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At least 145 records · Page 8Linked to original sources
PubMed2003

Identification of QTL for growth- and grain yield-related traits in rice across nine locations of Asia.

Rice double-haploid (DH) lines of an indica and japonica cross were grown at nine different locations across four countries in Asia. Genotype-by-environment (G x E) interaction analysis for 11 growth- and grain yield-related traits in nine locations was estimated by AMMI analysis. Maximum G x E interaction was exhibited for fertility percentage number of spikelets and grain yield. Plant height was least affected by environment, and the AMMI model explained a total of 76.2% of the interaction effect. Mean environment was computed by averaging the nine environments and subsequently analyzed with other environments to map quantitative trait loci (QTL). QTL controlling the 11 traits were detected by interval analysis using mapmaker/qtl. A threshold LOD of >/=3.20 was used to identify significant QTL. A total of 126 QTL were identified for the 11 traits across nine locations. Thirty-four QTL common in more than one environment were identified on ten chromosomes. A maximum of 44 QTL were detected for panicle length, and the maximum number of common QTL were detected for days to heading detected. A single locus for plant height (RZ730-RG810) had QTL common in all ten environments, confirming AMMI results that QTL for plant height were affected the least by environment, indicating the stability of the trait. Two QTL were detected for grain yield and 19 for thousand-grain weight in all DH lines. The number of QTL per trait per location ranged from zero to four. Clustering of the QTL for different traits at the same marker intervals was observed for plant height, panicle number, panicle length and spikelet number suggesting that pleiotropism and or tight linkage of different traits could be the possible reason for the congruence of several QTL. The many QTL detected by the same marker interval across environments indicate that QTL for most traits are stable and not essentially affected by environmental factors.

Asia↗
PubMed2006

Molecular cloning and functional characterization of psoralen synthase, the first committed monooxygenase of furanocoumarin biosynthesis.

Ammi majus L. accumulates linear furanocoumarins by cytochrome P450 (CYP)-dependent conversion of 6-prenylumbelliferone via (+)-marmesin to psoralen. Relevant activities, i.e. psoralen synthase, are induced rapidly from negligible background levels upon elicitation of A. majus cultures with transient maxima at 9-10 h and were recovered in labile microsomes. Expressed sequence tags were cloned from elicited Ammi cells by a nested DD-RT-PCR strategy with CYP-specific primers, and full-size cDNAs were generated from those fragments correlated in abundance with the induction profile of furanocoumarin-specific activities. One of these cDNAs representing a transcript of maximal abundance at 4 h of elicitation was assigned CYP71AJ1. Functional expression in Escherichia coli or yeast cells initially failed but was accomplished eventually in yeast cells after swapping the N-terminal membrane anchor domain with that of CYP73A1. The recombinant enzyme was identified as psoralen synthase with narrow substrate specificity for (+)-marmesin. Psoralen synthase catalyzes a unique carbon-chain cleavage reaction concomitantly releasing acetone by syn-elimination. Related plants, i.e. Heracleum mantegazzianum, are known to produce both linear and angular furanocoumarins by analogous conversion of 8-prenylumbelliferone via (+)-columbianetin to angelicin, and it was suggested that angelicin synthase has evolved from psoralen synthase. However, (+)-columbianetin failed as substrate but competitively inhibited psoralen synthase activity. Analogy modeling and docked solutions defined the conditions for high affinity substrate binding and predicted the minimal requirements to accommodate (+)-columbianetin in the active site cavity. The studies suggested that several point mutations are necessary to pave the road toward angelicin synthase evolution.

Amino Acid Sequence↗
PubMed2004

Use of trial clustering to study QTL x environment effects for grain yield and related traits in maize.

