bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sentinel Lymph Node Biopsy: A Rational Approach for Staging T2N0 Oral Cancer
Authors: Rigual Nestor , Douglas Wade , Lamonica Dominick , Wiseman Sam , Cheney Richard , Hicks Wesley , Loree Thom 
Published: December 2005

AbstractObjectives/Hypothesis: For oral cancer patients, the presence of neck nodal metastases is the most important disease prognosticator. However, a significant proportion of clinically N0 patients harbor occult microscopic nodal metastasis. Our objective was to determine the feasibility and accuracy of sentinel node biopsy (SNB) in the staging of T2N0 oral carcinoma patients.Study Design: Prospective analysis.Methods: Twenty patients with previously untreated N0 oral cavity squamous cell carcinoma were studied. Each patient had an SNB performed using preoperative technetium sulfur colloid lymphoscintigraphy, intraoperative gamma probe guidance, and intraoperative peritumoral injection of 1% isosulfan blue. All patients underwent neck dissection.The sentinel lymph nodes (SLNs) were sectioned in 2‐ to 3‐mm intervals, formalin fixed, and sectioned at three levels. The non‐SLNs were sectioned in a routine manner for histologic examination.Results: SLNs were identified in all patients (100%) and accurately predicted the pathologic nodal status in 18 of 20 patients (90%). Tumor was found exclusively in the SLNs in six patients (30%). Two patients had positive SLNs at multiple neck levels. Two patients had a negative SLN and a positive non‐SLN (false‐negative findings). Occult nodal metastases were present in 60% of the cohort.Conclusions: SNB is a technically feasible and accurate procedure for staging the neck in oral carcinoma patients. However, SNB accuracy is lower for floor of the mouth lesions. The rate of occult nodal metastases identified in this cohort is higher than previously reported in the literature. These results suggest that SNB warrants further multi‐institutional studies.
Introduction
Authors: Erdélyi Robert 
Published: December 2005

The Sun's magnetic field is responsible for many spectacularly dynamic and intricate phenomena, such as the 11 year solar activity cycle, the hot and tenuous outer atmosphere called the solar corona, and the continuously expanding stream of solar particles known as the solar wind.
Recently, there has been an enormous increase in our understanding of the role of solar magnetism in producing the observed complex atmosphere of the Sun. One such advance has occurred in the detection, by several different high-resolution space instruments on-board the Solar and Heliospheric Observatory and Transition Region and Coronal Explorer satellites, of magnetic waves and oscillations in the solar corona.
The new subjects of solar atmospheric and coronal seismology are undergoing rapid development. The aim of this Scientific Discussion Meeting was to address the progress made through observational, theoretical and numerical studies of wave phenomena in the magnetic solar plasma. Major theoretical and observational advances were reported by a wide range of international scientists and pioneers in this field, followed by lively discussions and poster sessions on the many intriguing questions raised by the new results. Theoretical and observational aspects of magnetohydrodynamic waves and oscillations in general, and how these wave phenomena differ in various regions of the Sun, including sunspots, the transient lower atmosphere and the corona (in magnetic loops, plumes and prominences), were addressed through invited review papers and selected poster presentations. The results of these deliberations are collected together in this volume.
Lectin Receptor Kinases Participate in Protein-Protein Interactions to Mediate Plasma Membrane-Cell Wall Adhesions in Arabidopsis
Authors: Gouget Anne , Senchou Virginie , Govers Francine , Sanson Arnaud , Barre Annick , Rougé Pierre , Pont-Lezica Rafael , Canut Hervé 
Published: December 2005

