bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell‐wall carbohydrates and their modification as a resource for biofuels
Authors: Pauly Markus , Keegstra Kenneth 
Published: May 2008

SummaryPlant cell walls represent the most abundant renewable resource on this planet. Despite their great abundance, only 2% of this resource is currently used by humans. Hence, research into the feasibility of using plant cell walls in the production of cost‐effective biofuels is desirable. The main bottleneck for using wall materials is the recalcitrance of walls to efficient degradation into fermentable sugars. Manipulation of the wall polysaccharide biosynthetic machinery or addition of wall structure‐altering agents should make it possible to tailor wall composition and architecture to enhance sugar yields upon wall digestion for biofuel fermentation. Study of the biosynthetic machinery and its regulation is still in its infancy and represents a major scientific and technical research challenge. Of course, any change in wall structure to accommodate cost‐efficient biofuel production may have detrimental effects on plant growth and development due to the diverse roles of walls in the life of a plant. However, the diversity and abundance of wall structures present in the plant kingdom gives hope that this challenge can be met.
Plant surface lipid biosynthetic pathways and their utility for metabolic engineering of waxes and hydrocarbon biofuels
Authors: Jetter Reinhard , Kunst Ljerka 
Published: May 2008

SummaryDue to their unique physical properties, waxes are high‐value materials that are used in a variety of industrial applications. They are generated by chemical synthesis, extracted from fossil sources, or harvested from a small number of plant and animal species. As a result, the diversity of chemical structures in commercial waxes is low and so are their yields. These limitations can be overcome by engineering of wax biosynthetic pathways in the seeds of high‐yielding oil crops to produce designer waxes for specific industrial end uses. In this review, we first summarize the current knowledge regarding the genes and enzymes generating the chemical diversity of cuticular waxes that accumulate at the surfaces of primary plant organs. We then consider the potential of cuticle biosynthetic genes for biotechnological wax production, focusing on selected examples of wax ester chain lengths and isomers. Finally, we discuss the genes/enzymes of cuticular alkane biosynthesis and their potential in future metabolic engineering of plants for the production of renewable hydrocarbon fuels.
Microalgal triacylglycerols as feedstocks for biofuel production: perspectives and advances
Authors: Hu Qiang , Sommerfeld Milton , Jarvis Eric , Ghirardi Maria , Posewitz Matthew , Seibert Michael , Darzins Al 
Published: May 2008

SummaryMicroalgae represent an exceptionally diverse but highly specialized group of micro‐organisms adapted to various ecological habitats. Many microalgae have the ability to produce substantial amounts (e.g. 20–50% dry cell weight) of triacylglycerols (TAG) as a storage lipid under photo‐oxidative stress or other adverse environmental conditions. Fatty acids, the building blocks for TAGs and all other cellular lipids, are synthesized in the chloroplast using a single set of enzymes, of which acetyl CoA carboxylase (ACCase) is key in regulating fatty acid synthesis rates. However, the expression of genes involved in fatty acid synthesis is poorly understood in microalgae. Synthesis and sequestration of TAG into cytosolic lipid bodies appear to be a protective mechanism by which algal cells cope with stress conditions, but little is known about regulation of TAG formation at the molecular and cellular level. While the concept of using microalgae as an alternative and renewable source of lipid‐rich biomass feedstock for biofuels has been explored over the past few decades, a scalable, commercially viable system has yet to emerge. Today, the production of algal oil is primarily confined to high‐value specialty oils with nutritional value, rather than commodity oils for biofuel. This review provides a brief summary of the current knowledge on oleaginous algae and their fatty acid and TAG biosynthesis, algal model systems and genomic approaches to a better understanding of TAG production, and a historical perspective and path forward for microalgae‐based biofuel research and commercialization.
The calmodulin‐binding protein kinase 3 is part of heat‐shock signal transduction in Arabidopsis thaliana
Authors: Liu Hong‐Tao , Gao Fei , Li Guo‐Liang , Han Jin‐Long , Liu De‐Long , Sun Da‐Ye , Zhou Ren‐Gang 
Published: May 2008

