bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climate change, anthropogenic disturbance and the northward range expansion of Lactuca serriola (Asteraceae)
Authors: D’Andrea Luigi , Broennimann Olivier , Kozlowski Gregor , Guisan Antoine , Morin Xavier , Keller‐Senften Julia , Felber François 
Published: February 2009

AbstractAim  The distribution range of Lactuca serriola, a species native to the summer‐dry mediterranean climate, has expanded northwards during the last 250 years. This paper assesses the influence of climate on the range expansion of this species and highlights the importance of anthropogenic disturbance to its spread.Location  Central and Northern Europe.Methods  Data on the geographic distribution of L. serriola were assembled through a literature search as well as through floristic and herbarium surveys. Maps of the spread of L. serriola in Central and Northern Europe were prepared based on herbarium data. The spread was assessed more precisely in Germany, Austria and Great Britain by pooling herbarium and literature data. We modelled the bioclimatic niche of the species using occurrence and climatic data covering the last century to generate projections of suitable habitats under the climatic conditions of five time periods. We tested whether the observed distribution of L. serriola could be explained for each time period, assuming that the climatic niche of the species was conserved across time.Results  The species has spread northwards since the beginning of the 19th century. We show that climate warming in Europe increased the number of sites suitable for the species at northern latitudes. Until the late 1970s, the distribution of the species corresponded to the climatically suitable sites available. For the last two decades, however, we could not show any significant relationship between the increase in suitable sites and the distributional range change of L. serriola. However, we highlight potential areas the species could spread to in the future (Great Britain, southern Scandinavia and the Swedish coast). It is predominantly non‐climatic influences of global change that have contributed to its rapid spread.Main conclusions  The observation that colonizing species are not filling their climatically suitable range might imply that, potentially, other ruderal species could expand far beyond their current range. Our work highlights the importance of historical floristic and herbarium data for understanding the expansion of a species. Such historical distributional data can provide valuable information for those planning the management of contemporary environmental problems, such as species responses to environmental change.
Predicting ischaemic stroke subtype from presenting systolic blood pressure: the BASIC Project
Authors: Meurer W. J. , Sánchez B. N. , Smith M. A. , Lisabeth L. D. , Majersik J. J. , Brown D. L. , Uchino K. , Bonikowski F. P. , Mendizabal J. E. , Zahuranec D. B. , Morgenstern L. B. 
Published: February 2009

Abstract.Objective.  We hypothesized that low presenting systolic blood pressure (SBP) predicted cardioembolic stroke aetiology.Design.  Active and passive surveillance were used to identify all ischaemic strokes as part of the Brain Attack Surveillance in Corpus Christi (BASIC) population‐based study. Multinomial logistic regression was used to examine the association between stroke subtype and first documented SBP in the medical record.Setting.  Nueces County, TX, USA (313 645 residents in 2000). The community is urban with the majority of the population residing in the city of Corpus Christi. The area is served by seven adult acute care hospitals.Patients.  Three hundred and eight cases with completed ischaemic stroke and determined subtype aetiology between January 2000 and December 2002.Results.  Lower presenting SBP was associated with stroke subtype (P = 0.001). This association remained significant in the final model adjusted for age and history of coronary artery disease. The odds of cardioembolic versus small vessel occlusion increased by 20% (OR = 1.20, 95% CI: 1.07–1.35) for every 10 mmHg decrease in presenting SBP. Other covariates including race/ethnicity, gender, history of hypertension, and diabetes were neither significant predictors of stroke subtype, nor did they confound the association of SBP and stroke subtype. A 5 year increase in age increased the odds of cardioembolic subtype by 25% (OR = 1.25, 95% CI: 1.07–1.47).Conclusions.  Lower initial SBP and older age at ischaemic stroke presentation were associated with cardioembolic stroke. Suspicion of cardioembolic stroke should be increased in those presenting with low SBP.
The emerging concept of functional amyloid
Authors: Maury C. P. J. 
Published: February 2009

