bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arabidopsis Transcriptome Changes in Response to Phloem-Feeding Silverleaf Whitefly Nymphs. Similarities and Distinctions in Responses to Aphids
Authors: Kempema Louisa A. , Cui Xinping , Holzer Frances M. , Walling Linda L. 
Published: December 2006

Abstract
Phloem-feeding pests cause extensive crop damage throughout the world, yet little is understood about how plants perceive and defend themselves from these threats. The silverleaf whitefly (SLWF; Bemisia tabaci type B) is a good model for studying phloem-feeding insect-plant interactions, as SLWF nymphs cause little wounding and have a long, continuous interaction with the plant. Using the Affymetrix ATH1 GeneChip to monitor the Arabidopsis (Arabidopsis thaliana) transcriptome, 700 transcripts were found to be up-regulated and 556 down-regulated by SLWF nymphs. Closer examination of the regulation of secondary metabolite (glucosinolate) and defense pathway genes after SLWF-instar feeding shows that responses were qualitatively and quantitatively different from chewing insects and aphids. In addition to the RNA profile distinctions, analysis of SLWF performance on wild-type and phytoalexin-deficient4 (pad4) mutants suggests aphid and SLWF interactions with Arabidopsis were distinct. While pad4-1 mutants were more susceptible to aphids, SLWF development on pad4-1 and wild-type plants was similar. Furthermore, although jasmonic acid genes were repressed and salicylic acid-regulated genes were induced after SLWF feeding, cytological staining of SLWF-infested tissue showed that pathogen defenses, such as localized cell death and hydrogen peroxide accumulation, were not observed. Like aphid and fungal pathogens, callose synthase gene RNAs accumulated and callose deposition was observed in SLWF-infested tissue. These results provide a more comprehensive understanding of phloem-feeding insect-plant interactions and distinguish SLWF global responses.
MPB2C, a Microtubule-Associated Plant Factor, Is Required for Microtubular Accumulation of Tobacco Mosaic Virus Movement Protein in Plants
Authors: Curin Mirela , Ojangu Eve-Ly , Trutnyeva Kateryna , Ilau Birger , Truve Erkki , Waigmann Elisabeth 
Published: December 2006

AbstractMovement protein binding 2C (MPB2C) is a plant endogenous microtubule-associated protein previously identified as an interaction partner of tobacco (Nicotiana tabacum) mosaic virus movement protein (TMV-MP). In this work, the role of MPB2C in cell-to-cell transport of TMV-MP, viral spread of TMV, and subcellular localization of TMV-MP was examined. To this end, plants with reduced MPB2C levels were generated by a gene-silencing strategy. Local and systemic spread of TMV and cell-to-cell movement of TMV-MP were unimpaired in MPB2C-silenced plants as compared to nonsilenced plants, indicating that MPB2C is not required for intercellular transport of TMV-MP itself or spread of TMV. However, a clear change in subcellular distribution of TMV-MP characterized by a nearly complete loss of microtubular localization was observed in MPB2C-silenced plants. This result shows that the MPB2C is a central player in determining the complex subcellular localization of TMV-MP, in particular its microtubular accumulation, a phenomenon that has been frequently observed and whose role is still under discussion. Clearly, MPB2C mediated accumulation of TMV-MP at microtubules is not required for intercellular spread but may be a means to withdraw the TMV-MP from the cell-to-cell transport pathway.
Desiccation and Zinc Binding Induce Transition of Tomato Abscisic Acid Stress Ripening 1, a Water Stress- and Salt Stress-Regulated Plant-Specific Protein, from Unfolded to Folded State
Authors: Goldgur Yehuda , Rom Slava , Ghirlando Rodolfo , Shkolnik Doron , Shadrin Natalia , Konrad Zvia , Bar-Zvi Dudy 
Published: December 2006

Abstract
Abscisic acid stress ripening 1 (ASR1) is a low molecular weight plant-specific protein encoded by an abiotic stress-regulated gene. Overexpression of ASR1 in transgenic plants increases their salt tolerance. The ASR1 protein possesses a zinc-dependent DNA-binding activity. The DNA-binding site was mapped to the central part of the polypeptide using truncated forms of the protein. Two additional zinc-binding sites were shown to be localized at the amino terminus of the polypeptide. ASR1 protein is presumed to be an intrinsically unstructured protein using a number of prediction algorithms. The degree of order of ASR1 was determined experimentally using nontagged recombinant protein expressed in Escherichia coli and purified to homogeneity. Purified ASR1 was shown to be unfolded using dynamic light scattering, gel filtration, microcalorimetry, circular dichroism, and Fourier transform infrared spectrometry. The protein was shown to be monomeric by analytical ultracentrifugation. Addition of zinc ions resulted in a global change in ASR1 structure from monomer to homodimer. Upon binding of zinc ions, the protein becomes ordered as shown by Fourier transform infrared spectrometry and microcalorimetry, concomitant with dimerization. Tomato (Solanum lycopersicum) leaf soluble ASR1 is unstructured in the absence of added zinc and gains structure upon binding of the metal ion. The effect of zinc binding on ASR1 folding and dimerization is discussed.
A Multidrug Resistance Transporter in Magnaporthe Is Required for Host Penetration and for Survival during Oxidative Stress
Authors: Sun Chuan Bao , Suresh Angayarkanni , Deng Yi Zhen , Naqvi Naweed I. 
Published: December 2006