SummaryBased on our previous findings, we proposed a pathway for the participation of Ca2+/calmodulin (CaM) in heat‐shock (HS) signal transduction. The specific mechanism by which CaM regulates activation of heat‐shock transcription factors (HSFs) is not known. CaM‐binding protein kinases (CBK) are the most poorly understood of the CaM target proteins in plants. In this study, using a yeast two‐hybrid assay, we found that AtCBK3 interacts with AtHSFA1a. Fluorescence resonance energy transfer was used to confirm the interaction between AtCBK3–YFP and AtHSFA1a–CFP. Furthermore, we demonstrate that purified recombinant AtCBK3 phosphorylated recombinant AtHSFA1a in vitro. We also describe the results of both downregulation of AtCBK3 expression and ectopic overexpression in Arabidopsis thaliana. The T‐DNA insertion AtCBK3 knockout lines had impaired basal thermotolerance, which could be complemented by transformation of plants with the native gene. Overexpression of AtCBK3 resulted in plants with increased basal thermotolerance. Results from real‐time quantitative PCR and protein gel‐blot analyses suggest that AtCBK3 regulates transcription of heat‐shock protein (HSP) genes and synthesis of HSPs. The binding activity of HSF to the heat‐shock element (HSE), the mRNA level of HSP genes and synthesis of HSPs were upregulated in AtCBK3‐overexpressing lines after HS, but downregulated in AtCBK3 null lines. These results indicate that AtCBK3 controls the binding activity of HSFs to HSEs by phosphorylation of AtHSFA1a, and is an important component of the HS signal transduction pathway.
Genetic and physical interaction suggest that BARREN STALK1 is a target of BARREN INFLORESCENCE2 in maize inflorescence development
Authors: Skirpan Andrea , Wu Xianting , McSteen Paula 
Published: May 2008

SummaryOrganogenesis in plants is controlled by polar auxin transport. In maize (Zea mays), barren inflorescence2 (bif2) encodes a co‐ortholog of the serine/threonine protein kinase PINOID (PID), which regulates auxin transport in Arabidopsis. In this paper, we report that the basic helix‐loop‐helix transcription factor BARREN STALK1 (BA1) is a putative target of BIF2, revealing a previously unknown function of BIF2 in the nucleus. Both bif2 and ba1 are required for axillary meristem initiation during inflorescence and vegetative development in maize. Using a yeast two‐hybrid approach, we identified BA1 as an interacting partner with BIF2. We confirmed the interaction by in vitro pull‐down assays, and demonstrated that BIF2 phosphorylates BA1 in vitro. Previously, RNA in situ hybridization showed that bif2 and ba1 are both expressed during axillary meristem initiation. Here, we heterologously expressed BIF2 and BA1, and found that they co‐localize in the nucleus. Based on these findings, we propose that in addition to regulating auxin transport at the cell periphery, BIF2 also functions in the nucleus by interacting with BA1 to promote axillary meristem initiation. Double mutant analysis is consistent with these results, showing that bif2 and ba1 have overlapping as well as unique roles in inflorescence development.
A new whole‐mount DNA quantification method and the analysis of nuclear DNA content in the stem‐cell niche of Arabidopsis roots
Authors: Willemse Joost , Kulikova Olga , De Jong Hans , Bisseling Ton 
Published: May 2008

SummaryA semi‐automated method to quantify fluorescence intensity of objects in intact organs and tissues, composed of several cell layers, has been designed. The method has been developed on whole‐mount propidium‐iodide stained Arabidopsis thaliana (Arabidopsis) root tips, in which the DNA content of individual nuclei could be quantified. A diameter of less than 150 μm makes this organ most appropriate for whole‐mount imaging. Further advantages are the lack of chlorophyll and transparent cell walls, with only a little background fluorescence. The method has a great advantage over flow cytometry, as the information regarding the positions of nuclei is maintained, and nuclei with aberrant DNA content can be re‐assessed individually, which facilitates the efficient distinction between technical artefact and aberrant DNA content. Our averaging 3D method calculates the average of the summed fluorescence intensities of all sections of a nucleus and interpolates the missing sections, thereby allowing for the correction of detection problems. Furthermore, this method has the advantage of detecting objects in tissues covering multiple cell layers. The results of our method in Arabidopsis root tips showed that the quiescent centre cells, which rarely divide, are diploid, and are arrested in G1 or G0. Most stem cells, with the exception of those of the vascular tissue, are diploid cells, and their rather low division rate is caused by an elongated G1 phase. In contrast, the majority of the vascular stem cells are tetraploid.
SOC1 translocated to the nucleus by interaction with AGL24 directly regulates LEAFY
Authors: Lee Jungeun , Oh Mijin , Park Hanna , Lee Ilha 
Published: May 2008

Summary SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) is one of the flowering pathway integrators and regulates the expression of LEAFY (LFY), which links floral induction and floral development. However, the mechanism by which SOC1, a MADS box protein, regulates LFY has proved elusive. Here, we show that SOC1 directly binds to the distal and proximal region of the LFY promoter where critical cis‐elements are located. Intragenic suppressor mutant analysis shows that a missense mutation in the MADS box of SOC1 causes loss of binding to the LFY promoter as well as suppression of the flowering promotion function. The full‐length SOC1 protein locates in the cytoplasm if expressed alone in protoplast transient expression assay, but relocates to the nucleus if expressed with AGAMOUS‐LIKE 24 (AGL24), another flowering pathway integrator and a MADS box protein. The domain analysis shows that co‐localization of SOC1 and AGL24 is mediated by the MADS box and the intervening region of SOC1. Finally, we show that LFY is expressed only in those tissues where SOC1 and AGL24 expressions overlap. Thus, we propose that heterodimerization of SOC1 and AGL24 is a key mechanism in activating LFY expression.
Seasonal influences on quantitative changes in sweat‐associated anatomy in native and thoroughbred horses
Authors: Sneddon Jennifer C. , Ritruechai Pattama , De Yanés Gesa Staats , Howard C. Vyvyan 
Published: May 2008