A population of 300 F(3:4) lines derived from the cross between maize inbred lines F2 and F252 was evaluated for testcross value in a large range of environmental conditions (11 different locations in 2 years: 1995 and 1996) in order to study (1) the magnitude of genotype x environment and (2) the stability of quantitative trait loci (QTL) effects. Several agronomic traits were measured: dry grain yield (DGY), kernel weight, average number of kernels per plant, silking date (SD) and grain moisture at harvest. A large genotype x environment interaction was found, particularly for DGY. A hierarchical classification of trials and an additive main effects and multiplicative interaction (AMMI) model were carried out. Both methods led to the conclusion that trials could be partitioned into three groups consistent with (1) the year of experiment and (2) the water availability (irrigated vs non-irrigated) for the trials sown in 1995. QTL detection was carried out for all the traits in the different groups of trials. Between 9 and 15 QTL were detected for each trait. QTL x group and QTL x trial effects were tested and proved significant for a large proportion of QTL. QTL detection was also performed on coordinates on the first two principal components (PC) of the AMMI model. PC QTL were generally detected in areas where QTL x group and QTL x trial interactions were significant. A region located on chromosome 8 near an SD QTL seemed to play a key role in DGY stability. Our results confirm the key role of water availability and flowering earliness on grain yield stability in maize.

Chromosome Mapping↗
PubMed2006

Evaluation of similarity measures for reconstruction-based registration in image-guided radiotherapy and surgery.

PURPOSE: A promising patient positioning technique is based on registering computed tomographic (CT) or magnetic resonance (MR) images to cone-beam CT images (CBCT). The extra radiation dose delivered to the patient can be substantially reduced by using fewer projections. This approach results in lower quality CBCT images. The purpose of this study is to evaluate a number of similarity measures (SMs) suitable for registration of CT or MR images to low-quality CBCTs. METHODS AND MATERIALS: Using the recently proposed evaluation protocol, we evaluated nine SMs with respect to pretreatment imaging modalities, number of two-dimensional (2D) images used for reconstruction, and number of reconstruction iterations. The image database consisted of 100 X-ray and corresponding CT and MR images of two vertebral columns. RESULTS: Using a higher number of 2D projections or reconstruction iterations results in higher accuracy and slightly lower robustness. The similarity measures that behaved the best also yielded the best registration results. The most appropriate similarity measure was the asymmetric multi-feature mutual information (AMMI). CONCLUSIONS: The evaluation protocol proved to be a valuable tool for selecting the best similarity measure for the reconstruction-based registration. The results indicate that accurate and robust CT/CBCT or even MR/CBCT registrations are possible if the AMMI similarity measure is used.

Algorithms↗
PubMed1998

Inhibition of metabolic activation of the promutagens, benzo[a]pyrene, 2-aminofluorene and 2-aminoanthracene by furanochromones in Salmonella typhimurium.

Khellin, a naturally occurring furanochromone (Ammi visnaga fruits), inhibited the mutagenicity of the promutagens benzo[a]pyrene, 2-aminofluorene and 2-aminoanthracene in Salmonella typhimurium TA98. The effect varied greatly and depended on the S9 fraction used. Cytosolic activation of 2-aminoanthracene was also inhibited. Khellin produced no effect or only weak activity against the direct acting mutagens 2-nitrofluorene, 4-nitro-o-phenylenediamine, 1-nitropyrene and ethylmethane sulfonate (in TA100). Daunomycin mutagenicity was inhibited to a greater extent. Visnagin was more toxic, but showed similar effects. Khellol and its glucoside were inactive against all the mutagens tested. We conclude that khellin acts as an inhibitor or the microsomal cytochrome P450 sub-enzymes analogous to the related furanocoumarins and is also capable of inhibiting cytosolic enzymes. The extract from Ammi visnaga fruits showed a higher inhibition potency than khellin alone against 2-aminoanthracene, 1-nitropyrene and daunomycin. This might be due to additional inhibitors, e.g. coumarins, or to the synergistic effects of accompanying compounds.

Animals↗
PubMed1991

Molecular cloning, induction and taxonomic distribution of caffeoyl-CoA 3-O-methyltransferase, an enzyme involved in disease resistance.

