作者机构：
湖南农业大学,生物科学技术学院,湖南,长沙,410128;英国萨里大学,生物医学与分子科学学院,食品营养与安全研究中心,吉尔福德,萨里郡,CU2 7XH;[CLIFFORD Michael N.] 萨里大学;[WANG Zheng] 湖南农业大学
通讯机构：
College of Bioscience and Biotechnology, Hunan Agricultural University, China
关键词：
LC-MSn
摘要：
To investigate the chlorogenic acids resources in Eucommia ulmoides Olive leaves, Lonicera japonica Thunb. leaves and Houttuynla cordata Thunb. leaves, methanolic extracts of these three materials have been analysed qualitatively for chlorogenic acids and their derivatives by structure-diagnostic LC-MSn. Three monocaffeoylquinic acids (3-CQA, 4-CQA, 5-CQA) were detected. 5-CQA dominated this subgroup in Eucommia ulmoides Olive and Lonicera japonica Thunb. leaves, but 3-CQA and 4-CQA dominated this subgroup of chlorogenic acids in the leaves of Houttuynla cordata Thunb. Caffeoylquinic acid-glycosides were detected for the first time from Eucommia ulmoides leaves. 5-FQA was found in Lonicera japonica Thunb. leaves, and 3-FQA and 4-pCoQA have been identified in Houttuynla cordata Thunb. This is the first report of the chlorogenic acid profile in Houttuynla cordata Thunb. The comparatively unusual profile of caffeoylquinic acids in Houttuynla cordata Thunb. makes it a convenient source of 3-CQA and 4-CQA that are not commercially available.
摘要：
Laboratory batch experiments were conducted to study arsenic （As） removal from a naturally contaminated soil using phosphoric acid （H_3PO_4） and potassium dihydrogen phosphate （KHEPO_4）. Both H_3PO_4 and KHEPO_4 proved to reduce toxicity of the soil in terms of soil As content, attaining more than 20% As removal at a concentration of 200 mmol/L. At the same time, acidification of soil and dissolution of soil components （Ca, Mg, and Si） resulted from using these two extractants, especially H_3PO_4. The effectiveness of these two extractants could be attributed to the replacement of As by phosphate ions （PO~(3-)_4）. The function of H_3PO_4 as an acid to dissolve soil components had little effects on As removal. KH_2PO_4 almost removed as much As as H_3PO_4, but it did not result in serious damage to soils, indicating that it was a more promising extractant. The results of a kinetic study showed that As removal reached equilibrium after incubation for 360 rain, but dissolution of soil components, especially Mg and Ca, was very rapid. Therefore dissolution of soil components would be inevitable if As was further removed. Elovich model best described the kinetic data of As removal among the four models used in the kinetic study.
摘要：
Shikonin and its derivatives are formed in large amounts in dark-cultured Onosma paniculatum cells. In order to isolate and identify the genes regulating shikonin biosynthesis, we constructed and characterized a full-length-enriched cDNA Library of dark-cultured cells by using the SMART (Switching Mechanism At 5'-end of RNA Transcript) cDNA synthesis and LD-PCR (tong-distance PCR) strategies. The titer of the primary cDNA library was 1.04 x 10(6) pfu/mL with a recombination rate of 99.60%. Most of the cDNA inserts ranged from 1.0 to 2.5 kb, and 78.33% of the 76 randomly selected clones contained full-length coding regions. Expression analysis of randomly selected genes by small scale microarray revealed that 23 genes were down-regulated, including 17 genes with known functions, 2 genes with putative functions, and 4 novel genes, and that 3 genes were up-regulated (two-fold) in cells cultured under white tight as compared with those cultured in the dark. Interestingly, two of the down-regulated genes, encoding aci-reductone dioxygenase (ARD)-like protein and ethylene responsive factor (ERF), are involved in ethylene biosynthesis and signal transduction, implying that ethylene might play an important role as a signal molecule in tight-regulated shikonin formation. These data contribute to a better understanding of light-involvement in regulating the formation of plant secondary metabolites. (C) 2007 Elsevier GmbH. All rights reserved.