Abstract
Interactions between plant cell walls and plasma membranes are essential for cells to function properly, but the molecules that mediate the structural continuity between wall and membrane are unknown. Some of these interactions, which are visualized upon tissue plasmolysis in Arabidopsis (Arabidopsis thaliana), are disrupted by the RGD (arginine-glycine-aspartic acid) tripeptide sequence, a characteristic cell adhesion motif in mammals. In planta induced-O (IPI-O) is an RGD-containing protein from the plant pathogen Phytophthora infestans that can disrupt cell wall-plasma membrane adhesions through its RGD motif. To identify peptide sequences that specifically bind the RGD motif of the IPI-O protein and potentially play a role in receptor recognition, we screened a heptamer peptide library displayed in a filamentous phage and selected two peptides acting as inhibitors of the plasma membrane RGD-binding activity of Arabidopsis. Moreover, the two peptides also disrupted cell wall-plasma membrane adhesions. Sequence comparison of the RGD-binding peptides with the Arabidopsis proteome revealed 12 proteins containing amino acid sequences in their extracellular domains common with the two RGD-binding peptides. Eight belong to the receptor-like kinase family, four of which have a lectin-like extracellular domain. The lectin domain of one of these, At5g60300, recognized the RGD motif both in peptides and proteins. These results imply that lectin receptor kinases are involved in protein-protein interactions with RGD-containing proteins as potential ligands, and play a structural and signaling role at the plant cell surfaces.
Organ-Specific Expression of Glutathione S-Transferases and the Efficacy of Herbicide Safeners in Arabidopsis
Authors: DeRidder Ben P. , Goldsbrough Peter B. 
Published: December 2005

Abstract
The functions of plant glutathione S-transferases (GSTs) under normal growth conditions are poorly understood, but their activity as detoxification enzymes has been harnessed in agriculture for selective weed control. Herbicide safeners protect monocot crops from herbicide injury but have little effect on weedy monocot or dicot species. Protection by safeners is associated with expression of herbicide-metabolizing enzymes including GSTs, but the basis for selective action of safeners between monocots and dicots is not known. To address this question we have studied the response of Arabidopsis (Arabidopsis thaliana) to various safeners. Benoxacor, fenclorim, and fluxofenim did not protect Arabidopsis from herbicide injury but did induce RNA expression of the glutathione-conjugate transporters encoded by AtMRP1, AtMRP2, AtMRP3, and AtMRP4. These safeners also induced the organ-specific expression of AtGSTU19 and AtGSTF2, two previously characterized Arabidopsis GSTs from different classes of this enzyme family. RNA hybridization, immunoblot, and reporter gene analyses indicated expression of AtGSTU19 induced by safeners predominated in roots. To test the hypothesis that increased expression of AtGSTU19 would be sufficient to provide tolerance to chloroacetamide herbicides, a chimeric gene was produced containing the open reading frame for this GST driven by a constitutive promoter. Plants containing this transgene had a modest increase in AtGSTU19 protein, predominantly in roots, but this had no effect on tolerance to chloroacetamide herbicides. The localized induction of GSTs by safeners in roots of Arabidopsis may explain why these compounds are unable to provide herbicide tolerance to dicot plant species.
Identification of a Glyphosate-Resistant Mutant of Rice 5-Enolpyruvylshikimate 3-Phosphate Synthase Using a Directed Evolution Strategy
Authors: Zhou Min , Xu Honglin , Wei Xiaoli , Ye Zhiqiang , Wei Liping , Gong Weimin , Wang Yongqin , Zhu Zhen 
Published: December 2005

Abstract
5-Enolpyruvylshikimate 3-phosphate synthase (EPSPS) is a key enzyme in the shikimate pathway and is targeted by the wide-spectrum herbicide glyphosate. Here, we describe the use of a selection system based on directed evolution to select glyphosate-resistant mutants of EPSPS. Using this system, the rice (Oryza sativa) EPSPS gene, mutagenized by Error-Prone polymerase chain reaction, was introduced into an EPSPS-deficient Escherichia coli strain, AB2829, and transformants were selected on minimal medium by functional complementation. Three mutants with high glyphosate resistance were identified in three independent glyphosate selection experiments. Each mutant contained a C317→T transition within the EPSPS coding sequence, causing a change of proline-106 to leucine (P106L) in the protein sequence. Glyphosate resistance assays indicated a 3-fold increase in glyphosate resistance of E. coli expressing the P106L mutant. Affinity of the P106L mutant for glyphosate and phosphoenolpyruvate was decreased about 70-fold and 4.6-fold, respectively, compared to wild-type EPSPS. Analysis based on a kinetic model demonstrates that the P106L mutant has a high glyphosate resistance while retaining relatively high catalytic efficiency at low phosphoenolpyruvate concentrations. A mathematical model derived from the Michaelis-Menten equation was used to characterize the effect of expression level and selection conditions on kinetic (Ki and Km) variation of the mutants. This prediction suggests that the expression level is an important aspect of the selection system. Furthermore, glyphosate resistance of the P106L mutant was confirmed in transgenic tobacco (Nicotiana tabacum), demonstrating the potential for using the P106L mutant in transgenic crops.
A Circadian Rhythm-Regulated Tomato Gene Is Induced by Arachidonic Acid and Phythophthora infestans Infection
Authors: Weyman Philip D. , Pan Zhiqiang , Feng Qin , Gilchrist David G. , Bostock Richard M. 
Published: December 2005