Abstract.Although amyloid has usually been considered a pathological structure, growing evidence indicates that amyloid may also be a productive part of cell biology contributing to normal physiology. In fact, amyloid formation seems to be an intrinsic propensity of polypeptides in general and the amyloid β‐fold an evolutionary highly conserved structure. Functional amyloids have been found in a wide range of organisms, from bacteria to mammals, with functions as diverse as biofilm formation, development of aerial structures, scaffolding, regulation of melanin synthesis, epigenetic control of polyamines and information transfer. Obviously, organisms have evolved taking advantage of the canonical amyloid β‐sheet fold, a conformation that possesses both high resistance to proteolysis, self‐replicative properties and capability to function as a molecular memory.
Genomic dissection of drought resistance in durum wheat × wild emmer wheat recombinant inbreed line population
Authors: PELEG ZVI , FAHIMA TZION , KRUGMAN TAMAR , ABBO SHAHAL , YAKIR DAN , KOROL ABRAHAM B. , SARANGA YEHOSHUA 
Published: February 2009

ABSTRACTDrought is the major factor limiting wheat productivity worldwide. The gene pool of wild emmer wheat,Triticum turgidumssp.dicoccoides, harbours a rich allelic repertoire for morpho‐physiological traits conferring drought resistance. The genetic and physiological bases of drought responses were studied here in a tetraploid wheat population of 152 recombinant inbreed lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (acc# G18‐16), under contrasting water availabilities. Wide genetic variation was found among RILs for all studied traits. A total of 110 quantitative trait loci (QTLs) were mapped for 11 traits, with LOD score range of 3.0–35.4. Several QTLs showed environmental specificity, accounting for productivity and related traits under water‐limited (20 QTLs) or well‐watered conditions (15 QTLs), and in terms of drought susceptibility index (22 QTLs). Major genomic regions controlling productivity and related traits were identified on chromosomes 2B, 4A, 5A and 7B. QTLs for productivity were associated with QTLs for drought‐adaptive traits, suggesting the involvement of several strategies in wheat adaptation to drought stress. Fifteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. The identified QTLs may facilitate the use of wild alleles for improvement of drought resistance in elite wheat cultivars.
Illuminated behaviour: phytochrome as a key regulator of light foraging and plant anti‐herbivore defence
Authors: BALLARÉ CARLOS L. 
Published: February 2009

ABSTRACTIn many ecological scenarios, the success of an individual plant is defined by the behavioural decisions that it makes when confronted with the risks of competition with other plants, and biomass losses to insect herbivores. These decisions involve expression of shade avoidance responses and induced chemical defences. Because these responses are costly, they frequently engender resource allocation dilemmas. In this review, I discuss the mechanisms that trigger adaptive responses to competitors and herbivores, highlighting the role of phytochromes as central organizers of the overall resource allocation strategy of plants. Phytochromes sense the reduction in the red to far‐red (R : FR) ratio of sunlight caused by the proximity of other plants. Shade‐intolerant plants respond to low R : FR ratios with shade avoidance behaviours and reduced investment in defence. Pfr depletion leads to increased stability of growth‐promoting phytochrome‐interacting factors (PIFs), and results in the production of auxins and gibberellins, degradation of DELLA proteins, which are repressors of PIFs, and reduced sensitivity to jasmonates. Thus, phytochrome appears to fulfil its organizational role by regulating the relative strength of the signalling circuits controlled by growth‐related and defence‐related hormones. I point out cases of signalling redundancy and discuss the significance of recent work on hormone signalling for our understanding of the mechanisms that control adaptive plant behaviour.
cpFBPaseII, a novel redox‐independent chloroplastic isoform of fructose‐1,6‐bisphosphatase
Authors: SERRATO ANTONIO JESÚS , YUBERO‐SERRANO ELENA MARÍA , SANDALIO LUISA MARÍA , MUÑOZ‐BLANCO JUAN , CHUECA ANA , CABALLERO JOSÉ LUIS , SAHRAWY MARIAM 
Published: February 2009