摘要：
The photosensitive resveratrol was successfully encapsulated in yeast cells for the first time, as characterized by FT-IR spectra, fluorescence and confocal micrographs of the yeast cells, resveratrol and microcapsules. The release characteristic of the obtained yeast-encapsulated resveratrol in simulated gastric fluid was evaluated, and its storage stability as a powder was investigated at 25 degrees C/75% relative humidity (RH), 25 degrees C/90% RH and 60 degrees C under the laboratory fluorescent lighting conditions (ca. 300 lx) or in the dark. Also, the scavenging capacity of yeast-encapsulated resveratrol on DPPH radical was compared with that of non-encapsulated resveratrol. It could be demonstrated clearly that no chemical changes occurred during the encapsulation. Besides, the DPPH radical-scavenging activity increased after the encapsulation. In addition, the yeast-encapsulated resveratrol exhibited good stability, and its bioavailability was enhanced as a result of increased solubility of resveratrol and sustained releasing. (c) 2007 Elsevier B.V. All rights reserved.
摘要：
The transcription factor WRKY70 was previously reported to be a common component in salicylic acid (SA) and jasmonate (JA) mediated signal pathways in Arabidopsis. Here, we present that the inactivation of the WRKY70 gene in wrky70-1 mutant does not alter the responses of both JA and SA, and that wrky70 mutation is unable to restore the coi1 mutant in JA responses. However, overexpression of WRKY70 reduces JA responses such as expression of JA-induced genes and JA-inhibitory root growth, and activates expression of SA-inducible PR1. These data indicate that the WRKY70 is important but not indispensable for JA and SA signaling, and that other regulators may display the redundant role with WRKY70 in modulation of JA and SA responses in Arabidopsis. Furthermore, we showed that JA inhibits expression of WRKY70 and PR1 by both COI1-dependent and COI1-independent pathways.
摘要：
Ubiquitin ligases play a central role in determining the specificity of the ubiquitination system by selecting a myriad of appropriate candidate proteins for modification. The U-box is a recently identified, ubiquitin ligase activity-related protein domain that shows greater presence in plants than in other organisms. In this study, we identified 77 putative U-box proteins from the rice genome using a battery of whole genome analysis algorithms. Most of the U-box protein genes are expressed, as supported by the identification of their corresponding expressed sequence tags (ESTs), full-length cDNAs, or massively parallel signature sequencing (MPSS) tags. Using the same algorithms, we identified 61 U-box proteins from the Arabidopsis genome. The rice and Arabidopsis U-box proteins were classified into nine major classes based on their domain compositions. Comparison between rice and Arabidopsis U-box proteins indicates that the majority of rice and Arabidopsis U-box proteins have the same domain organizations. The inferred phylogeny established the homology between rice and Arabidopsis U-box/ARM proteins. Cell death assay using the rice protoplast system suggests that one rice U-box gene, OsPUB51, might act as a negative regulator of cell death signaling. In addition, the selected U-box proteins were found to be functional E3 ubiquitin ligases. The identification and analysis of rice U-box proteins hereby at the genomic level will help functionally characterize this class of E3 ubiquitin ligase in the future.
摘要：
Using high-yielding hybrid rice ＇Liangyoupeijiu＇ （LYP9） and hybrid rice ＇Shanyou 63＇ （SY63） as the experimental materials and using ~(14)C radio-autography, the photosynthetic capacities and distribution of photosynthates in flag leaf blades and sheaths of LYP9 were studied. The results showed that net photosynthetic rates （P_n） of the flag leaf blades and sheaths of LYP9 were much higher than those of SY63; the light transmissivity rates （LT） measured at the medium height of the flag leaf sheaths and the penultimate leaf sheaths were also significantly higher than those of SY63. The incipient activities, total activities and activation percentages of Rubisco in the flag leaf blade and sheath of LYP9 were all higher than those of SY63. The photosynthate transport rate in the sheaths of LYP9, and the quantity of photosynthate transported to the spikes and transformed to economic yield of LYP9 were all higher than those of SY63. The photosynthates produced by the sheaths were mainly transported to spike to make a certain contribution （about 15%） to yield.
摘要：
Replication factor C （RFC）, consisting of one large subunit and four small subunits, is an important factor involved in DNA replication and repair mechanisms as well as cell proliferation. The subunit 1 of Arabidopsis RFC （AtRFC1） is a homologue of p140, the large subunit of human RFC. Three T-DNA insertion mutant lines of AtRFC1, i.e. rfc1-1, rfc1-2 and rfc1-3, with insertion mutations located in exons 16 and 19, and the promoter region respectively were verified. These mutations caused defects in embryogenesis and led to embryo and seed abortion. Transformation of wild type AtRFC1 gene into rfcl mutant alleles reverted the mutant phenotypes, suggesting that AtRFC1 plays an important role in embryo development in Arabidopsis thaliana.
