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991.
Varun Kumar Rajinder Singh Chauhan Chanderdeep Tandon 《Journal of plant biochemistry and biotechnology.》2017,26(1):1-13
Picrorhiza genus is emerging as an important paradigm for herbal drug formulations due to its versatile iridoid glycosides exhibition and robustness in the treatment of diverse infections including hepatic amoebiasis, cancer, malaria, ulcerative colitis and cerebral ischemia reperfusion injury. Owing to the superiority of these bioactivities, iridoid glycosides from Picrorhiza have become a hot research area over the years. A metabolic pathway for the formation of iridoid glycosides has been proposed. However, some enzymes and genes of this route are still unidentified and demand the enumeration of facilitating pathways contributing to the biosynthesis of iridoid glycosides. This review summarizes the current knowledge of all naturally occurring iridoid glycosides from Picrorhiza, their biosynthesis and pharmacological capabilities which could provide the insight into metabolic regulation and the basis for the development of new drugs. 相似文献
992.
In this study, we evaluated the damage caused in the field by Tibraca limbativentris Stål adults at different levels of infestation (0, 1, 2, and 4 stink bugs) per three rice plants during three growth stages (V8, V13, and R4 stages) of upland rice cultivated in southwestern of Pará State, Amazon Rainforest region, Brazil. Heading time (panicle exertion) was affected by T. limbativentris infestations mainly in the vegetative stage and the whiteheads percentage in treatments ranged from 18.2 to 38%. The dead hearts percentages varied between 0 and 21.5%, and the mean number of primary branches (ramifications) ranged from 5.9?±?0.4 to 12.3?±?0.2. The number of empty spikelets was only affected in infestations with four insects/three plants, while the quantity of filled grains per panicle was affected only when infestations occurred during the vegetative stage. The total number of spikelets (filled?+?empty) per panicle decreased significantly in all phenological stages, and the percentage of damage ranged from 17 to 44% among treatments. Based on the proportion of damage observed, we suggest doubling the number of insects presently used as action threshold to 2 and 4 stink bugs per 15 stalks sampled for the vegetative stage, and of 1 or 2 stink bugs per 15 stalks sampled at the beginning of reproductive stage (R3/R4). Also, the field should be monitored during the entire vegetative stage, since most damage was observed in this phenological stage. 相似文献
993.
Non-aquatic reproductive modes have evolved among frogs possibly favored by some advantages such as the avoidance of aquatic predators. These reproductive modes, however, make the egg clutches susceptible to terrestrial predators, among which Diptera larvae are some of the most harmful. The present work reports the predation by phorid flies of 22 egg clutches of Phyllomedusa iheringii Boulenger in the South of Brazil. Phorid specimens were identified as Megaselia bruchiana (Borgmeier & Schmitz) and Megaselia necrophaga (Enderlein), species that were reported previously to be associated with ants and dead beetles, respectively. Frog-feeding in these species is hypothesized to be use of an alternative seasonal food source. We amend the diagnoses of both Megaselia species and provide new illustrations to facilitate their identification. We also describe the male of M. bruchiana for the first time and associate males with females of both species. 相似文献
994.
Feng Zhou Shuang Liu Zhaohui Hu Tingyun Kuang Harald Paulsen Chunhong Yang 《Photosynthesis research》2009,99(3):185-193
The non-bilayer lipid monogalactosyldiacylglycerol (MGDG) is the most abundant type of lipid in the thylakoid membrane and
plays an important role in regulating the structure and function of photosynthetic membrane proteins. In this study, we have
reconstituted the isolated major light-harvesting complexes of photosystem II (PSII) (LHCIIb) and a preparation consisting
of PSII core complexes and minor LHCII of PSII (PSIICC) into liposomes that consisted of digalactosyldiacylglycerol (DGDG),
sulfoquinovosyldiacylglycerol (SQDG) and phosphatidylglycerol (PG), with or without MGDG. Transmission electron microscopy
and freeze-fracture studies showed unilamellar proteoliposomes, and demonstrated that most of the MGDG is incorporated into
bilayer structures. The impact of MGDG on the functional interaction between LHCIIb and PSIICC was investigated by low temperature
(77 K) fluorescence emission spectra and the photochemical activity of PSII. The additional incorporation of LHCIIb into liposomes
containing PSIICC markedly increased oxygen evolution of PSIICC. Excitation at 480 nm of chlorophyll (Chl) b in LHCIIb stimulated a characteristic fluorescence emission of the Chl a in PSII (684.2 nm), rather than that of the Chl a in LHCIIb (680 nm) in the LHCIIb–PSIICC proteoliposomes, which indicated that the energy was transferred from LHCIIb to PSIICC
in liposome membranes. Increasing the percentage of MGDG in the PSIICC–LHCIIb proteoliposomes enhanced the photochemical activity
of PSII, due to a more efficient energy transfer from LHCIIb to PSIICC and, thus, an enlarged antenna cross section of PSII. 相似文献
995.