Abstract
In prokaryotes and eukaryotes, multidrug resistance (MDR) transporters use energy-dependent efflux action to regulate the intracellular levels of antibiotic or xenobiotic compounds. Using mutational analysis of ABC3, we define an important role for such MDR-based efflux during the host penetration step of Magnaporthe grisea pathogenesis. Mutants lacking ABC3 were completely nonpathogenic but were surprisingly capable of penetrating thin cellophane membranes to some extent. The inability of abc3Δ to penetrate the host surface was most likely a consequence of excessive buildup of peroxide and accumulation of an inhibitory metabolite(s) within the mutant appressoria. Treatment with antioxidants partially suppressed the host penetration defects in the abc3Δ mutant. abc3Δ was highly sensitive to oxidative stress and was unable to survive the host environment and invasive growth conditions. ABC3 transcript levels were redox-regulated, and on host surfaces, the activation of ABC3 occurred during initial stages of blast disease establishment. An Abc3-green fluorescent protein fusion localized to the plasma membrane in early appressoria (and in penetration hyphae) but became predominantly vacuolar during appressorial maturity. We propose that ABC3 function helps Magnaporthe to cope with cytotoxicity and oxidative stress within the appressoria during early stages of infection-related morphogenesis and likely imparts defense against certain antagonistic and xenobiotic conditions encountered during pathogenic development.
Defects in CTP:PHOSPHORYLETHANOLAMINE CYTIDYLYLTRANSFERASE Affect Embryonic and Postembryonic Development in Arabidopsis
Authors: Mizoi Junya , Nakamura Masanobu , Nishida Ikuo 
Published: December 2006

Abstract
A TILLING strategy (for targeting-induced local-scale lesions in genomes) was used in Arabidopsis thaliana to isolate mutants of a gene encoding CTP:PHOSPHORYLETHANOLAMINE CYTIDYLYLTRANSFERASE (PECT; EC 2.7.7.14), a rate-limiting enzyme in phosphatidylethanolamine biosynthesis. A null mutation, pect1-6, caused embryo abortion before the octant stage. However, reciprocal crosses revealed that pect1-6 caused no significant gametophytic defect. In pect1-4, PECT activity was decreased by 74%. Growth was generally normal in these mutants, despite delays in embryo maturation and reduced fertility. At low temperatures, however, homozygotic pect1-4 plants displayed dwarfism. PECT activity was decreased by 47% in heterozygotic pect1-6 plants and by 80% in pect1-4/pect1-6 F1 plants, which also displayed a small but significant decrease of phosphatidylethanolamine and a reciprocal increase in phosphatidylcholine. These lipid changes were fully reversed by wild-type PECT1 expression. pect1-4/pect1-6 F1 plants displayed severe dwarfism, tissue abnormalities, and low fertility, which was attributable in part to inhibition of anther, embryo, and ovule development, as was the reduced fertility of pect1-4 seedlings. PECT1 cDNA expression under the control of an inducible promoter partially rectified the mutant phenotypes observed in pect1-4/pect1-6 F1 seedlings, indicating that malfunctions in different tissues have a synergistic effect on the mutant phenotypes.
Dynamics of a Mobile RNA of Potato Involved in a Long-Distance Signaling Pathway
Authors: Banerjee Anjan K. , Chatterjee Mithu , Yu Yueyue , Suh Sang-Gon , Miller W. Allen , Hannapel David J. 
Published: December 2006