Abstract
A cDNA clone of unknown function, DEA1, was isolated from arachidonic acid-treated tomato (Solanum lycopersicum) leaves by differential display PCR. The gene, DEA1, is expressed in response to the programmed cell death-inducing arachidonic acid within 8 h following treatment of a tomato leaflet, 16 h prior to the development of visible cell death. DEA1 transcript levels were also affected by the late blight pathogen ,Phytophthora infestans. To gain further insight into the transcriptional regulation of DEA1, the promoter region was cloned by inverse PCR and was found to contain putative stress-, signaling-, and circadian-response elements. DEA1 is highly expressed in roots, stems, and leaves, but not in flowers. Leaf expression of DEA1 is regulated by circadian rhythms during long days with the peak occurring at midday and the low point midway through the dark period. During short days, the rhythm is lost and DEA1 expression becomes constitutive. The predicted DEA1 protein has a conserved domain shared by the eight-cysteine motif superfamily of protease inhibitors, α-amylase inhibitors, seed storage proteins, and lipid transfer proteins. A DEA1-green fluorescent protein fusion protein localized to the plasma membrane in protoplasts and plasmolysis experiments, suggesting that the native protein is associated with the plasmalemma in intact cells.
Increased Accumulation of Cuticular Wax and Expression of Lipid Transfer Protein in Response to Periodic Drying Events in Leaves of Tree Tobacco
Authors: Cameron Kimberly D. , Teece Mark A. , Smart Lawrence B. 
Published: December 2005

Abstract
Cuticular wax deposition and composition affects drought tolerance and yield in plants. We examined the relationship between wax and dehydration stress by characterizing the leaf cuticular wax of tree tobacco (Nicotiana glauca L. Graham) grown under periodic dehydration stress. Total leaf cuticular wax load increased after each of three periods of dehydration stress using a CH2Cl2 extraction process. Overall, total wax load increased 1.5- to 2.5-fold, but composition of the wax was not altered. Homologous series of wax components were classified into organic groups; n-hentriacontane was the largest component (&gt;75%) with alcohols and fatty acids representing &lt;10% of the entire wax load. An increase in density, but no change in the three-dimensional shape, of leaf wax crystals was evident under low-kV scanning electron microscopy after each drying event. Leaves excised from plants subjected to multiple drying events were more resistant to water loss compared to leaves excised from well-watered plants, indicating that there is a negative relationship between total wax load and epidermal conductance. Lipid transfer proteins (LTPs) are thought to be involved in the transfer of lipids through the extracellular matrix for the formation of cuticular wax. Using northern analysis, a 6-fold increase of tree tobacco LTP gene transcripts was observed after three drying events, providing further evidence that LTP is involved in cuticle deposition. The simplicity of wax composition and the dramatic wax bloom displayed by tree tobacco make this an excellent species in which to study the relationship between leaf wax deposition and drought tolerance.
The Regulator of G-Protein Signaling Proteins Involved in Sugar and Abscisic Acid Signaling in Arabidopsis Seed Germination
Authors: Chen Yun , Ji Fangfang , Xie Hong , Liang Jiansheng , Zhang Jianhua 
Published: December 2005

