bluuebunny/crossref_metadata_2025_split huggingface dataset:
A dehydration‐induced NAC protein, RD26, is involved in a novel ABA‐dependent stress‐signaling pathway
Authors: Fujita Miki , Fujita Yasunari , Maruyama Kyonoshin , Seki Motoaki , Hiratsu Keiichiro , Ohme‐Takagi Masaru , Tran Lam‐Son Phan , Yamaguchi‐Shinozaki Kazuko , Shinozaki Kazuo 
Published: September 2004

Summary Arabidopsis thaliana RD26 cDNA, isolated from dehydrated plants, encodes a NAC protein. Expression of the RD26 gene was induced not only by drought but also by abscisic acid (ABA) and high salinity. The RD26 protein is localized in the nucleus and its C terminal has transcriptional activity. Transgenic plants overexpressing RD26 were highly sensitive to ABA, while RD26‐repressed plants were insensitive. The results of microarray analysis showed that ABA‐ and stress‐inducible genes are upregulated in the RD26‐overexpressed plants and repressed in the RD26‐repressed plants. Furthermore, RD26 activated a promoter of its target gene in Arabidopsis protoplasts. These results indicate that RD26 functions as a transcriptional activator in ABA‐inducible gene expression under abiotic stress in plants.
Adjustment of diurnal starch turnover to short days: depletion of sugar during the night leads to a temporary inhibition of carbohydrate utilization, accumulation of sugars and post‐translational activation of ADP‐glucose pyrophosphorylase in the following light period
Authors: Gibon Yves , Bläsing Oliver E. , Palacios‐Rojas Natalia , Pankovic Dejana , Hendriks Janneke H.M. , Fisahn Joachim , Höhne Melanie , Günther Manuela , Stitt Mark 
Published: September 2004

SummaryA larger proportion of the fixed carbon is retained as starch in the leaf in short days, providing a larger store to support metabolism and carbon export during the long night. The mechanisms that facilitate this adjustment of the sink–source balance are unknown. Starchless pgm mutants were analysed to discover responses that are triggered when diurnal starch turnover is disturbed. Sugars accumulated to high levels during the day, and fell to very low levels by the middle of the night. Sugars rose rapidly in the roots and rosette after illumination, and decreased later in the light period. Global transcript profiling revealed only small differences between pgm and Col0 at the end of the day but large differences at the end of the night, when pgm resembled Col0 after a 4–6 h prolongation of the night and many genes required for biosynthesis and growth were repressed [Plant J. 37 (2004) 914]. It is concluded that transient sugar depletion at the end of the night inhibits carbon utilization at the start of the ensuing light period. A second set of experiments investigated the stimulation of starch synthesis in response to short days in wild‐type Col0. In short days, sugars were very low in the roots and rosette at the end of the dark period, and after illumination accumulated rapidly in both organs to levels that were higher than in long days. The response resembles pgm, except that carbohydrate accumulated in the leaf as starch instead of sugars. A similar response was found after transfer from long to short days. Inclusion of sugar in the rooting medium attenuated the stimulation of starch synthesis. Post‐translational activation of ADP‐glucose pyrophosphorylase (AGPase) was increased in pgm, and in Col0 in short days. It is concluded that starch synthesis is stimulated in short day conditions because sugar depletion at the end of the night triggers a temporary inhibition of growth and carbohydrate utilization in the first part of the light period, leading to transient accumulation of sugar and activation of AGPase.
Purification and cloning of an esterase from the weed black‐grass (Alopecurus myosuroides), which bioactivates aryloxyphenoxypropionate herbicides
Authors: Cummins Ian , Edwards Robert 
Published: September 2004

SummaryCarboxyesterases which activate aryloxyphenoxypropionate (AOPP) graminicides to their bioactive herbicidal acids by hydrolysing the respective ester precursors have been identified in black‐grass (Alopecurus myosuroides), a problem weed of cereal crops in Northern Europe. The dominant 40 kDa carboxyesterase was purified 1700‐fold and identified as a serine hydrolase by affinity labelling with a biotinylated fluorophosphonate suicide substrate. MS–MS sequencing of a peptide digest identified it to be a member of the GDSL family of serine hydrolases. The full‐length A. myosuroides hydrolase (Amgdsh1) was cloned by RACE‐PCR and expressed in the yeast Pichia pastoris as a secreted enzyme. Expression was associated with activity towards AOPP esters. AmGDSH1 was predicted to be glycosylated and exported to the apoplast in planta. Based on the analysis of related sequences in monocotyledonous plants an alternative classification of the GDSL plant hydrolase superfamily is suggested and their importance in endogenous metabolism and herbicide bioactivation in crops and weeds discussed.
Biological functions of ent‐ and syn‐copalyl diphosphate synthases in rice: key enzymes for the branch point of gibberellin and phytoalexin biosynthesis
Authors: Otomo Kazuko , Kenmoku Hiromichi , Oikawa Hideaki , König Wilfried A. , Toshima Hiroaki , Mitsuhashi Wataru , Yamane Hisakazu , Sassa Takeshi , Toyomasu Tomonobu 
Published: September 2004

