bluuebunny/crossref_metadata_2025_split huggingface dataset:
CTD phosphatases in the attenuation of wound‐induced transcription of jasmonic acid biosynthetic genes in Arabidopsis
Authors: Matsuda Osamu , Sakamoto Hikaru , Nakao Yoshikazu , Oda Kenji , Iba Koh 
Published: September 2008

SummaryTrienoic fatty acids (TAs), the major constituents in plant membrane lipids, play essential roles in stress signalling as precursors of the phytohormone jasmonic acid (JA). Arabidopsis FAD7 encodes a plastidial ω‐3 fatty acid desaturase, which catalyses the production of TAs. In coordination with other JA‐biosynthetic genes, expression of FAD7 is induced locally by wounding. This provides a feedforward mechanism for the rapid and sustainable accumulation of JA. To identify molecular components involved in this mechanism, a transgenic Arabidopsis line carrying the FAD7 promoter (pFAD7) fused to the firefly luciferase gene (LUC) was constructed. Reciprocal crossing experiments revealed that the induction of FAD7 expression depends largely on JA biosynthesis and the SCFCOI1‐mediated signalling mechanism, whereas JA alone is insufficient for its maximal induction. Full induction required synergistic interactions between JA‐dependent and ‐independent wound signalling mechanisms. A genetic screen for aberrant pFAD7::LUC expression yielded a recessive mutant showing enhanced wound‐induced LUC bioluminescence. The mutation was associated with the cpl1 locus encoding an RNA polymerase II C‐terminal domain (CTD) phosphatase, and conferred wound hyper‐responsiveness on the promoters of several JA‐biosynthetic genes. The picture of signalling mechanisms underlying the wound‐regulated FAD7 expression, and potential roles of CPL proteins as attenuators of wound‐induced JA biosynthesis, are discussed.
Expression of an Escherichia coli antigenic fusion protein comprising the heat labile toxin B subunit and the heat stable toxin, and its assembly as a functional oligomer in transplastomic tobacco plants
Authors: Rosales‐Mendoza Sergio , Alpuche‐Solís Ángel Gabriel , Soria‐Guerra Ruth Elena , Moreno‐Fierros Leticia , Martínez‐González Luzmila , Herrera‐Díaz Areli , Korban Schuyler S. 
Published: September 2008

SummaryEnterotoxigenic Escherichia coli (ETEC) strains are important pathogens in developing countries. Some vaccine formulations containing the heat labile toxin B subunit (LTB) have been used in clinical trials; however, the induction of neutralizing antibodies against the heat‐stable toxin (ST), a poor immunogenic peptide, is necessary, as most ETEC strains can produce both toxins. In this study, a plant optimized synthetic gene encoding for the LTB‐ST fusion protein has been introduced into plastids of tobacco leaf tissues, using biolistic microprojectile bombardment, in an effort to develop a single plant‐based candidate vaccine against both toxins. Transplastomic tobacco plants carrying the LTB‐ST transgene have been recovered. Transgene insertion into the plastid was confirmed by both PCR and Southern blot analysis. GM1‐ELISA revealed that the LTB‐ST fusion protein retained its oligomeric structure, and displayed antigenic determinants for both LTB and ST. Western blot analysis, using LTB antisera, confirmed the presence of a 17‐KDa protein in transplastomic lines, with the correct antigenicity of the fusion protein. Expression levels of this fusion protein in different lines reached up to 2.3% total soluble protein. Oral immunization of mice with freeze‐dried transplastomic tobacco leaves led to the induction of both serum and mucosal LTB‐ST specific antibodies. Following cholera toxin challenge, a decrease of intestinal fluid accumulation was observed in mice immunized with LTB‐ST‐containing tobacco. These findings suggest that tobacco plants expressing LTB‐ST could serve as a plant‐based candidate vaccine model providing broad‐spectrum protection against ETEC‐induced diarrhoeal disease.
PAMP‐induced defense responses in potato require both salicylic acid and jasmonic acid
Authors: Halim Vincentius A. , Altmann Simone , Ellinger Dorothea , Eschen‐Lippold Lennart , Miersch Otto , Scheel Dierk , Rosahl Sabine 
Published: September 2008

