato plants has not been fully illustrated. In this study, C-14-isotope labelling technique was used to estimate the photosynthetic capacity and photoassimilate partitioning among leaves, stems, roots + stolons, and tubers of potted potatoes treated with 1.5 g l(-1) CCC. CCC treatment significantly increased tuber dry mass but reduced leaf dry mass. CCC-treated leaves had significantly higher chlorophyll and carotenoid contents and assimilated 22.0% more (CO2)-C-14 per leaf dry mass than the controls. Compared with the control, CCC treatment reduced the translocation of C-14-photoassimilates into leaves, steins and roots + stolons but increased that into tubers. CCC-treated leaves exported 14.6% more C-14-photoassimilates into other parts of the plants. In addition, CCC treatment reduced C-14-Soluble sugarand C-14-starch accumulation in leaves and stems but enhanced them in tubers and roots + stolons. Collectively, the results indicate that CCC treatment significantly improves the photosynthetic capacity of potato leaves and promotes photoassimilates partitioning into tubers thereby enhancing tuber growth. (C) 2008 Elsevier B.V. All rights reserved.
摘要：
Jingzhaotoxin-34 (JZTX-34) is a 35-residue polypeptide from the venom of Chinese tarantula Chilobrachys jingzhao. Our previous work reported its full-length cDNA sequence encoding a precursor with 87 residues. In this study we report the protein expression and biological function characterization. The toxin was efficiently expressed by the secretary pathway in yeast. Under whole-cell patch-clamp mode, the expressed JZTX-34 was able to inhibit tetrodotoxin-sensitive (TTX-S) sodium currents (IC50 similar to 85 nM) while having no significant effects on tetrodotoxin-resistant (TTX-R) sodium currents on rat dorsal root ganglion neurons. The inhibition of TTX-S sodium channels was completely reversed by strong depolarization (+120 mV). Toxin treatment altered neither channel activation and inactivation kinetics nor recovery rate from inactivation. However, it is interesting to note that in contrast to huwentoxin-IV, a recently identified receptor site-4 toxin from Ornithoctonus huwena venom, 100 nM JZTX-34 caused a negative shift of steady-state inactivation curve of TTX-S sodium channels by approximately 10 mV. The results indicated that JZTX-34 might inhibit mammalian sensory neuronal sodium channels through a mechanism similar to HWTX-IV by trapping the 1154 voltage sensor in the resting conformation, but their binding sites should not overlay completely. (C) 2009 Elsevier Inc. All rights reserved.
摘要：
Expression profiles of nine rice heat shock protein genes (OsHSPs) were analyzed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The nine genes exhibited distinctive expression in different organs. Expression of nine OsHSP genes was affected differentially by abiotic stresses and abscisic acid (ABA). All nine OsHSP genes were induced strongly by heat shock treatment, whereas none of them were induced by cold. The transcripts of OsHSP80.2, OsHSP71.1 and OsHSP23.7 were increased during salt tress treatment. Expression of OsHSP80.2 and OsHSP24.1 genes were enhanced while treated with 10% PEG. Only OsHSP71.1 was induced by ABA while OsHSP24.1 was suppressed by ABA. These observations imply that the nine OsHSP genes may play different roles in plant development and abiotic stress responses.
摘要：
Effects of chlorocholine chloride (CCC) on phytohormones and photosynthetic characteristics of Zhongshu 3, a potato (Solanum tuberosum L.) variety widely cultivated in south China, were studied by foliar CCC application on 24 and 28 days after emergence, that is, at the tuber initiation stage. It was found that on 42 days after emergence, that is, at the tuber bulking stage, spraying CCC increased indolacetic-3-acid (IAA) and zeatin (Z) contents but decreased abscisic acid (ABA) content in leaves. The content ratios of IAA/Z, IAA/ABA, Z/ABA, and (IAA + Z)/ABA in leaves treated with CCC were higher than those of the control. CCC plays a prominent regulating role in the photosynthesis of Zhongshu 3. The net photosynthetic rate (P
n), stomatal conductance (G
s), intercellular CO2 concentration (C
i), and transpiration rate (T
r) of treated leaves were superior to those of controls at the tuber bulking stage. CCC markedly increased tuber yield and quality. The contents of sucrose and starch in tubers treated with CCC increased at the end of the vegetation period, whereas the contents of reducing sugars and solanine decreased. CCC at 2.0 g L−1 was found to be the most effective concentration. Collectively, the results of this research identify phytohomonal metabolism and photosynthetic physiology of potato leaves as processes affected early after application of CCC resulting in significantly improved increases in tuber yield and quality.
摘要：
Phalaenopsis frequently exhibits bud drop during production and in response to adverse postharvest conditions. The effect of exogenous ethylene on bud drop of mini Phalaenopsis was studied and ethylene sensitivity of four cultivars was compared. Water content, membrane permeability and ABA (abscisic acid) content in floral buds and flowers were determined after ethylene treatment. Exogenous ethylene induced flower bud drop in all tested Phalaenopsis cultivars and the different cultivars showed distinct differences in ethylene sensitivity. The cultivar Sogo ‘Vivien’ exhibited the highest bud drop, water loss and change in membrane permeability in floral petals, while Sogo ‘Berry’ showed the lowest sensitivity. The ethylene inhibitor 1-MCP (1-methylcyclopropene) reduced ethylene-induced floral bud drop in the cultivar Sogo ‘Yenlin’. ABA content in floral buds was increased in response to ethylene and 1-MCP pretreatment inhibited the ethylene-induced increase in ABA levels efficiently. This finding suggests that the observed increase in ABA content during bud drop was mediated by ethylene. The interaction between ABA and ethylene is discussed.