Trans-Caffeoyl-CoA 3-O-methyltransferase is involved in the reinforcement of the plant cell wall under conditions that trigger the disease resistance response (Pakusch, A.-E., Kneusel, R.E., and Matern, U. (1989) Arch. Biochem. Biophys. 271, 488-494). Partial amino acid sequences of the enzyme from cultured parsley cells that had been treated with a crude elicitor were identified (Pakusch, A.-E., Matern, U., and Schiltz, E. (1991) Plant Physiol. 95, 137-143), and corresponding degenerated oligonucleotides of 29- and 30-nucleotide length were synthesized. Northern hybridizations with these probes revealed one specific RNA band, and the amount of this RNA appeared to be transiently induced upon elicitation of the cells. De novo enzyme synthesis was confirmed by Western blotting experiments using a specific antiserum. The time course of induction closely followed the pattern observed for phenylalanine ammonia-lyase and suggested the operational coordination of the methyltransferase with the general phenylpropanoid pathway in vivo. Full size cDNA of 1.258 kilobases was isolated in lambda gt11, sequenced and found to contain a remarkably long 5'-untranslated leader sequence followed by an open reading frame that codes for a 241-residue polypeptide representing the 27-kDa subunit of the native, dimeric parsley enzyme. Almost no homology was found to protein sequences filed in data banks. Southern hybridization with genomic DNA suggested that only one or two copies of the respective gene(s) are present in the parsley genome. Caffeoyl-CoA-specific methyltransferase activity was demonstrated in taxonomically widely diverse plants such as Dianthus caryophyllus (Caryophyllaceae), Carthamus tinctorius (Asteraceae) or Daucus carota, and Ammi majus (Apiaceae) where it is commonly induced by elicitor treatment. In Northern blots with RNA from Ammi or Daucus, parsley cDNA hybridized specifically to one band comparable in size to the parsley RNA, whereas Dianthus and Carthamus appear to code for slightly larger RNAs (roughly 1.45 and 1.3 kilobases, respectively). Slot-blot hybridizations revealed in all instances the rapid and transient increase of mRNA levels in response to elicitation. This emphasizes the integral role of the enzyme in disease resistance expression in plants far beyond parsley and also illustrates a new physiological context for the induction of 4-coumarate:CoA ligase.

Amino Acid Sequence↗
PubMed2026

Grain protein and yield stability study in rainfed durum wheat RILs.

Developing durum wheat cultivars with stable grain yield across diverse environments remains a key breeding objective. This study evaluated 118 recombinant inbred lines (RILs) derived from a cross between the drought-adapted cultivar 'Zardak' (Triticum durum) and the landrace 'Iran-249' (T. turanicum) with desirable seed characteristics, across four heterogeneous rainfed environments in Italy and Iran. The assessment focused on grain yield (GY) and grain protein content (GPC) stability. Combined analysis of variance revealed significant (p&#x2009;<&#x2009;0.01) effects for genotype, environment, and their interaction for both traits. Line ZD-050 showed the highest GY (3.91 t ha&#x207b;&#xb9;), while ZD-032 had the highest GPC (14.27%). Stability analysis using parametric and non-parametric methods, along with AMMI and GGE biplot modeling, identified ZD-050 as among the most promising genotypes according to yield-integrating and dynamic-stability approaches. This line showed high grain yield in methods such as the Superiority Index and Kang's rank-sum, although stability rankings differed across the used methods. This line maintained superior yield, demonstrated broad adaptability across environments, and had moderate protein levels, identifying it as an optimal candidate for breeding programs targeting yield stability and wide adaptation under rainfed conditions.

Triticum↗
PubMed1954

Ammoidin (xanthotoxin) in the treatment of vitiligo.

Eighteen patients with vitiligo were treated with two crystalline substances, xanthotoxin (Ammoidin) and imperatorin (Ammidin) from the plant Ammi majus. Four patients improved more than 50 per cent. One had complete cure, but depigmentation recurred after a few months. Six patients had moderate improvement (less than 50 per cent), three had slight repigmentation, and in five cases there was no improvement. These results are similar to those reported by other investigators.Pronounced local inflammatory reactions are to be expected after exposure to ultraviolet light in nearly all patients treated with xanthotoxin. In one case prolonged sensitivity to sunlight, manifest by vesiculating dermatitis, occurred.

Adult↗
PubMed1999

Effect of active molluscicidal component of spices on different enzyme activities and biogenic amine levels in the nervous tissue of Lymnaea acuminata.