An hydroponic culture was conducted to investigate the effect of saline stress on the essential oil and fatty acid composition
of Tunisian coriander (Coriandrum sativum L.) roots. Ten days old coriander seedlings were treated during 3 weeks with different NaCl concentrations (0, 25, 50 and
75 mM). Roots volatile components and fatty acids were analyzed. The essential oil yield was 0.06% in the control, on the
basis of dry matter weight, and did not changed at low concentration (25 mM), while it increased significantly with increasing
NaCl concentrations to reach 0.12 and 0.21% at 50 and 75 mM NaCl, respectively. The major volatile component was (E)-2-dodecenal with 52% of total essential oil constituents, followed by decanal, dodecanal, (E)-2-tridecenal and (E)-2-dodecenal. Further, the amount of these compounds was affected differently by the NaCl level. Total fatty acid amount
of coriander roots increased significantly only with 50 and 75 mM NaCl. Three major fatty acids: linoleic (43%), oleic (25.5%)
and palmitic (21.6%) were identified. Linoleic acid amount remains unchanged at 25 mM, while it increased with raising NaCl
concentrations. However, oleic acid amount decreased only at 25 mM and no effect was observed at 50 and 75 mM. Fatty acid
percentages were differently affected by salt. The oleic/linoleic ratio was reduced with raising NaCl concentrations. 相似文献
996.
Bettina Maccagnani Francesca Giacomello Marco Fanti Davide Gobbin Stefano Maini Gino Angeli 《BioControl》2009,54(1):123-133
The efficiency of two pollinators, Apis mellifera L. (Hymenoptera: Apidae) and the mason bee Osmia cornuta (Latreille) (Hymenoptera: Megachilidae), as carriers of biocontrol agents (BCA) from flower to flower (secondary colonisation) was investigated on apple cv ‘Golden Delicious’. The BCA tested was Bacillus subtilis, strain BD170 (Biopro®) developed for the control of the ‘fire blight’ caused by Erwinia amylovora (Burril) Winslow et al. The two insect species were studied as secondary BCA carriers on apple plants in pots under net screened tunnels. Their behaviour and capacity to deposit the BCA in the most receptive flower parts were compared both by washing, diluting and plating the flower organs on a recovery medium and by means of PCR analyses based on a molecular marker. O. cornuta showed better performances with respect to A. mellifera. For the field trials, pollinators were introduced in four apple orchards. During apple’s flowering, the BD170 (100 g hl?l) was sprayed once in two fields, and twice in the others. The pollinators’ efficacy in carrying the BCA from sprayed flowers to the stigmas of newly opened ones at different times after the spray treatment was evaluated. The detection of the BCA was performed by PCR analysis. The percentages of positive PCR flower samples were higher in the internal treated areas of the fields with respect to the external untreated ones, but the high colonisation level found in the latter and in the flowers opened in both areas several days after the treatment(s) demonstrated that pollinators can play an important role as secondary carriers. 相似文献
997.
Caberg JH Hubert P Herman L Herfs M Roncarati P Boniver J Delvenne P 《Cancer immunology, immunotherapy : CII》2009,58(1):39-47
Human papillomavirus (HPV) infection, particularly type 16, is causally associated with cancer of the uterine cervix. The
persistence or progression of cervical lesions suggests that viral antigens are not adequately presented to the immune system.