ABSTRACTA full‐length FBPase cDNA has been isolated from Fragaria × ananassa (strawberry) corresponding to a novel putative chloroplastic FBPase but lacking the regulatory redox domain, a characteristic of the plastidial isoenzyme (cpFBPaseI). Another outstanding feature of this novel isoform, called cpFBPaseII, is the absence of the canonical active site. Enzymatic assays with cpFBPaseII evidenced clear Mg2+‐dependent FBPase activity and a Km for fructose‐1,6‐bisphosphate (FBP) of 1.3 mm. Immunolocalization experiments and chloroplast isolation confirmed that the new isoenzyme is located in the stroma. Nevertheless, unlike cpFBPaseI, which is redox activated, cpFBPaseII did not increase its activity in the presence of either DTT or thioredoxin f (TRX f) and is resistant to H2O2 inactivation. Additionally, the novel isoform was able to complement the growth deficiency of the yeast FBP1 deletion fed with a non‐fermentable carbon source. Furthermore, orthologues are restricted to land plants, suggesting that cpFBPaseII is a novel and an intriguing chloroplastic FBPase that emerged late in the evolution of photosynthetic organisms, possibly because of a pressing need of land plants.
Depth and controls of Ca‐rhodochrosite precipitation in bioturbated sediments of the Eastern Equatorial Pacific, ODP Leg 201, Site 1226 and DSDP Leg 68, Site 503
Authors: MEISTER PATRICK , BERNASCONI STEFANO M. , AIELLO IVANO W. , VASCONCELOS CRISÓGONO , MCKENZIE JUDITH A. 
Published: February 2009

AbstractThe occurrence of early diagenetic Ca‐rhodochrosite [(Mn,Ca)CO3] is reported in association with ‘griotte’‐type nodular limestones from basinal settings in the geological record; however, without the comparison of analogous modern examples, the controls on precipitation remain speculative. Here the findings of four layers of primary Ca‐rich rhodochrosite recovered from a modern deep‐sea setting in the Eastern Equatorial Pacific, from bioturbated sediments 300 m below sea floor, are reported (Ocean Drilling Program, Leg 201, Site 1226). The mineralogy is similar to cements in burrows recovered during Deep Sea Drilling Project Leg 68 at Eastern Equatorial Pacific Site 503 and from Ca‐rhodochrosite laminae in sediments of the central Baltic Sea. Petrographic relationships and constant oxygen isotopic compositions in the Ca‐rhodochrosite around 5‰ at all depths indicate a shallow burial depth of formation. The onset of 1‰ heavier oxygen isotope composition of Ca‐rhodochrosite at Site 503, about 30 m below the Pliocene/Pleistocene boundary, further suggests that precipitation occurs in the range of 30 m below sea floor. The approximate depth of formation allowed an approximate empirical fractionation factor for marine Ca‐rhodochrosite to be constrained that strongly differs from previously published theoretical values. Based on the approximate precipitation depth, authigenic Ca‐rhodochrosite forms within the SO42−‐reduction zone. Moderately negative δ13C values (around −3‰) and total organic carbon lower than 2 wt% indicate a relatively low contribution of CO32− from organic C mineralization within the expanded redox zonation in the Eastern Equatorial Pacific. It is suggested that the alkalinity is increased by a rise in pH at focused sites of Mn‐reduction coupled with S2− oxidation. High concentrations of Mn‐oxide can accumulate in layers or burrows because of Mn‐cycling in suboxic sediments as suggested for the Baltic Sea Ca‐rhodochrosites. This study demonstrates how early diagenetic precipitates document biogeochemical processes from past diagenetic systems.
Apoplastic plant subtilases support arbuscular mycorrhiza development in Lotus japonicus
Authors: Takeda Naoya , Sato Shusei , Asamizu Erika , Tabata Satoshi , Parniske Martin 
Published: February 2009

