bluuebunny/crossref_metadata_2025_split huggingface dataset:
HYPERSENSITIVE TO RED AND BLUE 1 and its C‐terminal regulatory function control FLOWERING LOCUS T expression
Authors: Kang Xiaojun , Zhou Yun , Sun Xiaodong , Ni Min 
Published: October 2007

SummaryThe red and far‐red light‐absorbing phytochromes and UV‐A/blue light‐absorbing cryptochromes regulate seedling de‐etiolation and flowering responses. The signaling steps that mediate the photoreceptor regulation on key flowering genes remain largely unknown. We report that a previously identified photomorphogenic mutant, hypersensitive to red and blue 1 (hrb1), flowered late and showed attenuated expression of FLOWERING LOCUS T (FT) over both long days and short days. Transgenic plants that overexpress the full‐length HRB1, or its C‐terminal half, flowered early and accumulated more FT messages under short‐day conditions. The transgenic plants also displayed hyposensitive de‐etiolation phenotypes, and the expression of these phenotypes requires the action of PIF4. The double mutant of hrb1/cry2 showed a flowering phenotype and an FT expression pattern similar to hrb1 under long‐day conditions, suggesting that HRB1 may function downstream of cry2 under long‐day conditions. In contrast, hrb1/phyB‐9 showed a flowering phenotype and an FT expression pattern similar to phyB‐9 over both long days and short days, indicating a modulatory role of HRB1 in the flowering pathway mediated by phyB. Overexpression of HRB1 did not affect the expression of the central clock oscillators, TOC1 and CCA1. HRB1 therefore represents a signaling step that regulates FT expression downstream of red and blue light perception.
Potassium transport systems in the moss Physcomitrella patens: pphak1 plants reveal the complexity of potassium uptake
Authors: Garciadeblas Blanca , Barrero‐Gil Javier , Benito Begoña , Rodríguez‐Navarro Alonso 
Published: October 2007

SummaryPotassium uptake is one of the most basic processes of plant physiology. However, a comprehensive description is lacking. At a cellular level fungi have provided a helpful but imperfect plant model, which we aim to improve using Physcomitrella patens. Blast searches in expressed sequence tag databases demonstrated that Physcomitrella expresses the same families of K+ and Na+ transport systems as flowering plants. We cloned two inward rectifier channels, PpAKT1‐2, and four HAK‐type transporters (PpHAK1‐4). In both types of transport system, phylogenetic analyses revealed that despite their high sequence conservation they could not be included in Arabidopsis or rice (Oryza sativa) clusters. Both inward rectifier channels and one HAK transporter (PpHAK1) were expressed in yeast. PpAKT1 and activated mutants of PpAKT2 and PpHAK1 showed clear functions that were similar to those of homologous systems of flowering plants. A pphak1 null mutant line of Physcomitrella failed to deplete K+ below 10 μm. Moreover, in a non‐K+‐limiting medium in which wild‐type plants grew only as protonema, pphak1‐1 plants produced leafy gametophores and contained 60% more K+. We found that Physcomitrella takes up K+ through several systems. PpHAK1 is the dominant system in plants that underwent K+ starvation for long periods but an as‐yet unidentified system, which is non‐selective for K+, Rb+, and Cs+, dominates in many other conditions. Finally, we discuss that, similar to PpHAK1, one of the functions of AtHAK5 may be to control cellular K+ content and that a non‐selective as‐yet unidentified system also exists in Arabidopsis.
Absence of the endo‐β‐1,4‐glucanases Cel1 and Cel2 reduces susceptibility to Botrytis cinerea in tomato
Authors: Flors Víctor , Leyva María de la O. , Vicedo Begonya , Finiti Ivan , Real María Dolores , García‐Agustín Pilar , Bennett Alan B. , González‐Bosch Carmen 
Published: October 2007