AbstractThe regulator of G-protein signaling (RGS) proteins, recently identified in Arabidopsis (Arabidopsis thaliana; named as AtRGS1), has a predicted seven-transmembrane structure as well as an RGS box with GTPase-accelerating activity and thus desensitizes the G-protein-mediated signaling. The roles of AtRGS1 proteins in Arabidopsis seed germination and their possible interactions with sugars and abscisic acid (ABA) were investigated in this study. Using seeds that carry a null mutation in the genes encoding RGS protein (AtRGS1) and the α-subunit (AtGPA1) of the G protein in Arabidopsis (named rgs1-2 and gpa1-3, respectively), our genetic evidence proved the involvement of the AtRGS1 protein in the modulation of seed germination. In contrast to wild-type Columbia-0 and gpa1-3, stratification was found not to be required and the after-ripening process had no effect on the rgs1-2 seed germination. In addition, rgs1-2 seed germination was insensitive to glucose (Glc) and sucrose. The insensitivities of rgs1-2 to Glc and sucrose were not due to a possible osmotic stress because the germination of rgs1-2 mutant seeds showed the same response as those of gpa1-3 mutants and wild type when treated with the same concentrations of mannitol and sorbitol. The gpa1-3 seed germination was hypersensitive while rgs1-2 was less sensitive to exogenous ABA. The different responses to ABA largely diminished and the inhibitory effects on seed germination by exogenous ABA and Glc were markedly alleviated when endogenous ABA biosynthesis was inhibited. Hypersensitive responses of seed germination to both Glc and ABA were also observed in the overexpressor of AtRGS1. Analysis of the active endogenous ABA levels and the expression of NCED3 and ABA2 genes showed that Glc significantly stimulated the ABA biosynthesis and increased the expression of NCED3 and ABA2 genes in germinating Columbia seeds, but not in rgs1-2 mutant seeds. These data suggest that AtRGS1 proteins are involved in the regulation of seed germination. The hyposensitivity of rgs1-2 mutant seed germination to Glc might be the result of the impairment of ABA biosynthesis during seed germination.
The Protein Phosphatase AtPP2CA Negatively Regulates Abscisic Acid Signal Transduction in Arabidopsis, and Effects of abh1 on AtPP2CA mRNA
Authors: Kuhn Josef M. , Boisson-Dernier Aurélien , Dizon Marie B. , Maktabi Mohammad H. , Schroeder Julian I. 
Published: December 2005

Abstract
To identify new loci in abscisic acid (ABA) signaling, we screened a library of 35S∷cDNA Arabidopsis (Arabidopsis thaliana)-expressing lines for ABA-insensitive mutants in seed germination assays. One of the identified mutants germinated on 2.5 μ m ABA, a concentration that completely inhibits wild-type seed germination. Backcrosses and F2 analyses indicated that the mutant exhibits a dominant phenotype and that the ABA insensitivity was linked to a single T-DNA insertion containing a 35S∷cDNA fusion. The inserted cDNA corresponds to a full-length cDNA of the AtPP2CA gene, encoding a protein phosphatase type 2C (PP2C). Northern-blot analyses demonstrated that the AtPP2CA transcript is indeed overexpressed in the mutant (named PP2CAox). Two independent homozygous T-DNA insertion lines, pp2ca-1 and pp2ca-2, were recovered from the Arabidopsis Biological Resource Center and shown to lack full-length AtPP2CA expression. A detailed characterization of PP2CAox and the T-DNA disruption mutants demonstrated that, whereas ectopic expression of a 35S∷AtPP2CA fusion caused ABA insensitivity in seed germination and ABA-induced stomatal closure responses, disruption mutants displayed the opposite phenotype, namely, strong ABA hypersensitivity. Thus our data demonstrate that the PP2CA protein phosphatase is a strong negative regulator of ABA signal transduction. Furthermore, it has been previously shown that the AtPP2CA transcript is down-regulated in the ABA-hypersensitive nuclear mRNA cap-binding protein mutant abh1. We show here that down-regulation of AtPP2CA in abh1 is not due to impaired RNA splicing of AtPP2CA pre-mRNA. Moreover, expression of a 35S∷AtPP2CA cDNA fusion in abh1 partially suppresses abh1 hypersensitivity, and the data further suggest that additional mechanisms contribute to ABA hypersensitivity of abh1.
Grapes on Steroids. Brassinosteroids Are Involved in Grape Berry Ripening
Authors: Symons Gregory M. , Davies Christopher , Shavrukov Yuri , Dry Ian B. , Reid James B. , Thomas Mark R. 
Published: December 2005