SummaryRice (Oryza sativa L.) produces ent‐copalyl diphosphate (ent‐CDP) and syn‐CDP as precursors for several classes of phytoalexins and the phytohormones, gibberellins (GAs). It has recently been shown that a loss‐of‐function mutation of OsCPS1, a gene encoding a putative ent‐CDP synthase, results in a severely GA‐deficient dwarf phenotype in rice. To clarify the biological functions of the ent‐ and syn‐CDP synthases involved in the biosynthesis of phytoalexins and/or GAs, we isolated two cDNAs, OsCyc1 and OsCyc2, encoding putative diterpene cyclases from ultraviolet (UV)‐irradiated rice leaves (cv. Nipponbare). The production of phytoalexins in rice leaves is known to be highly induced by UV treatment. Using a bacterial expression system, we demonstrated that OsCyc1 encodes syn‐CDP synthase and that OsCyc2 and OsCPS1 encode ent‐CDP synthase. The level of expression of the OsCyc1 and OsCyc2 transcripts in rice leaves increased drastically in response to UV treatment, whereas expression of the OsCPS1 transcript was not induced by UV light. These results suggest that OsCyc1, OsCyc2 and OsCPS1 are responsible for the biosynthesis of momilactones A and B and oryzalexin S, oryzalexins A–F and phytocassanes A–E, and GAs, respectively. Our results strongly suggest the presence of two ent‐CDP synthase isoforms in rice, one that participates in the biosynthesis of GAs and a second that is involved in the biosynthesis of phytoalexins.
Freezing‐sensitive tomato has a functional CBF cold response pathway, but a CBF regulon that differs from that of freezing‐tolerant Arabidopsis
Authors: Zhang Xin , Fowler Sarah G. , Cheng Hongmei , Lou Yigong , Rhee Seung Y. , Stockinger Eric J. , Thomashow Michael F. 
Published: September 2004

SummaryMany plants increase in freezing tolerance in response to low temperature, a process known as cold acclimation. In Arabidopsis, cold acclimation involves action of the CBF cold response pathway. Key components of the pathway include rapid cold‐induced expression of three homologous genes encoding transcriptional activators, CBF1, 2 and 3 (also known as DREB1b, c and a, respectively), followed by expression of CBF‐targeted genes, the CBF regulon, that increase freezing tolerance. Unlike Arabidopsis, tomato cannot cold acclimate raising the question of whether it has a functional CBF cold response pathway. Here we show that tomato, like Arabidopsis, encodes three CBF homologs, LeCBF1–3 (Lycopersicon esculentum CBF1–3), that are present in tandem array in the genome. Only the tomato LeCBF1 gene, however, was found to be cold‐inducible. As is the case for Arabidopsis CBF1–3, transcripts for LeCBF1–3 did accumulate in response to mechanical agitation, but not in response to drought, ABA or high salinity. Constitutive overexpression of LeCBF1 in transgenic Arabidopsis plants induced expression of CBF‐targeted genes and increased freezing tolerance indicating that LeCBF1 encodes a functional homolog of the Arabidopsis CBF1–3 proteins. However, constitutive overexpression of either LeCBF1 or AtCBF3 in transgenic tomato plants did not increase freezing tolerance. Gene expression studies, including the use of a cDNA microarray representing approximately 8000 tomato genes, identified only four genes that were induced 2.5‐fold or more in the LeCBF1 or AtCBF3 overexpressing plants, three of which were putative members of the tomato CBF regulon as they were also upregulated in response to low temperature. Additional experiments indicated that of eight tomato genes that were likely orthologs of Arabidopsis CBF regulon genes, none were responsive to CBF overexpression in tomato. From these results, we conclude that tomato has a complete CBF cold response pathway, but that the tomato CBF regulon differs from that of Arabidopsis and appears to be considerably smaller and less diverse in function.
Characterization of AtCHX17, a member of the cation/H+ exchangers, CHX family, from Arabidopsis thaliana suggests a role in K+ homeostasis
Authors: Cellier Françoise , Conéjéro Geneviève , Ricaud Lilian , Luu Doan Trung , Lepetit Marc , Gosti Françoise , Casse Francine 
Published: September 2004