SummaryCel1 and Cel2 are members of the tomato (Solanum lycopersicum Mill) endo‐β‐1,4‐glucanase (EGase) family that may play a role in fruit ripening and organ abscission. This work demonstrates that Cel1 protein is present in other vegetative tissues and accumulates during leaf development. We recently reported the downregulation of both the Cel1 mRNA and protein upon fungal infection, suggesting the involvement of EGases in plant–pathogen interactions. This hypothesis was confirmed by assessing the resistance to Botrytis cinerea infection of transgenic plants expressing both genes in an antisense orientation (Anti‐Cel1, Anti‐Cel2 and Anti‐Cel1‐Cel2). The Anti‐Cel1‐Cel2 plants showed enhanced resistance to this fungal necrotroph. Microscopical analysis of infected leaves revealed that tomato plants accumulated pathogen‐inducible callose within the expanding lesion. Anti‐Cel1‐Cel2 plants presented a faster and enhanced callose accumulation against B. cinerea than wild‐type plants. The inhibitor 2‐deoxy‐d‐glucose, a callose synthesis inhibitor, showed a direct relationship between faster callose accumulation and enhanced resistance to B. cinerea. EGase activity appears to negatively modulate callose deposition. The absence of both EGase genes was associated with changes in the expression of the pathogen‐related genes PR1 and LoxD. Interestingly, Anti‐Cel1‐Cel2 plants were more susceptible to Pseudomonas syringae, displaying severe disease symptoms and enhanced bacterial growth relative to wild‐type plants. Analysis of the involvement of Cel1 and Cel2 in the susceptibility to B. cinerea in fruits was done with the ripening‐impaired mutants Never ripe (Nr) and Ripening inhibitor (rin). The data reported in this work support the idea that enzymes involved in cell wall metabolism play a role in susceptibility to pathogens.
Regulatory interaction of the Gα protein with phospholipase A2 in the plasma membrane of Eschscholzia californica
Authors: Heinze Michael , Steighardt Jörg , Gesell Andreas , Schwartze Wieland , Roos Werner 
Published: October 2007

SummaryPlant heterotrimeric G‐proteins are involved in a variety of signaling pathways, though only one α and a few βγ isoforms of their subunits exist. In isolated plasma membranes of California poppy (Eschscholzia californica), the plant‐specific Gα subunit was isolated and identified immunologically and by homology of the cloned gene with that of several plants. In the same membrane, phospholipase A2 (PLA2) was activated by yeast elicitor only if GTPγS (an activator of Gα) was present. From the cholate‐solubilized membrane proteins, PLA2 was co‐precipitated together with Gα by a polyclonal antiserum raised against the recombinant Gα. In this immunoprecipitate and in the plasma membrane (but not in the Gα‐free supernatant) PLA2 was stimulated by GTPγS. Plasma membranes and immunoprecipitates obtained from antisense transformants with a low Gα content allowed no such stimulation. An antiserum raised against the C‐terminus (which in animal Gαs is located near the target coupling site) precipitated Gα without any PLA2 activity. Using non‐denaturing PAGE, complexes of solubilized plasma membrane proteins were visualized that contained Gα plus PLA2 activity and dissociated at pH 9.5. At this pH, PLA2 was no longer stimulated by GTPγS. It is concluded that a distinct fraction of the plasma membrane‐bound PLA2 exists in a detergent‐resistant complex with Gα that can be dissociated at pH 9.5. This complex allows the Gα‐mediated activation of PLA2.
Seed after‐ripening is a discrete developmental pathway associated with specific gene networks in Arabidopsis
Authors: Carrera Esther , Holman Tara , Medhurst Anne , Dietrich Daniela , Footitt Steven , Theodoulou Frederica L. , Holdsworth Michael J. 
Published: October 2007

SummaryAfter‐ripening (AR) is a time and environment regulated process occurring in the dry seed, which determines the germination potential of seeds. Both metabolism and perception of the phytohormone abscisic acid (ABA) are important in the initiation and maintenance of dormancy. However, molecular mechanisms that regulate the capacity for dormancy or germination through AR are unknown. To understand the relationship between ABA and AR, we analysed genome expression in Arabidopsis thaliana mutants defective in seed ABA synthesis (aba1‐1) or perception (abi1‐1). Even though imbibed mutant seeds showed no dormancy, they exhibited changes in global gene expression resulting from dry AR that were comparable with changes occurring in wild‐type (WT) seeds. Core gene sets were identified that were positively or negatively regulated by dry seed storage. Each set included a gene encoding repression or activation of ABA function (LPP2 and ABA1, respectively), thereby suggesting a mechanism through which dry AR may modulate subsequent germination potential in WT seeds. Application of exogenous ABA to after‐ripened WT seeds did not reimpose characteristics of freshly harvested seeds on imbibed seed gene expression patterns. It was shown that secondary dormancy states reinstate AR status‐specific gene expression patterns. A model is presented that separates the action of ABA in seed dormancy from AR and dry storage regulated gene expression. These results have major implications for the study of genetic mechanisms altered in seeds as a result of crop domestication into agriculture, and for seed behaviour during dormancy cycling in natural ecosystems.
A cascade of transcription factor DREB2A and heat stress transcription factor HsfA3 regulates the heat stress response of Arabidopsis
Authors: Schramm Franziska , Larkindale Jane , Kiehlmann Elke , Ganguli Arnab , Englich Gisela , Vierling Elizabeth , Von Koskull‐Döring Pascal 
Published: October 2007