This hypothesis is reinforced by the observation that most squamous intraepithelial lesions (SILs) show quantitative and functional
alterations of Langerhans cells (LC). The infiltration of immature LC in the squamous epithelium is mainly controlled by Macrophage
Inflammatory Protein 3α/CCL20. After having shown that CCL20 production is altered in HPV-transformed keratinocytes (KC),
the possible role of HPV16 E6 and E7 viral oncoproteins in the reduced CCL20 levels observed in SILs was investigated by silencing
HPV16 E6 and E7 oncogenes by RNA interference (siRNA). This treatment not only increased CCL20 secretion but also resulted
in the modulation of NF-κB p50, p52 and p65 precursor localization. Moreover, silencing of E6 and E7 oncogenes in HPV16-transformed
KC induced a significantly higher migratory capacity of LC in a Boyden chamber assay and in an in vitro formed (pre)neoplastic
epithelium reminiscent of high-grade SILs. Anti-CCL20 neutralizing antibody experiments showed that the increased migration
of LC is due to the re-expression of CCL20 in E6 and E7 siRNA transfected KC. These data suggest that HPV16 E6/E7-induced
down-regulation of CCL20 observed during the cervical carcinogenesis may contribute to a diminished capacity of the immune
system to control HPV infection.
P. Hubert and J. H. Caberg contributed equally to this work. 相似文献
998.
One of the biggest challenges facing evolutionary biologists is to identify and understand loci that explain fitness variation
in natural populations. This review describes how genetic (linkage) mapping with single nucleotide polymorphism (SNP) markers
can lead to great progress in this area. Strategies for SNP discovery and SNP genotyping are described and an overview of
how to model SNP genotype information in mapping studies is presented. Finally, the opportunity afforded by new generation
sequencing and typing technologies to map fitness genes by genome-wide association studies is discussed. 相似文献
999.
Soltani F Mosaffa F Iranshahi M Karimi G Malekaneh M Haghighi F Behravan J 《Cell biology and toxicology》2009,25(3):291-296
The protective properties of a prenylated coumarin, umbelliprenin (UMB), on the human lymphocytes DNA lesions were tested.
Lymphocytes were isolated from blood samples taken from healthy volunteers. DNA breaks and resistance to H2O2-induced damage were measured using a single-cell microgel electrophoresis technique under alkaline conditions (comet assay).
Human lymphocytes were incubated in UMB (10, 25, 50, 100, 200, and 400 μM) alone or a combination of different concentrations
of UMB (10, 25, 50, 100, 200, and 400 μM) and 25 μM H2O2. Untreated cells, ascorbic acid (AA; 25, 50, 100, 200, and 400 μM) and H2O2 (25 μM) were considered as negative control, positive control, and the standard antioxidant agent for our study, respectively.
Single cells were analyzed with “TriTek Cometscore version 1.5” software. The DNA damage was expressed as percent tail DNA.
UMB exhibited a concentration-dependent increase in protection activity against DNA damage induced by 25 μM H2O2 (from 67.28% to 39.17%). The antigenotoxic activity of AA, in the range 0–50 μM, was greater than that of UMB. However, no
significant difference (p > 0.05) in the protective activity was found between UMB and AA at concentrations of approximately higher than 50 μM. 相似文献
1000.
Artificial cross between two genetically different populations of Japanese Misgurnus loach was made to examine the reproductive capacity of the artificial inter-populational hybrid females. Ploidy status and
microsatellite genotypes of the eggs laid by these hybrids were inferred from those determined in progenies developed by normal
fertilization with haploid loach sperm, induced gynogenesis with UV-irradiated goldfish sperm and/or hybridization with intact
goldfish sperm. Some hybrid females laid unreduced diploid eggs genetically identical to the mother. However, these diploid
eggs could not develop by spontaneous gynogenesis, but grow to triploid by incorporation of a sperm nucleus. Other hybrid
females laid haploid eggs together with diploid eggs and/or various aneuploid and polyploid eggs. Thus, a disruption of normal
meiosis occurred in inter-populational hybrid females. The results suggested that the two populations should be so distant
as to give rise to atypical formation of unreduced and other unusual eggs in their hybrids. 相似文献