AbstractBEL1-like transcription factors interact with Knotted1 types to regulate numerous developmental processes. In potato (Solanum tuberosum), the BEL1 transcription factor St BEL5 and its protein partner POTH1 regulate tuber formation by mediating hormone levels in the stolon tip. The accumulation of St BEL5 RNA increases in response to short-day photoperiods, inductive for tuber formation. RNA detection methods and heterografting experiments demonstrate that BEL5 transcripts are present in phloem cells and move across a graft union to localize in stolon tips, the site of tuber induction. This movement of RNA to stolon tips is correlated with enhanced tuber production. Overexpression of BEL5 transcripts that include the untranslated sequences of the BEL5 transcript endows transgenic lines with the capacity to overcome the inhibitory effects of long days on tuber formation. Addition of the untranslated regions leads to preferential accumulation of the BEL5 RNA in stolon tips under short-day conditions. Using a leaf-specific promoter, the movement of BEL5 RNA to stolon tips was facilitated by a short-day photoperiod, and this movement was correlated with enhanced tuber production. These results implicate the transcripts of St BEL5 in a long-distance signaling pathway that are delivered to the target organ via the phloem stream.
C‐terminal loop of Streptomyces phospholipase D has multiple functional roles
Authors: Uesugi Yoshiko , Arima Jiro , Iwabuchi Masaki , Hatanaka Tadashi 
Published: December 2006

AbstractWe have recently shown that two flexible loops of Streptomyces phospholipase D (PLD) affect the catalytic reaction of the enzyme by a comparative study of chimeric PLDs. Gly188 and Asp191 of PLD from Streptomyces septatus TH‐2 (TH‐2PLD) were identified as the key amino acid residues involved in the recognition of phospholipids. In the present study, we further investigated the relationship between a C‐terminal loop of TH‐2PLD and PLD activities to elucidate the reaction mechanism and the recognition of the substrate. By analyzing chimeras and mutants in terms of hydrolytic and transphosphatidylation activities, Ala426 and Lys438 of TH‐2PLD were identified as the residues associated with the activities. We found that Gly188 and Asp191 recognized substrate forms, whereas residues Ala426 and Lys438 enhanced transphosphatidylation and hydrolysis activities regardless of the substrate form. By substituting Ala426 and Lys438 with Phe and His, respectively, the mutant showed not only higher activities but also higher thermostability and tolerance against organic solvents. Furthermore, the mutant also improved the selectivity of the transphosphatidylation activity. The residues Ala426 and Lys438 were located in the C‐terminal flexible loop of Streptomyces PLD separate from the highly conserved catalytic HxKxxxxD motifs. We demonstrated that this C‐terminal loop, which formed the entrance of the active well, has multiple functional roles in Streptomyces PLD.
Crystal structure of the BTB domain from the LRF/ZBTB7 transcriptional regulator
Authors: Stogios Peter J. , Chen Lu , Privé Gilbert G. 
Published: December 2006

AbstractBTB‐zinc finger (BTB‐ZF) proteins are transcription regulators with roles in development, differentiation, and oncogenesis. In these proteins, the BTB domain (also known as the POZ domain) is a protein–protein interaction motif that contains a dimerization interface, a possible oligomerization surface, and surfaces for interactions with other factors, including nuclear co‐repressors and histone deacetylases. The BTB‐ZF protein LRF (also known as ZBTB7, FBI‐1, OCZF, and Pokemon) is a master regulator of oncogenesis, and represses the transcription of a variety of important genes, including the ARF, c‐fos, and c‐myc oncogenes and extracellular matrix genes. We determined the crystal structure of the BTB domain from human LRF to 2.1 Å and observed the canonical BTB homodimer fold. However, novel features are apparent on the surface of the homodimer, including differences in the lateral groove and charged pocket regions. The residues that line the lateral groove have little similarity with the equivalent residues from the BCL6 BTB domain, and we show that the 17‐residue BCL6 Binding Domain (BBD) from the SMRT co‐repressor does not bind to the LRF BTB domain.
Physical State of Cellulose During Ripening of Peach
Authors: STERLING CLARENCE 
Published: December 2006

SUMMARYCell walls of ripening fruits of peach were purified of a large part of their non‐cellulosic components and examined with X‐ray techniques. Small, but distinct, increases in micellar size, and perhaps in percentages of crystallinity, are a function of the maturation process. These increases are interpreted as evidence of a limited degradation of cellulose (broadly defined).
The Xanthophylls of Tomatoes
Authors: CURL A. LAURENCE 
Published: December 2006

SUMMARYThe carotenoids of ripe tomatoes were found to contain about 6% xanthophylls; the composition of the latter was about 15% monols, 49% diols, 4% monoepoxide diols, 22% diepoxide diols, and 11% polyols. The diol and polyol xanthophylls were much like those of green leaves, with lutein the major pigment, somewhat smaller amounts of violaxanthin and neoxanthin, and much smaller amounts of zeaxanthin, lutein 5,6‐epoxide, and several others.The monol fraction contained lycoxanthin and “monol 487” (which may be 3‐hydroxy‐delta‐carotene), together with substances tentatively identified as polycis isomers of lycoxanthin, rubixanthin, and “monol 487.”
COMPARISON OF VALENCIA ESSENTIAL OIL FROM CALIFORNIA, FLORIDA AND ISRAEL
Authors: LIFSHITZ A. , STANLEY W. L. , STEPAK Y. 
Published: December 2006