In vivo exposure of Lymnaea acuminata to thymol and [6]-gingerol (active molluscicidal components of Trachyspermum ammi and Zingiber officinale, respectively) indicates that they significantly alter acetylcholinesterase, lactic dehydrogenase, succinic dehydrogenase and cyto-oxidase activity in the nervous -tissue of snails. In vitro exposure showed that, except for acetylcholinesterase and lactic dehydrogenase, no significant changes were observed in cyto-oxidase and succinic dehydrogenase activity in the nervous tissue of L. acuminata. Sublethal exposure to thymol and [6]-gingerol reduced the levels of 5-hydroxytryptamine (5-HT) and dopamine (DA) in the nervous tissue of L. acuminata. There was, however, no significant change in the level of 5-hydroxy indol acetic acid (5-HIAA). Thymol and [6]-gingerol thus affects all the known neurotransmission mechanisms in the snail either separately or through a complex interaction between the different neurotransmitters. This may account for their toxicity to snails.

Acetylcholinesterase↗
PubMed2000

Inhibitory effects of sudanese medicinal plant extracts on hepatitis C virus (HCV) protease.

One hundred fifty-two methanol and water extracts of different parts of 71 plants commonly used in Sudanese traditional medicine were screened for their inhibitory effects on hepatitis C virus (HCV) protease (PR) using in vitro assay methods. Thirty-four extracts showed significant inhibitory activity (>/=60% inhibition at 100 microg/mL). Of these, eight extracts, methanol extracts of Acacia nilotica, Boswellia carterii, Embelia schimperi, Quercus infectoria, Trachyspermum ammi and water extracts of Piper cubeba, Q. infectoria and Syzygium aromaticum, were the most active (>/=90% inhibition at 100 microg/mL). From the E. schimperi extract, two benzoquinones, embelin (I) and 5-O-methylembelin (II), were isolated and found as potent HCV-PR inhibitors with IC(50) values of 21 and 46 microM, respectively. Inhibitory activities of derivatives of I against HCV-PR as well as their effects on other serine proteases were also investigated.

Chromatography, High Pressure Liquid↗
PubMed2000

Membrane proteomics: use of additive main effects with multiplicative interaction model to classify plasma membrane proteins according to their solubility and electrophoretic properties.

Recent efforts at the proteomic level were employed to describe the protein equipment of the plasma membrane of the model plant Arabidopsis thaliana. These studies had revealed that the plasma membrane is rich in extrinsic proteins but came up against two major problems: (i) few hydrophobic proteins were recovered in two-dimensional electrophoresis gels, and (ii) many plasma membrane proteins had no known function or were unknown in the database despite extensive sequencing of the Arabidopsis genome. In this paper, several methods expected to enrich a membrane sample in hydrophobic proteins were compared. The optimization of solubilization procedures revealed that the detergent to be used depends on the lipid content of the sample. The corresponding proteomes were compared with the statistical model AMMI (additive main effects with multiplicative interaction) that aimed at regrouping proteins according to their solubility and electrophoretic properties. Distinct groups emerged from this analysis and the identification of proteins in each group allowed us to assign specific features to several of them. For instance, two of these groups regrouped very hydrophobic proteins, one group contained V-ATPase subunits, another group contained proteins with one transmembrane domain as well as proteins known to interact with membrane proteins. This study provides methodological tools to study particular classes of plasma membrane proteins and should be applicable to other cellular membranes.

Amino Acid Sequence↗
PubMed1976

Multiliter production and immunochemical cross-reactivity of plant tissue culture antigens.

Cells of short ragweed suspension culture were successfully propagated in a multiliter fermentor. Proteins were isolated from tissue cultures (short ragweed, cantaloupe, marigold, and Ammi) and plants (short ragweed pollen, cantaloupe fruit, and marigold flowers) by ammonium sulfate precipitation, cross-linked dextran gel filtration, and anion-exchange chromatography. Some fractions elicited allergenic responses in ragweed-sensitive patients but not in ragweed-nonsensitive control patients. Double-immunodiffusion analysis of these fractions showed their nonidentity with short ragweed antigen E.

Allergens↗