SummaryThe Arabidopsis genome contains many sequences annotated as encoding H+‐coupled cotransporters. Among those are the members of the cation:proton antiporter‐2 (CPA2) family (or CHX family), predicted to encode Na+,K+/H+ antiporters. AtCHX17, a member of the CPA2 family, was selected for expression studies, and phenotypic analysis of knockout mutants was performed. AtCHX17 expression was only detected in roots. The gene was strongly induced by salt stress, potassium starvation, abscisic acid (ABA) and external acidic pH. Using the β‐glucuronidase reporter gene strategy and in situ RT‐PCR experiments, we have found that AtCHX17 was expressed preferentially in epidermal and cortical cells of the mature root zones. Knockout mutants accumulated less K+ in roots in response to salt stress and potassium starvation compared with the wild type. These data support the hypothesis that AtCHX17 is involved in K+ acquisition and homeostasis.
Dissecting large and complex genomes: flow sorting and BAC cloning of individual chromosomes from bread wheat
Authors: Šafář Jan , Bartoš Jan , Janda Jaroslav , Bellec Arnaud , Kubaláková Marie , Valárik Miroslav , Pateyron Stéphanie , Weiserová Jitka , Tušková Radka , Číhalíková Jarmila , Vrána Jan , Šimková Hana , Faivre‐Rampant Patricia , Sourdille Pierre , Caboche Michel , Bernard Michel , Doležel Jaroslav , Chalhoub Boulos 
Published: September 2004

SummaryThe analysis of the complex genome of common wheat (Triticum aestivum, 2n = 6x = 42, genome formula AABBDD) is hampered by its large size (∼17 000 Mbp) and allohexaploid nature. In order to simplify its analysis, we developed a generic strategy for dissecting such large and complex genomes into individual chromosomes. Chromosome 3B was successfully sorted by flow cytometry and cloned into a bacterial artificial chromosome (BAC), using only 1.8 million chromosomes and an adapted protocol developed for this purpose. The BAC library (designated as TA‐3B) consists of 67 968 clones with an average insert size of 103 kb. It represents 6.2 equivalents of chromosome 3B with 100% coverage and 90% specificity as confirmed by genetic markers. This method was validated using other chromosomes and its broad application and usefulness in facilitating wheat genome analysis were demonstrated by target characterization of the chromosome 3B structure through cytogenetic mapping. This report on the successful cloning of flow‐sorted chromosomes into BACs marks the integration of flow cytogenetics and genomics and represents a great leap forward in genetics and genomic analysis.
High humidity suppresses ssi4‐mediated cell death and disease resistance upstream of MAP kinase activation, H2O2 production and defense gene expression
Authors: Zhou Fasong , Menke Frank L.H. , Yoshioka Keiko , Moder Wolfgang , Shirano Yumiko , Klessig Daniel F. 
Published: September 2004

SummaryThe Arabidopsis ssi4 mutant, which exhibits spontaneous lesion formation, constitutive expression of pathogenesis‐related (PR) genes and enhanced resistance to virulent bacterial and oomycete pathogens, contains a gain‐of‐function mutation in a TIR‐NBS‐LRR type R gene. Epistatic analyses revealed that both PR gene expression and disease resistance are activated via a salicylic acid (SA)‐ and EDS1‐dependent, but NPR1‐ and NDR1‐independent signaling pathway. In this study, we demonstrate that in moderate relative humidity (RH; 60%), the ssi4 mutant accumulates H2O2 and SA prior to lesion formation and displays constitutive activation of the MAP kinases AtMPK6 and AtMPK3. It also constitutively expresses a variety of defense‐associated genes, including those encoding the WRKY transcription factors AtWRKY29 and AtWRKY6, the MAP kinases AtMPK6 and AtMPK3, the powdery mildew R proteins RPW8.1 and RPW8.2, EDS1 and PR proteins. All of these ssi4‐induced responses, as well as the chlorotic, stunted morphology and enhanced disease resistance phenotype, are suppressed by high RH (95%) growth conditions. Thus, a humidity sensitive factor (HSF) appears to function at an early point in the ssi4 signaling pathway. All ssi4 phenotypes, except for MAP kinase activation, also were suppressed by the eds1‐1 mutation. Thus, ssi4‐induced MAP kinase activation occurs downstream of the HSF but either upstream of EDS1 or on a separate branch of the ssi4 signaling pathway. SA is a critical signaling component in ssi4‐mediated defense responses. However, exogenously supplied SA failed to restore lesion formation in high RH‐grown ssi4 plants, although it induced defense gene expression. Thus, additional signals also are involved.
Optimal timing for living‐related liver transplantation in children
Authors: Kimura Takuya , Hasegawa Toshimichi , Sasaki Takashi , Shimizu Yoshiyuki , Mushiake Sohtarou , Fukuzawa Masahiro , Okada Akira 
Published: September 2004