SummaryTo elucidate the molecular mechanisms underlying pathogen‐associated molecular pattern (PAMP)‐induced defense responses in potato (Solanum tuberosum), the role of the signaling compounds salicylic acid (SA) and jasmonic acid (JA) was analyzed. Pep‐13, a PAMP from Phytophthora, induces the accumulation of SA, JA and hydrogen peroxide, as well as the activation of defense genes and hypersensitive‐like cell death. We have previously shown that SA is required for Pep‐13‐induced defense responses. To assess the importance of JA, RNA interference constructs targeted at the JA biosynthetic genes, allene oxide cyclase and 12‐oxophytodienoic acid reductase, were expressed in transgenic potato plants. In addition, expression of the F‐box protein COI1 was reduced by RNA interference. Plants expressing the RNA interference constructs failed to accumulate the respective transcripts in response to wounding or Pep‐13 treatment, neither did they contain significant amounts of JA after elicitation. In response to infiltration of Pep‐13, the transgenic plants exhibited a highly reduced accumulation of reactive oxygen species as well as reduced hypersensitive cell death. The ability of the JA‐deficient plants to accumulate SA suggests that SA accumulation is independent or upstream of JA accumulation. These data show that PAMP responses in potato require both SA and JA and that, in contrast to Arabidopsis, these compounds act in the same signal transduction pathway. Despite their inability to fully respond to PAMP treatment, the transgenic RNA interference plants are not altered in their basal defense against Phytophthora infestans.
Sulphur starvation induces the expression of microRNA‐395 and one of its target genes but in different cell types
Authors: Kawashima Cintia Goulart , Yoshimoto Naoko , Maruyama‐Nakashita Akiko , Tsuchiya Yumiko N. , Saito Kazuki , Takahashi Hideki , Dalmay Tamas 
Published: September 2008

SummaryPlants play an important role in the global sulphur cycle because they assimilate sulphur from the environment and build it into methionine and cysteine. Several genes of the sulphur assimilation pathway are regulated by microRNA‐395 (miR395) that is itself induced by a low‐sulphur (−S) environment. Here, we show that the six Arabidopsis miR395 loci are induced differently. We find that MIR395 loci are expressed in the vascular system of roots and leaves and root tips. Induction of miR395 by a −S environment in both roots and leaves suggests that translocation of miR395 from leaves to roots through the phloem is not necessary for plants growing on −S soil/medium. We also demonstrate that induction of miR395 is controlled by SLIM1, a key transcription factor in the sulphur assimilation pathway. Unexpectedly, the mRNA level of a miR395 target gene, SULTR2;1, strongly increases during miR395 induction in roots. We show that the spatial expression pattern of MIR395 transcripts in the vascular system does not appear to overlap with the expression pattern previously reported for SULTR2;1 mRNA. These results illustrate that negative temporal correlation between the expression level of a miRNA and its target gene in a complex tissue cannot be a requirement for target gene validation.
Weed control in conventional and herbicide tolerant winter oilseed rape (Brassica napus) grown in rotations with winter cereals in the UK
Authors: LUTMAN P J W , SWEET J , BERRY K , LAW J , PAYNE R , SIMPSON E , WALKER K , WIGHTMAN P 
Published: September 2008

SummaryTwo winter oilseed rape (Brassica napus) cultivars, tolerant to glyphosate and glufosinate, were compared with a conventional cultivar at three sites over 4 years, in 3‐year crop rotations in the UK. The winter oilseed rape was grown in Years 1 and 4, with winter cereals, which received uniform herbicide treatments, in the intervening years. The second winter oilseed rape treatments were applied to randomised sub‐plots of the original plots. Weed densities were recorded in autumn and spring and weed biomass was measured in summer. At most sites, there was only one application of glufosinate or glyphosate, whereas two products were often used on the conventional variety. The timing of glyphosate and glufosinate application was, on average, 34 days later than that of the conventional broad‐leaved weed control treatments. Overall weed control, across all sites and years, was not statistically different between the conventional, glyphosate and glufosinate treatments. However, glyphosate achieved higher control of individual weed species more frequently than the other treatments. Glufosinate and the conventional treatments were similar in performance. The treatments in Year 1 sometimes affected weed populations in the subsequent cereal crops and, in rare instances, those in the rape in Year 4. Carry‐over effects were small after most treatments. In general, weed survival was greater in the oilseed rape crops, irrespective of the treatment, than it was in the intervening cereal crops.
Inheritance of sulfonylurea resistance in Monochoria vaginalis
Authors: IMAIZUMI T , WANG G X , TOMINAGA T 
Published: September 2008