SummaryThe dehydration‐responsive element binding protein (DREB)/C‐repeat binding factor (CBF) family are the classical transcriptional regulators involved in plant responses to drought, salt and cold stress. Recently it was demonstrated that DREB2A is induced by heat stress (hs) and is a regulator of the hs response of Arabidopsis. Here we provide molecular insights into the regulation and function of hs transcription factor HsfA3. Among the 21 members of the Arabidopsis Hsf family, HsfA3 is the only Hsf that is transcriptionally induced during hs by DREB2A, and HsfA3 in turn regulates the expression of Hsp‐encoding genes. This transcription factor cascade was reconstructed in transient GUS reporter assays in mesophyll protoplasts by showing that DREB2A could activate the HsfA3 promoter, whereas HsfA3 in turn was shown to be a potent activator on the promoters of Hsp genes. Direct binding to the corresponding promoters was demonstrated by electrophoretic mobility shift assays, and the involvement of HsfA3 in the hs response in vivo was shown directly by observation of reduced thermotolerance in HsfA3 mutant lines. Altogether these data demonstrate that HsfA3 is transcriptionally controlled by DREB2A and important for the establishment of thermotolerance.
Arabidopsis extra‐large G proteins (XLGs) regulate root morphogenesis
Authors: Ding Lei , Pandey Sona , Assmann Sarah M. 
Published: October 2007

SummaryAs in mammalian systems, heterotrimeric G proteins, composed of α, β and γ subunits, are present in plants and are involved in the regulation of development and cell signaling. Besides the sole prototypical G protein α subunit gene, GPA1, the Arabidopsis thaliana genome has three extra‐large GTP‐binding protein (XLG)‐encoding genes: XLG1 (At2g23460), XLG2 (At4g34390) and XLG3 (At1g31930). The C‐termini of the XLGs are Gα domains that are homologous to GPA1, whereas their N‐termini each contain a cysteine‐rich region and a putative nuclear localization signal (NLS). GFP fusions with each XLG confirmed nuclear localization. All three XLG genes are expressed in essentially all plant organs, with strong expression in vascular tissues, primary root meristems and lateral root primordia. Analysis of single, double and triple T‐DNA insertional mutants of the XLG genes revealed redundancy in XLG function. Dark‐grown xlg1‐1 xlg2‐1 xlg3‐1 triple mutant plants showed markedly increased primary root length compared with wild‐type plants. This phenotype was not observed in dark‐grown xlg single mutants, and was suppressed upon complementation of the xlg triple mutant with each XLG. Root cell sizes of the xlg triple mutant and root morphology were highly similar to those of wild‐type roots, suggesting that XLGs may regulate cell proliferation. Dark‐grown roots of the xlg triple mutants also showed altered sensitivity to sugars, ABA hyposensitivity and ethylene hypersensitivity, whereas seed germination in xlg triple mutants was hypersensitive to osmotic stress and ABA. As plant‐specific proteins, regulatory mechanisms of XLGs may differ from those of conventional Gαs.
Arabidopsis endo‐1,4‐β‐glucanases are involved in the formation of root syncytia induced by Heterodera schachtii
Authors: Wieczorek Krzysztof , Hofmann Julia , Blöchl Andreas , Szakasits Dagmar , Bohlmann Holger , Grundler Florian M. W. 
Published: October 2007