SummaryIn the arbuscular mycorrhiza (AM) symbiosis, plant roots accommodate Glomeromycota fungi within an intracellular compartment, the arbuscule. At this symbiotic interface, fungal hyphae are surrounded by a plant membrane, which creates an apoplastic compartment, the periarbuscular space (PAS) between fungal and plant cell. Despite the importance of the PAS for symbiotic signal and metabolite exchange, only few of its components have been identified. Here we show that two apoplastic plant proteases of the subtilase family are required for AM development. SbtM1 is the founder member of a family of arbuscular mycorrhiza‐induced subtilase genes that occur in at least two clusters in the genome of the legume Lotus japonicus. A detailed expression analysis by RT‐PCR revealed that SbtM1, SbtM3, SbtM4 and the more distantly related SbtS are all rapidly induced during development of arbuscular mycorrhiza, but only SbtS and SbtM4 are also up‐regulated during root nodule symbiosis. Promoter–reporter fusions indicated specific activation in cells that are adjacent to intra‐radical fungal hyphae or in cells that harbour them. Venus fluorescent protein was observed in the apoplast and the PAS when expressed from a fusion construct with the SbtM1 signal peptide or the full‐length subtilase. Suppression of SbtM1 or SbtM3 by RNAi caused a decrease in intra‐radical hyphae and arbuscule colonization, but had no effect on nodule formation. Our data indicate a role for these subtilases during the fungal infection process in particular arbuscule development.
DWARF AND LOW‐TILLERING, a new member of the GRAS family, plays positive roles in brassinosteroid signaling in rice
Authors: Tong Hongning , Jin Yun , Liu Wenbo , Li Feng , Fang Jun , Yin Yanhai , Qian Qian , Zhu Lihuang , Chu Chengcai 
Published: February 2009

SummaryRapid progress has been made regarding the understanding of brassinosteroid (BR) signaling in Arabidopsis. However, little is known about BR signaling in monotyledons. Here, we characterized a rice dwarf and low‐tillering (dlt) mutant and cloned the corresponding gene via map‐based cloning. DLT encodes a new member of the plant‐specific GRAS family. The dwarf phenotype of dlt is similar to BR‐deficient or signaling mutants in rice. In addition, both lamina bending and coleoptile elongation assays show that dlt is insensitive or much less responsive to brassinolide (BL), the most active BR, suggesting that DLT is involved in BR signaling. Consistent with this conclusion, the accumulation of transcripts of BR biosynthesis genes in the dlt mutant indicated that DLT is involved in feedback inhibition of BR biosynthesis genes. In addition, transcription of several other BR‐regulated genes is altered in the dlt mutant. Finally, consistent with the fact that DLT is also negatively feedback‐regulated by BR treatment, a gel mobility shift assay showed that OsBZR1 can bind to the DLT promoter through the BR‐response element. Taken together, these studies have enabled us to identify a new signaling component that is involved in several specific BR responses in rice.
A microarray‐based genotyping and genetic mapping approach for highly heterozygous outcrossing species enables localization of a large fraction of the unassembled Populus trichocarpa genome sequence
Authors: Drost Derek R. , Novaes Evandro , Boaventura‐Novaes Carolina , Benedict Catherine I. , Brown Ryan S. , Yin Tongming , Tuskan Gerald A. , Kirst Matias 
Published: February 2009

SummaryMicroarrays have demonstrated significant power for genome‐wide analyses of gene expression, and recently have also revolutionized the genetic analysis of segregating populations by genotyping thousands of loci in a single assay. Although microarray‐based genotyping approaches have been successfully applied in yeast and several inbred plant species, their power has not been proven in an outcrossing species with extensive genetic diversity. Here we have developed methods for high‐throughput microarray‐based genotyping in such species using a pseudo‐backcross progeny of 154 individuals of Populus trichocarpa and P. deltoides analyzed with long‐oligonucleotide in situ‐synthesized microarray probes. Our analysis resulted in high‐confidence genotypes for 719 single‐feature polymorphism (SFP) and 1014 gene expression marker (GEM) candidates. Using these genotypes and an established microsatellite (SSR) framework map, we produced a high‐density genetic map comprising over 600 SFPs, GEMs and SSRs. The abundance of gene‐based markers allowed us to localize over 35 million base pairs of previously unplaced whole‐genome shotgun (WGS) scaffold sequence to putative locations in the genome of P. trichocarpa. A high proportion of sampled scaffolds could be verified for their placement with independently mapped SSRs, demonstrating the previously un‐utilized power that high‐density genotyping can provide in the context of map‐based WGS sequence reassembly. Our results provide a substantial contribution to the continued improvement of the Populus genome assembly, while demonstrating the feasibility of microarray‐based genotyping in a highly heterozygous population. The strategies presented are applicable to genetic mapping efforts in all plant species with similarly high levels of genetic diversity.
Nuclear accumulation of the ankyrin repeat protein ANK1 enhances the auxin‐mediated transcription accomplished by the bZIP transcription factors BZI‐1 and BZI‐2
Authors: Böttner Stefan , Iven Tim , Carsjens Caroline S. , Dröge‐Laser Wolfgang 
Published: February 2009