SummaryThe inheritance of sulfonylurea (SU) resistance in Monochoria vaginalis was investigated based on the bensulfuron‐methyl response phenotypes of F1 plants between SU‐resistant (R) and ‐susceptible (S) and segregation analysis in F2 progenies. Differences of SU resistance between SU‐R biotypes and F1 plants at the recommended field dose were also investigated by comparing shoot dry weight. All F1 plants survived the treatment with 25 g a.i. ha−1 bensulfuron‐methyl, one‐third of the recommended field dose, and showed similar responses to SU‐R plants. Conversely, all F1 plants died or showed extreme necrosis at 225 g a.i. ha−1, three times the recommended field dose, as SU‐S plants. F2 plants were classified as either R or S phenotype. Segregation for resistance to bensulfuron‐methyl in F2 families did not differ from the expected 3:1 (R:S) ratio at 25 g a.i. ha−1. At 225 g a.i. ha−1, the F2 families segregated in a 1:3 (R:S) ratio. These results suggest that SU resistance in M. vaginalis is controlled by a single nuclear allele with resistance being dominant at low dose and susceptibility dominant at high dose. Moreover, F1 plants died or were extremely injured after application of bensulfuron‐methyl at the recommended field dose, although SU‐R biotypes grew normally.
Sorption/desorption behaviour of sulfonylurea herbicides as affected by the addition of fresh and composted olive cake to soil
Authors: DELGADO‐MORENO L , PEÑA A 
Published: September 2008

SummaryThe olive industry generates residues which can be applied as amendments to soils in their original form (olive cake) or after composting or vermicomposting processes. The addition, fresh or incubated, of these amendments to soil and of their different organic fractions was studied in relation to the sorption/desorption of three sulfonylurea herbicides, bensulfuron‐methyl, chlorsulfuron and prosulfuron. Herbicide sorption was low or very low, slightly promoted by the addition of the agricultural by‐products, especially olive cake, and mainly affected by pH of the soil solution, with the organic carbon content having no significant effect on herbicide retention. Desorption was only reduced when fresh olive cake was added. The incubation of soil and amendments for 3 months did not modify herbicide sorption, but made desorption reversible except for olive cake. The transformation of the organic matter of the amendments due to humification and maturity processes are likely to be responsible for this behaviour. Different organic fractions were removed to assess the influence of each fraction on sulfonylurea sorption. Only the removal of all studied organic fractions increased herbicide sorption, revealing the role of humin and mineral fractions in this process. Therefore, the use of organic amendments is not useful for reducing the risk of movement of ionisable molecules in soil.
Herbicides can stimulate plant growth
Authors: CEDERGREEN N 
Published: September 2008

SummaryLow dose stimulations by toxicants have long been observed. Great controversies exist concerning the interpretation of these observations, spanning from believing that they are a general stress response occurring for all chemicals, to simply being an experimental artefact resulting from poorly growing control plants or from biomass allocation between plant parts. This study investigates the growth response and biomass allocation pattern of barley exposed to 10–15 doses of eight different herbicides. The results show that the globally most widely used herbicide, glyphosate, together with the sulfonylurea, metsulfuron‐methyl, can induce a real stimulation in biomass growth of approximately 25% when applied at doses corresponding to 5–10% field rate. The other six herbicides tested did not induce consistent hormesis, thereby undermining the theory of hormesis being a general stress response. Biomass allocations between plant parts did take place, but were not the cause of the hormetic growth stimulations. The results demonstrate that plant physiological responses to low herbicide doses cannot be extrapolated from our knowledge of effects of higher, commercially used, doses. Other physiological mechanisms seem to be triggered in the low dose‐range, and the investigation of these mechanisms poses new challenges for agronomists, environmentalists and plant physiologists.
Shikimate accumulation in nine weedy species following glyphosate application
Authors: MUELLER T C , ELLIS A T , BEELER J E , SHARMA S D , SINGH M 
Published: September 2008