Abstract:  Background:  The pediatric end stage liver disease (PELD) score has been used widely to prioritize children awaiting cadaveric liver transplantation (LTx). To establish the objective parameter for optimal timing of living‐related LTx (LRLTx), we have assessed our cases using the PELD score.Methods:  From 1997 to 2002, 24 children were evaluated 28 times for the indication of LRLTx. Among them, 15 were for jaundice and nine for growth failure, hepatopulmonary syndrome, and variceal bleeding. Nine of 24 children underwent LRLTx. They were divided into several groups according to their clinical course. The PELD score consisted of age, albumin, total bilirubin, prothrombine time‐international ratio (INR) and growth failure. A cut‐off value was obtained by the highest positive and negative predictive value.Results:  The PELD score in cases whose indication for LRLTx was approved was significantly higher compared with the cases who were not, and a cut‐off value of 4 was obtained. The PELD score in cases who were alive after LRLTx was significantly lower compared with the cases who died after LRLTx or evaluation of the indication, and a cut‐off value of 22 was established.Conclusion:  LRLTx may be considered when the PELD score exceeds 4, and LRLTx may be required immediately when the PELD score exceeds 22.
Non‐resective ablation therapy for hepatocellular carcinoma: effectiveness measured by intention‐to‐treat and dropout from liver transplant waiting list
Authors: Fisher RA , Maluf D , Cotterell AH , Stravitz T , Wolfe L , Luketic V , Sterling R , Shiffman M , Posner M 
Published: September 2004

Abstract:  Background:  Orthotopic liver transplantation (OLT) for patients with small hepatocellular carcinoma (HCC) is widely accepted, and the usefulness of local ablation techniques as a bridge for liver transplantation is still under investigation.Methods:  From December 1997 to February 2003, patients with cirrhosis and T0‐T1‐T2‐T3 stage HCC received multi‐modality ablative therapy (MMT) for the treatment of their HCC and were evaluated for OLT; listed, and transplanted when an allograft became available. MMT included radiofrequency ablation (RFA), and/or Trans‐Arterial Chemo‐Embolization (TACE), and alcohol (EtOH) ablation, followed by Trans‐Arterial Chemo‐Infusion (TACI), with repeated treatments based on follow up hepatic magnetic resonance imaging (MRI) during the waiting period for OLT.Results:  A total of 135 HCC patients were seen at our center within this time frame. The intention‐to‐treat group included 33 (24.4%) patients with T0, T1, T2, T3 HCC and cirrhosis. There were 31 men and two women. The mean age was 53.6 ± 7.2 yr. All patients received MMT with a mean of 2.90 ± 1.5 procedures per patient. Tumor‐node‐metastasis (TNM) stages at time of listing were: T0 in one patient, T1 in nine patients, T2 in 17 patients, and T3 in six patients. Twenty‐eight (85%) patients have received OLT. Five (12.19%) patients were listed and removed (dropout) from the transplant waiting list after waiting 5, 5, 5, 8, and 14 months respectively. The waiting time of the HCC listed group was 9.1 ± 14.8 months with a mean follow up of 32 months. OLT patient survival and cancer‐free survival are 92.9% and 95.24%, respectively; the overall survival of intention‐to‐treat group was 79% at 32 months follow up. Predictors of dropout included an α‐fetoprotein (AFP, >400 ng/mL) and T3 HCC stage.Conclusion:  Aggressive ablation therapy with a short transplant waiting time optimizes the use of OLT for curative intent in selective cirrhotic HCC patients.
Detection of cardiac allograft rejection by real‐time PCR analysis of circulating mononuclear cells
Authors: Schoels M , Dengler TJ , Richter R , Meuer SC , Giese T 
Published: September 2004