SUMMARYSamples of essential oils from California, Florida and Israel, all of Valencia orange, were analyzed for percent area in GLC of C8, C9 and C10 aldehydes, as well as for their total carbonyl content. It was found that the aldehyde patterns of the Florida and Israel oils are similar and are both different from that of the California oil. As for the carbonyl content, the 3 oils were found to be statistically different from each other.
PHOSPHOCREATINE AND NUCLEOTIDE CHANGES IN PIG LONGISSIMUS MUSCLE DURING THE DEVELOPMENT OF RIGOR MORTIS UNDER CONTROLLED ENVIRONMENTAL CONDITIONS
Authors: SCHMIDT G. R. , BRISKEY E. J. 
Published: December 2006

SUMMARYThis study was conducted to compare the depletion of phosphocreatine (PC) and nucleotides (ATP and ADP) in strips of muscle which had been used for extensibility meesurements in the rigorometer with control strips of muscle which had been held unrestrained in the same environment. There were no significant differences in PC and ATP between the rigorometer and control strips. Rigorometer strips from “Stress‐susceptible” pigs had less rapid and less extensive depletion of ADP than did control strips from the same animals. It appeared that extensibility remained in the tissue after the A TP had been depleted, but not after AOP reached a low level.
CHANGES IN TENSION AND CERTAIN METABOLITES DURING THE DEVELOPMENT OF RIGOR IVIORTIS IN SELECTED RED AND WHITE SKELETAL MUSCLES
Authors: SCHMIDT G. R. , CASSENS R. G. , BRISKEY E. J. 
Published: December 2006

SUMMARYThe relative time course of rigor mortis was compared in the vastus lateralis (red) and the longissimus (white) muscle from untreated and magnesium sulfate injected “Stress‐resistant” Chester White pigs and “stress‐susceptible” Poland China pigs. In untreated animals the white muscle had a shorter time course of rigor mortis than did the red muscle. This difference disappeared when the animals ware injected ante‐mortem with magnesium sulfate although both muscles from injected animals had a slower development of rigor mortis than the same muscles in control animals. Either magnesium sulfate had more of an effect on white than on red muscle post‐mortem, or the differences between the post‐mortem rates of glycolysis of red and white muscles were significantly minimized when struggle and stimulation associated with death had been eliminated. Red muscles in magnesium sulfate injected pigs developed more tension post‐mortem than did white muscles. The development of isometric tension reached its maximum as the muscle lost all of its extensibility. Muscle from “stress‐susceptible” pigs had a shorter time course of rigor mortis than the corresponding muscle from “stress‐resistant” pigs of the same treatment. This difference occurred even when the two groups started with the same level of phosphocreatine and lactic acid post‐exsanguination, as is the case when treated with magnesium sulfate. Therefore, even though magnesium treatment can retard glycolysis sufficiently to prevent the development of the PSE condition (Sair et al., 1970), it does not necessarily standardize the postmortem changes in all skeletal muscles of all pigs.
RELATIONSHIP OF CALCIUM UPTAKE BY THE SARCOPLASMIC RETICULUM TO TENSION DEVELOPMENT AND RIGOR MORTIS IN STRIATED MUSCLE
Authors: SCHMIDT G. R. , CASSENS R. G. , BRISKEY E. J. 
Published: December 2006

SUMMARYConcentrations of phosphocreatine (PC), adenosine triphosphate (ATP) and lactic acid were determined in longissimus muscle from 7 “stress‐resistant” Chester White pigs and 8 “stress‐susceptible” Poland China pigs at several intervals during the loss of extensibility postmortem. Calcium‐binding ability of the sarcoplasmic reticulum and postmortem tension development of longissimus muscle also ware determined. Loss of extensibility was completed sooner in longissimus muscle from stress‐susceptible pigs than from stress‐resistant pigs. For the most part, longissimus muscle samples from stress‐susceptible pigs had lower (P <.05) levels of PC and ATP and higher (P < .05) levels of lactic acid at identical stages of change in extensibility than did samples from stress‐resistant pigs. At identical stages of change in extensibility in “fast” and “slow‐glycolyzing” muscles, there were no significant differences in the ability of the sarcoplasmic reticulum preparations to bind calcium or in the muscle's ability to develop isometric tension.
A NEW EXTRACTION METHOD FOR DETERMINING 2‐THIOBARBITURIC ACID VALUES OF PORK AND BEEF DURING STORAGE
Authors: WITTE VERNON C. , KRAUSE GARY F. , BAILEY MILTON E. 
Published: December 2006