SummaryGlyphosate is commonly used in a variety of weed control scenarios and plants respond biochemically by continuing to attempt to push carbon through the shikimate pathway. The result is an accumulation of shikimate in sensitive plants in the days immediately after application. This research determined shikimate accumulation dynamics in nine problematic plant species from 0 to 6 days after treatment (DAT). Ambrosia artemisiifolia, Trifolium repens and Conyza canadensis showed rising concentrations through 6 DAT to >4000 mg L−1. Chenopodium album, Xanthium strumarium and Urochloa platyphylla showed concentrations levelling off to a constant of about 2000 mg L−1. Ambrosia trifida, Amaranthus palmeri and Polygonum pensylvanicum generally showed lower levels of shikimate accumulation and concentrations were decreasing after 3 DAT. No apparent relationships were evident between shikimate accumulation pattern and plant growth rate or speed of glyphosate activity. There also appeared to be no pattern in the shikimate accumulation trends that would allow for an informed decision as to which of these species would be most likely to develop glyphosate resistance. Shikimate concentrations were in agreement between field and glasshouse conditions for C. canadensis, but did not agree with those from A. palmeri.
Characterisation and molecular basis of ALS inhibitor resistance in the grass weed Alopecurus myosuroides
Authors: MARSHALL R , MOSS S R 
Published: September 2008

SummarySeveral UK populations of the grass weed Alopecurus myosuroides were identified where high proportions of individuals showed resistance to the acetolactate synthase (ALS)‐inhibiting herbicides, mesosulfuron‐methyl + iodosulfuron‐methyl sodium mixture and sulfometuron‐methyl. Screening with sulfometuron, followed by DNA sequencing of the ALS gene from resistant and susceptible individuals, led to the identification of eight populations where a single point mutation segregated with resistance to sulfometuron. All highly resistant individuals from seven of eight populations showed a single‐nucleotide polymorphism (SNP) in the first position of the Pro197 codon of an A. myosuroides ALS gene, conferring a predicted proline to threonine target‐site change. One population showed resistant individuals with single‐nucleotide polymorphism in the second position of the Trp574 codon, conferring a predicted tryptophan to leucine substitution. No other mutations segregating with resistance were found. Enzyme assays confirmed that resistance was due to an altered form of ALS enzyme, which was less susceptible to inhibition by sulfonylureas, making this one of the first fully characterised cases of ALS target‐site resistance in a European grass weed. Increased information regarding the nature and distribution of ALS target‐site mutation may help support sustainable management strategies, allowing continued use of mesosulfuron + iodosulfuron against this weed in the UK.
Weed research: is it delivering what it should?
Authors: MOSS S R 
Published: September 2008

SummaryI believe the overall balance and current direction of much weed research is wrong, with too much emphasis on ‘scientific impact’ at the expense of practical application. For example, despite considerable research effort, Integrated Weed Management has not been widely adopted by farmers. Weed research, as a whole, has delivered less than it should have done in recent years, because of lack of appreciation of the difficulty and costs involved in scaling up experimental results to be applicable at a realistic field scale in real farming systems. In addition, there is often a lack of awareness of the complexities and resources needed to translate research results into actions that farmers, who may be counted in their millions, are willing to adopt. What is needed is truly integrated research, across the whole spectrum from basic to applied, with all elements contributing to real improvements in weed management. It should never be forgotten that, however great the ‘impact’ of a publication, it achieves nothing in terms of improving our ability to manage weeds until the results are used in practice. Effective technology transfer is essential. Weed research is an applied discipline, and the question needs to be asked repeatedly and critically, ‘Why study weeds?’
Solarization for the control ofPueraria montana(kudzu)
Authors: NEWTON CH , NELSON LR , DEWALT SJ , MIKHAILOVA EA , POST CJ , SCHLAUTMAN MA , COX SK , BRIDGES WC , HALL KC 
Published: September 2008