SummaryThe tobacco (Nicotiana tabacum) basic leucine zipper (bZIP) transcription factor BZI‐1 has been implicated in auxin‐mediated gene regulation. Yeast two‐hybrid analysis has led to the identification of two BZI‐1 protein interaction partners: the heterodimerizing bZIP factor BZI‐2 and an ankyrin repeat domain protein, ANK1. Analysis in transgenic plants confirms that low levels of functional BZI‐1, BZI‐2 and ANK1 result in reduced auxin responses. This finding indicates that the three proteins act in the same functional context. The in vivo interaction of ANK1 and BZI‐1 has been confirmed by protoplast two‐hybrid analysis, as well as by bimolecular fluorescence complementation (BiFC) studies. Whereas YFP‐BZI‐1 has been found to be localized in the nucleus, YFP‐ANK1 resides in the cytosol. Nevertheless, the inhibition of nuclear export with the inhibitor leptomycin B (LMB) and the co‐expression with BZI‐1, as well as treatment with auxin, results in the accumulation of YFP‐ANK1 in the nucleus. Whereas BZI‐1 is a weak activator, BZI‐1/BZI‐2 heterodimers efficiently support transcription. Importantly, conditions that lead to the accumulation of ANK1 in the nucleus, such as the expression of an ANK1 protein fused to a nuclear localization sequence (NLS) or auxin treatment, lead to a significant enhancement of BZI‐1/BZI‐2‐mediated transcription. We therefore propose a mechanism in which the nuclear accumulation of ANK1 enhances BZI‐1/BZI‐2‐mediated transcription in an auxin‐dependent manner, presumably facilitated by protein–protein interaction. In summary, this study defines novel components in auxin‐dependent signalling and transcriptional control.
Plant extracellular ATP signalling by plasma membrane NADPH oxidase and Ca2+channels
Authors: Demidchik Vadim , Shang Zhonglin , Shin Ryoung , Thompson Elinor , Rubio Lourdes , Laohavisit Anuphon , Mortimer Jennifer C. , Chivasa Stephen , Slabas Antoni R. , Glover Beverley J. , Schachtman Daniel P. , Shabala Sergey N. , Davies Julia M. 
Published: February 2009

SummaryExtracellular ATP regulates higher plant growth and adaptation. The signalling events may be unique to higher plants, as they lack animal purinoceptor homologues. Although it is known that plant cytosolic free Ca2+can be elevated by extracellular ATP, the mechanism is unknown. Here, we have studied roots ofArabidopsis thalianato determine the events that lead to the transcriptional stress response evoked by extracellular ATP. Root cell protoplasts were used to demonstrate that signalling to elevate cytosolic free Ca2+is determined by ATP perception at the plasma membrane, and not at the cell wall. Imaging revealed that extracellular ATP causes the production of reactive oxygen species in intact roots, with the plasma membrane NADPH oxidase AtRBOHC being the major contributor. This resulted in the stimulation of plasma membrane Ca2+‐permeable channels (determined using patch‐clamp electrophysiology), which contribute to the elevation of cytosolic free Ca2+. Disruption of this pathway in theAtrbohCmutant impaired the extracellular ATP‐induced increase in reactive oxygen species (ROS), the activation of Ca2+channels, and the transcription of the MAP kinase3 gene that is known to be involved in stress responses. This study shows that higher plants, although bereft of purinoceptor homologues, could have evolved a distinct mechanism to transduce the ATP signal at the plasma membrane.
The timing of nectar secretion in staminal and staminodial glands in Lauraceae
Authors: Rohwer J. G. 
Published: February 2009

AbstractThe flowers of many Lauraceae have two kinds of glandular organ: paired glands at the base of the filaments of the third androecial whorl, and staminodes with a glandular head, corresponding to a fourth, sterile androecial whorl. So far, it is unknown why there are two different kinds of organ with apparently the same function. Observations now show that the staminal and the staminodial glands secrete nectar at different times in the heterodichogamous flowering cycle, and are therefore essential for the pollination of bisexual Lauraceae flowers.