SUMMARY2‐Thiobarbituric acid (TBA) values of raw pork were determined by distillation and extraction methods and those of raw beef were determined by the latter method during storage at 4° and –20°C. TBA values of these tissues were low compared to values usually reported for cooked tissue from these animals in similar environments. There were significant animal differences in TBA values of beef and pork; there were significant changes in TBA values of these tissues during storage at 4°C, but changes during storage at –20°C were insignificant. pH and TBA values were inversely related. Mathematical relationships between TBA values of pork and beef during storage at 4°C. between TBA values and pH and between results obtained by the two procedures for determining TBA values of pork during storage are discussed. The extraction method is an acceptable method for determining TBA values and is easier to use than the distillation method. The TBA test has limited use for meat samples that have been frozen.
EFFECT OF STAPHYLOCOCCUS INFECTION ON ACID AND ALKALINE PHOSPHATASE IN BRUISED POULTRY TISSUE
Authors: HUSSAIN S. S. , HAMDY M. K. 
Published: December 2006

SUMMARYincreasing severity of trauma elicited marked differences in both acid and alkaline phosphatases. The former is a lysosomal enzyme; whereas, the latter is a nonlysosomal enzyme. The magnitude of enzymatic responses as a result of trauma was not the same for each enzyme. Acid phosphatase activity increased in the bruised tissue while alkaline phosphatase activity decreased. The bound form of acid phosphatase increased in the bruised tissue, a form of the enzyme absent in normal tissue. The following factors seem to play an important role on the activities of these enzymes in poultry tissues: age of trauma, severity of the bruise and staphylococcal infection. Rates of changes in the enzymatic activities after infection were directly related to the number of organisms in the infecting dose and induced an alteration in the activities of alkaline phosphatase in the bruised tissue from a decreased to an increased value compared to normal level.
METHOD FOR ISOLATING VIRUSES FROM GROUND BEEF
Authors: SULLIVAN ROBERT , FASSOLITIS ALEXANDER C. , READ RALSTON B. 
Published: December 2006

SUMMARYA method was developed to isolate viruses from ground beef. 5, l‐g samples were taken from each loaf of meat and each sample dispersed in 4 ml of Eagle's minimum essential medium. Elimination or reduction of bacterial and fungal contaminants was accomplished by adding antibiotics to the medium to give final concentrations per ml of 1,000 units of penicillin G, 1,000 μg of streptomycin, 50 μg of tetracycline hydrochloride and 5 μg amphotericin B. The meat slurry was adjusted to pH 8.5 with NaOH, shaken at room temperature (23°C) for 1 hr, pH readjusted to 8.0 and the slurry stored at 4°C for at least 16 hr. After this period, the slurry was reshaken for 1 hr at room temperature, filtered through a double layer of cheese cloth and the filtrate assayed for viruses by a plaque‐forming unit (pfu) procedure. By repeated experiments, this method recovered approximately 75% of input coxsackievirus B‐2. The method was used to examine market‐purchased ground beef for viruses. 1 to 195 viral pfu/5g were isolated from 3 of 12 loaves of meat. 1 loaf yielded poliovirus 1 and echovirus 6, 1 yielded poliovirus 2 and 1 yielded polioviruses 1 and 3.
SOYBEAN FACTORS RELATING TO GAS PRODUCTION BY INTESTINAL BACTERIA
Authors: RACKIS J. J. , SESSA D J. , STEGGERDA F. R. , SHIMIZU T. , ANDERSON J. , PEARL S. L. 
Published: December 2006

SUMMARYAn in vitro assay showed that toasted, dehulled, defatted soybean meal contains a gas‐producing factor and a gas‐inhibiting factor. The oligosaccharides—sucrose, raffinose and stachyose—are associated with the gas‐producing factor when incubated in thioglycollate media with anaerobic bacteria of the intestinal tract of dogs. The phenolic acids in soybeans—syringic and ferulic acid—are effective gas inhibitors in vitro and in intestinal segments of dogs. The lipids, proteins and water‐insoluble polysaccharides of soybean meal have no gas activity. During fermentation, gas production parallels the formation of monosaccharides by enzymatic hydrolysis of raffinose and stachyose. The amount and composition of gas produced from cottonseed and peanut meal were comparable to soybean meal.