SummaryCyst nematodes induce root syncytia with specific features such as hypertrophy, increased metabolic activity and fusion with adjacent cells. Cell walls of the syncytia undergo massive changes such as thickening, local dissolution and formation of ingrowths. Cell wall degrading and modifying proteins are apparently involved in syncytium formation but detailed knowledge of this is still limited. Therefore, we studied the regulation and function of the entire Arabidopsis endo‐1,4‐β‐glucanase gene family in syncytia induced by Heterodera schachtii. Endo‐1,4‐β‐glucanases hydrolyze the 1,4‐β‐glucosidic linkages between glucose residues. Using semi‐quantitative and quantitative approaches we identified seven genes that are upregulated in syncytia. Two of these genes, coding for secreted AtCel2 and membrane‐bound KOR3, are shoot‐specific but show high expression in syncytia at different developmental stages. In silico analysis of the promoter regions of both genes compared with other genes with modified regulation in nematode feeding sites did not reveal specific cis‐acting elements that could be related to specific transcription in syncytia. However, motifs responsive to sugar and different plant hormones were identified. Accordingly, treatments with sucrose, gibberellic acid and NAA induced upregulation of AtCel2, whereas ABA triggered downregulation of both AtCel2 and KOR3 in roots. As AtCel2 is related to degradation of the cell wall matrix, we analysed the hemicellulose content in syncytia. The measured values resembled the expression pattern of AtCel2. A distinctly reduced number of females developed in cel2 and kor3 T‐DNA mutants, and we therefore conclude that endo‐1,4‐β‐glucanases play an important role in the formation and function of syncytia.
Staging of necrotizing fasciitis based on the evolving cutaneous features
Authors: Wang Yi‐Shi , Wong Chin‐Ho , Tay Yong‐Kwang 
Published: October 2007

AbstractBackground  Necrotizing fasciitis is a severe soft‐tissue infection characterized by a fulminant course and high mortality. Early recognition is difficult as the disease is often clinically indistinguishable from cellulitis and other soft‐tissue infections early in its evolution. Our aim was to study the manifestations of the cutaneous signs of necrotizing fasciitis as the disease evolves.Methods  This was a retrospective study on patients with necrotizing fasciitis at a single institution. Their charts were reviewed to document the daily cutaneous changes from the time of presentation (day 0) through to day 4 from presentation.Results  Twenty‐two patients were identified. At initial assessment (day 0), almost all patients presented with erythema, tenderness, warm skin, and swelling. Blistering occurred in 41% of patients at presentation whereas late signs such as skin crepitus, necrosis, and anesthesia were infrequently seen (0–5%). As time elapsed, more patients had blistering (77% had blisters at day 4) and eventually the late signs of necrotizing fasciitis characterized by skin crepitus, necrosis, and anesthesia (9–36%) were seen. A clinical staging system was developed based on our observations. Stage migration from early to late stage necrotizing fasciitis was evident with majority of patients in stage 1 at day 0 (59%), whereas by day 4, majority had developed into stage 3 (68%).Conclusion  This study has demonstrated the continuum of cutaneous manifestations as necrotizing fasciitis evolves. This will help in the early recognition and intervention of this devastating condition.
Skin findings in internal malignant diseases
Authors: Kılıç Arzu , Gül Ülker , Soylu Seçil 
Published: October 2007

AbstractPurpose  A skin finding may be an indicator of internal malignant diseases. In this report, we investigated the skin findings of the cases who have had internal malignancy within the last 1 month.Patients and methods  Seven hundred cases who were diagnosed as internal malignancy and who did not have any treatment for the malignancy were enrolled in our study between February 2002 and September 2003. A form was completed for all of the cases, including name, surname, and the carcinoma type. All cases were examined in detail, and the observed skin findings or dermatosis was recorded.Results  The most frequent skin findings among the cases were tinea pedis/onychomycosis, followed by xerosis and pruritus. The skin findings in terms of frequency were determined mostly in hematological malignancies (68.96%).Conclusion  We would like to emphasize that the skin is an indicator of the functions of internal organs and their disorders.
Peptide Fraction Inhibiting Plant Pathogen Growth Predominated in Cell Wall Extracts from Young Plants or in Soluble Cell Fraction from Expanded leaves from Eggplants
Authors: Almeida H. O. , Mattos E. C. , Barbosa M. O. , Teixeira F. R. , Magalhães R. D. M. , Romeiro R. S. , Fontes E. P. B. , Baracat‐Pereira M. C. 
Published: October 2007

AbstractSome varieties of eggplant are little susceptible to some plant pathogens, and antimicrobial peptides (AMPs) could be part of this innate‐defence mechanism. This work aimed to evaluate the in vitro antimicrobial activity of peptide‐enriched fractions from cell wall extracts (CWE) and soluble extracts (SE) from young plants and fully expanded leaves of eggplants against Ralstonia solanacearum and Clavibacter michiganensis ssp. michiganensis growth. The results indicated that the highest inhibition level of the multiplication of both bacteria was obtained with CWE from 5‐cm‐height plants, while SE promoted the highest inhibition rate when 15‐cm‐height plants or fully expanded leaves were analysed. These results suggest that young plants exhibit an innate‐defence mechanism, very likely involving cell wall AMPs action to minimize plant antimicrobial invasion, while expanded leaves could produce soluble defence molecules. The inhibition rate was dependent for the extract concentration and the extracts were more effective against the growth of Gram‐negative bacteria.
Microbial Fungicides in the Control of Plant Diseases
Authors: Kim Beom Seok , Hwang Byung Kook 
Published: October 2007