Abstract:  Background:  Detection of cardiac allograft rejection is based on the histological examination of endomyocardial biopsies (EMB). We have explored the possibility of whether graft rejection could be detected by characteristic gene expression patterns in peripheral blood mononuclear cells (PBMC) of heart‐transplant recipients.Methods:  The study included 58 blood samples of 44 patients. On the day of EMB, mononuclear cells were isolated from peripheral blood, and gene expression was measured by quantitative real‐time PCR. Thirty‐nine parameters, including cytokine and chemokine genes were analyzed. Gene expression results were correlated with histological assessment of concomitant evaluated EMB according to International Society for Heart and Lung Transplantation (ISHLT) nomenclature.Results:  Gene expression of perforin, CD95 ligand, granzyme B, RANTES, CXCR3, COX2, ENA 78 and TGF‐β1 was significantly different in PBMC of patients with mild to moderate degrees of allograft rejection (≥grade 2) compared with patients exhibiting no or minor forms of rejection (<grade 2). Using discriminance analysis, five parameters were found that allow discrimination of rejection ≥grade 2 vs. <grade 2 with a sensitivity of 84% and a specificity of 82% as assessed by receiver operating characteristic analysis.Conclusion:  Quantitative analysis of gene expression in PBMC may be a valuable tool for non‐invasive diagnosis of allograft rejection and may allow further insight in the biological process of graft rejection.
Immunological profile of patients awaiting a renal transplant
Authors: Díaz Inmaculada , Sánchez Pilar , Alonso Clara , Valdés Francisco 
Published: September 2004

Abstract: Background: A renal transplant is the best possible treatment for patients with terminal renal failure. Advances in the development of techniques of screening of pre‐formed antibodies have contributed to a notable improvement in the results obtained with allogenic transplants.Methods: The aim of the present work is to study the nature, class, isotype and specificity of antibodies detected in patients awaiting renal transplantation at Complejo Hospitalario Universitario Juan Canalejo, as well as their relation with the level of anti‐human leucocyte antigen (HLA) sensitization.Results: In all patient groups, there was a predominance of IgG. The distribution of anti‐HLA antibody class showed that the most frequent pattern corresponded to a mixture of class I and class II antibodies for all groups. The study of specificity of anti‐HLA antibody showed that of the patients with at least one previous transplant, 72% developed specific anti‐HLA antibodies against some of the incompatible antigens of the donor, 12% against HLA antigens not related with the phenotype of the donor and in 16% it was not possible to determine their specificity. Most patients developed antibodies against antigens of locusB, probably because of that the number of incompatibilities contributed by the donors is also greater for locusB.Conclusions: The exhaustive study of sera of patients on a waiting list for transplantation with respect to the nature, isotype, class and specificity of the antibody is important since it is possible that different antibodies can bring about, in the transplant, events that will have different consequences for the survival of the graft.
Long‐term follow‐up of pediatric transplant recipients: mycophenolic acid trough levels are not a good indicator for long‐term graft function
Authors: Pape L , Ehrich JHH , Offner G 
Published: September 2004

Abstract:  Background:  Mycophenolate mofetil (MMF) has the potential of decreasing acute rejection episodes early following renal transplantation. Pharmocokinetic monitoring of mycophenolic acid (MPA) trough levels is performed by many centers. MMF has also proved successful in improving long‐term graft function in patients with chronic allograft nephropathy (CAN). However, no data for long‐term monitoring of MPA in children have yet been published.Methods:  MMF therapy with a dose of 600 mg/m2 twice daily was initiated in 42 children (median age 9.4 yr, range 1.4–15.1) after a median period of 3.8 yr (range 1.0–10.6) post‐transplantation – according to significant increases in serum creatinine. CAN was diagnosed by renal biopsy and the amount of fibrosis was quantified with PicroSiriusRed staining. MMF therapy was combined with ciclosporin A and prednisolone. MPA‐C0‐levels, measured by high‐pressure liquid chromatography, were tested every 3 months. In 12 children a full MPA area under the curve concentration (AUC) was measured. The glomerular filtration rate (GFR) was calculated at the start of MMF therapy and 2 yr later.Results:  After initiation of MMF, the calculated GFR did not decrease further in 22 children and mean GFR remained stable for 2 yr in the whole study group. There was a significant correlation between MPA levels 75 min after administration and the full AUC (r = 0.94, p < 0.001) but no correlation between trough levels and AUC (r = −0.07, p > 0.05). The mean MPA trough level was 2.8 ± 1.3 ng/mL. The intra‐individual coefficient of variation was 2.6 ± 1.4. There was no correlation between mean MPA trough levels and GFR development after 2 yr (r = 0.03, p > 0.05). In children with an MPA level below 1.2 mg/L (n = 5), the mean GFR decline was no different to those with a higher level (p > 0.05).Conclusions:  Drug monitoring of MPA trough levels had no impact on long‐term graft function in kidney recipients. MPA levels taken 75 min after administration showed a high correlation with MPA‐AUC whereas C0‐levels did not correlate. The value of C75 drug measurements for monitoring renal allograft survival will have to be judged in future studies.