SummaryThe effects of translucent polyethylene sheeting as a thermal covering to eradicatePueraria montana(kudzu) were investigated at Clemson, South Carolina on a clay loam. In 2005, the highest reduction of live root crowns was observed whereP. montanawas covered for the entire growing season (May–October) with a reduction of 42% of live root crowns compared with the control plots. WhereP. montanawas covered for alternate weeks throughout the growing season live root crowns were reduced by 35%. CoveringP. montanafor one week and then uncovering for four weeks repeatedly through the season killed 24% of root crowns. In 2006, the second year of treatment to the same plots, the three solarization treatments had similar efficacy of about 97%. The use of polyethylene sheeting appears not to be cost‐effective for general control of largeP. montanainfestations, but may be useful for small patches.
Complex population history of twoAnopheles dirusmosquito species in Southeast Asia suggests the influence of Pleistocene climate change rather than human‐mediated effects
Authors: O’LOUGHLIN S. M. , OKABAYASHI T. , HONDA M. , KITAZOE Y. , KISHINO H. , SOMBOON P. , SOCHANTHA T. , NAMBANYA S. , SAIKIA P. K. , DEV V. , WALTON C. 
Published: September 2008

AbstractAnopheles dirusandAnopheles baimaiiare closely related species which feed on primates, particularly humans, and transmit malaria in the tropical forests of mainland Southeast Asia. Here, we report an in‐depth phylogeographic picture based on 269 individuals from 21 populations from mainland Southeast Asia. Analysis of 1537 bp of mtDNA sequence revealed that the population history ofA. baimaiiis far more complex than previously thought. An old expansion (pre‐300 kyr BP) was inferred in northern India/Bangladesh with a wave of south‐eastwards expansion arriving at the Thai border (ca 135–173 kyr BP) followed by leptokurtic dispersal very recently (ca 16 kyr BP) into peninsular Thailand. The long and complex population history of these anthropophilic species suggests their expansions are not in response to the relatively recent (ca 40 kyr BP) human expansions in mainland Southeast Asia but, rather, fit well with our understanding of Pleistocene climatic change there.
Evolutionary impacts of hybridization and interspecific gene flow on an obligately estuarine fish
Authors: ROBERTS D. G. , GRAY C. A. , WEST R. J. , AYRE D. J. 
Published: September 2008

AbstractFor free‐spawning estuarine taxa, gene flow among estuaries may occur via hybridization with mobile congeners. This phenomenon has rarely been investigated, but is probably susceptible to anthropogenic disturbance. In eastern Australia, the estuarine Black BreamAcanthopagrus butcheriand marine Yellowfin BreamAcanthopagrus australishave overlapping distributions and the potential to hybridize. We used surveys of microsatellite and mtDNA variation in 565 adults from 25 estuaries spanning their distributional range to characterize the species and their putative hybrids. Hybrids were widespread (68% of estuaries) and hybrid frequencies varied greatly among estuaries (0–58%). Most (88%) were classed as advanced generation backcrosses withA. butcheriand displayedA. butcherimtDNA haplotypes. We found most hybrids in the three estuaries within the zone of sympatry (57%). Our study highlights the underemphasized importance of estuaries as sites of hybridization and suggests that hybridization is driven both by opportunity for contact and human activity.
Genetic analysis of Mexican Criollo cattle populations
Authors: Ulloa‐Arvizu R. , Gayosso‐Vázquez A. , Ramos‐Kuri M. , Estrada F.J. , Montaño M. , Alonso R.A. 
Published: September 2008

SummaryThe objective of this study was to evaluate the genetic structure of Mexican Criollo cattle populations using microsatellite genetic markers. DNA samples were collected from 168 animals from four Mexican Criollo cattle populations, geographically isolated in remote areas of Sierra Madre Occidental (West Highlands). Also were included samples from two breeds with Iberian origin: the fighting bull (n = 24) and the milking central American Criollo (n = 24) and one Asiatic breed: Guzerat (n = 32). Genetic analysis consisted of the estimation of the genetic diversity in each population by the allele number and the average expected heterozygosity found in nine microsatellite loci. Furthermore, genetic relationships among the populations were defined by their genetic distances. Our data shows that Mexican cattle populations have a relatively high level of genetic diversity based either on the mean number of alleles (10.2–13.6) and on the expected heterozygosity (0.71–0.85). The degree of observed homozygosity within the Criollo populations was remarkable and probably caused by inbreeding (reduced effective population size) possibly due to reproductive structure within populations. Our data shows that considerable genetic differentiation has been occurred among the Criollo cattle populations in different regions of Mexico.