AbstractAs environmental and commercial requirements for new fungicides are increasingly demanding, antifungal compounds of microbial origin attract tremendous interest as a starting point in the development of environmentally sound agricultural fungicides. As seen in fenpiclonil, fludioxonil and synthetic derivatives of the strobilurins such as azoxystrobin and krexosim‐methyl, this approach for the development of microbial fungicides has proven to be a promising and effective strategy for developing new fungicides. As a result, microbial metabolites face a revival as lead compounds. Recently, numerous antifungal compounds were discovered from diverse microbial sources using traditional activity‐based screening techniques. These microbial compounds showed potent control efficacy against various plant diseases, including chronic diseases which are difficult to control with conventional synthetic fungicides. Advances in screening systems directed to specific targets of fungal metabolism have increased the opportunities to discover novel antifungal agents with selectivity over non‐target organisms. Microbial metabolites have also been exploited as a source for non‐fungicidal disease control agents that do not inhibit vegetative hyphal growth, but rather interfere specifically with the infection process of pathogenic fungi. The specificity of microbial fungicides is a highly preferred characteristic in terms of impacting the environment, where it is closely related to the occurrence of fungicide resistance. The most recently developed fungicides from microbial metabolites, the strobilurins, provide a cue for the high risk of resistance development of site‐specific fungicides.
Circadian Variation of the Ca2+–PTH Curve during Hypercalcaemia in Dogs
Authors: Domingo V. , López I. , Mendoza F. J. , Rodríguez M. , Aguilera‐Tejero E. , Estepa J. C. 
Published: October 2007

SummaryTo test the hypothesis that the parathyroid hormone (PTH) response to hypercalcaemia is influenced by circadian rhythms, the Ca2+–PTH curve was studied in six dogs after infusion of CaCl2(0.66 mEq/kg/h) at daytime (09:00 h) and at night‐time (21:00 h). Plasma Ca2+and PTH values measured before or after CaCl2infusion were not different at day and at night. However, in the recovery from hypercalcaemia, PTH concentrations were significantly lower (P < 0.05) at 21:00 h (23 ± 7.5 pg/ml at Ca2+ = 1.30 mm) than at 09:00 h (38.8 ± 6.9 pg/ml at Ca2+ = 1.30 mm). In addition, the Ca2+–PTH curve showed hysteresis at daytime (for the same Ca2+concentration, PTH values were higher during recovery than during induction of hypercalcaemia) but not at night‐time (PTH values were lower during recovery than during induction of hypercalcaemia). In conclusion, a circadian variation in the PTH secretory pattern during recovery from hypercalcaemia has been identified in dogs.
Development‐related Expression of KGF and FGF‐10 mRNA in the Canine Prostate Gland
Authors: Shidaifat F. 
Published: October 2007

SummaryKeratinocyte growth factor (KGF) and fibroblast growth factor 10 (FGF‐10) are stromal‐derived growth factors that interact with their epithelial FGFR2 receptors to mediate stromal‐‐epithelial cell interaction within the prostate gland. This study was conducted to compare the development‐related mRNA expression of KGF, FGF‐10 and their receptor FGFR2 in immature and mature canine prostate glands. In addition, their expression levels were correlated with the differentiation of stromal cells using vimentin as a mesenchymal cell marker. Quantitative mRNA expression was assessed by real‐time polymerase chain reaction (PCR) and the results were expressed as relative mRNA expression of the target gene, which was normalized to the GAPDH reference gene. mRNA analysis revealed a differential expression of KGF, FGF‐10 and FGFR2 receptor by the prostate glands of immature and mature dogs. The results showed a 7.3‐ and 9‐fold decrease in mRNA expression of KGF and FGF‐10 by mature and immature prostate glands respectively. However, there was no significant change in FGFR2 receptor mRNA expression by mature or immature prostate glands. This downregulation of KGF and FGF‐10 expression was associated with a 15‐fold decrease in vimentin expression. These results indicate that KGF and FGF‐10 expression varied according to the differentiation status of stromal cells and might reflect differential developmental requirements of immature and mature canine prostate glands.