Abstract
Fruit ripening is a unique plant developmental process with direct implications for our food supply, nutrition, and health. In contrast to climacteric fruit, where ethylene is pivotal, the hormonal control of ripening in nonclimacteric fruit, such as grape (Vitis vinifera), is poorly understood. Brassinosteroids (BRs) are steroidal hormones, essential for normal plant growth and development but not previously implicated in the ripening of nonclimacteric fruit. Here we show that increases in endogenous BR levels, but not indole-3-acetic acid (IAA) or GA levels, are associated with ripening in grapes. Putative grape homologs of genes encoding BR biosynthesis enzymes (BRASSINOSTEROID-6-OXIDASE and DWARF1) and the BR receptor (BRASSINOSTEROID INSENSITIVE 1) were isolated, and the function of the grape BRASSINOSTEROID-6-OXIDASE gene was confirmed by transgenic complementation of the tomato (Lycopersicon esculentum) extreme dwarf (dx/dx) mutant. Expression analysis of these genes during berry development revealed transcript accumulation patterns that were consistent with a dramatic increase in endogenous BR levels observed at the onset of fruit ripening. Furthermore, we show that application of BRs to grape berries significantly promoted ripening, while brassinazole, an inhibitor of BR biosynthesis, significantly delayed fruit ripening. These results provide evidence that changes in endogenous BR levels influence this key developmental process. This may provide a significant insight into the mechanism controlling ripening in grapes, which has direct implications for the logistics of grape production and down-stream processing.
Role of Petal-Specific Orcinol O-Methyltransferases in the Evolution of Rose Scent
Authors: Scalliet Gabriel , Lionnet Claire , Le Bechec Mickaël , Dutron Laurence , Magnard Jean-Louis , Baudino Sylvie , Bergougnoux Véronique , Jullien Frédéric , Chambrier Pierre , Vergne Philippe , Dumas Christian , Cock J. Mark , Hugueney Philippe 
Published: December 2005

Abstract
Orcinol O-methyltransferase (OOMT) 1 and 2 catalyze the last two steps of the biosynthetic pathway leading to the phenolic methyl ether 3,5-dimethoxytoluene (DMT), the major scent compound of many rose (Rosa x hybrida) varieties. Modern roses are descended from both European and Chinese species, the latter being producers of phenolic methyl ethers but not the former. Here we investigated why phenolic methyl ether production occurs in some but not all rose varieties. In DMT-producing varieties, OOMTs were shown to be localized specifically in the petal, predominanty in the adaxial epidermal cells. In these cells, OOMTs become increasingly associated with membranes during petal development, suggesting that the scent biosynthesis pathway catalyzed by these enzymes may be directly linked to the cells' secretory machinery. OOMT gene sequences were detected in two non-DMT-producing rose species of European origin, but no mRNA transcripts were detected, and these varieties lacked both OOMT protein and enzyme activity. These data indicate that up-regulation of OOMT gene expression may have been a critical step in the evolution of scent production in roses.
Cell Type-Specific Role of the Retinoblastoma/E2F Pathway during Arabidopsis Leaf Development
Authors: Desvoyes Bénédicte , Ramirez-Parra Elena , Xie Qi , Chua Nam-Hai , Gutierrez Crisanto 
Published: December 2005

Abstract
Organogenesis in plants is almost entirely a postembryonic process. This unique feature implies a strict coupling of cell proliferation and differentiation, including cell division, arrest, cell cycle reactivation, endoreplication, and differentiation. The plant retinoblastoma-related (RBR) protein modulates the activity of E2F transcription factors to restrict cell proliferation. Arabidopsis contains a single RBR gene, and its loss of function precludes gamete formation and early development. To determine the relevance of the RBR/E2F pathway during organogenesis, outside its involvement in cell division, we have used an inducible system to inactivate RBR function and release E2F activity. Here, we have focused on leaves where cell proliferation and differentiation are temporally and developmentally regulated. Our results reveal that RBR restricts cell division early during leaf development when cell proliferation predominates, while it regulates endocycle occurrence at later stages. Moreover, shortly after leaving the cell cycle, most of leaf epidermal pavement cells retain the ability to reenter the cell cycle and proliferate, but maintain epidermal cell fate. On the contrary, mesophyll cells in the inner layers do not respond in this way to RBR loss of activity. We conclude that there exists a distinct response of different cells to RBR inactivation in terms of maintaining the balance between cell division and endoreplication during Arabidopsis (Arabidopsis thaliana) leaf development.