AbstractStereological techniques were used to assess seasonal influences on morphometric characteristics of hair follicles, sweat and sebaceous glands in abattoir pelts of ponies (PN), thoroughbred (TB) and non‐thoroughbred (NTB) horses. Volume density of sweat glands increased significantly from winter (0.061) to summer (0.098) in TB, and showed no change in NTB and a positive tendency in PN. There might be a body surface area : volume effect for sweat gland parameters as PN had smaller values than either TB or NTB, probably attributable to control of heat loss in winter. In summer, the skin remained thick and the volume density of sebaceous glands was increased in NTB, in contrast to TB where both were decreased. It is possible that in summer, sebum has a particular importance in NTB to enhance wicking of sweat through the pelt. TB showed significantly higher volume measurements of sebaceous glands than NTB and PN for winter: sebum has probably a special importance for water‐proofing in TB in winter. PN showed no significant seasonal changes in sebaceous glands, but had a thinner summer skin. Winter values for hair follicle volume density between equine groups were similar (TB, NTB 0.066; PN 0.059), as was skin thickness (1.14–1.19 mm). The volume density lowered significantly in summer in TB and NTB. The volume of hair follicles under a unit area of skin surface decreased significantly in TB and nonsignificantly in NTB and PN. The seasonal adaptations of the skin shown here were most pronounced in TB and differed between breeds.
Seed production and subsequent seed germination of Senecio vulgaris (groundsel) grown alone or in autumn‐sown crops
Authors: LUTMAN P J W , BERRY K J , FREEMAN S E 
Published: May 2008

Summary Senecio vulgaris is a common weed of agriculture in the UK, but is also of food value to invertebrates and birds. Thus, it may be beneficial to retain it within agricultural ecosystems to enhance overall biodiversity. A less intensive approach to weed management requires a sound understanding of weed population dynamics so as to avoid unacceptable population growth. Experiments were carried out in 2003 and 2004 to assess seed production, and subsequent germination, by S. vulgaris growing alone, in winter wheat, or in winter field beans. Plant and seed samples were collected during May and June. There was a strong allometric relationship between capsule number and plant weight, irrespective of the year or the presence of crop competition. Numbers of seeds/capsule varied slightly from 51 to 66 seeds per capsule. Plants growing alone were estimated to produce 8471 to 12 887 seeds per plant, whilst those in wheat only 923 to 2156. Germination tests in Petri dishes in incubators showed that virtually all seeds were viable and germinated under daily alternating light:dark conditions within 10 days. Seeds in continuous dark germinated less readily, reaching only 30% after 21 days. On the basis of this and other published work, it would appear that the retention of S. vulgaris in arable fields will not pose a major threat to the long‐term viability of crop production.
Using genomic biology to study liver metabolism*
Authors: Swanson K. S. 
Published: May 2008

SummaryThe liver plays a central role in coordinating the body’s metabolism, including glucose homeostasis, xenobiotic metabolism and detoxification, and steroid hormone synthesis and degradation. Many of the regulatory effects in response to diet initially occur in the liver, which then modulates the activities of other organs in terms of nutrient utilization and metabolism. The health consequences of abnormal liver function are widespread, many of which are not entirely understood. Recent advances in genomic biology, nanotechnology, computer science and related fields have supplied researchers with a powerful set of tools for the laboratory and clinic. Because nutrient status has been proven to be an important factor in health and disease, the use of these tools to identify nutrient–gene interactions and their association with disease has greatly increased over the past decade. Given its great importance to intermediary metabolism, the liver has been one of the primary organs of focus in recent nutrigenomic experiments. This paper will provide a brief synopsis of the recent technological advancements that may be applied to nutrition research, common mechanisms by which nutrients and genes interact with one another, a few examples pertaining to hepatic function, and future directions in the field.
Liver lipid metabolism
Authors: Nguyen P. , Leray V. , Diez M. , Serisier S. , Bloc’h J. Le , Siliart B. , Dumon H. 
Published: May 2008

SummaryThe liver plays a key role in lipid metabolism. Depending on species it is, more or less, the hub of fatty acid synthesis and lipid circulation through lipoprotein synthesis. Eventually the accumulation of lipid droplets into the hepatocytes results in hepatic steatosis, which may develop as a consequence of multiple dysfunctions such as alterations in β‐oxidation, very low density lipoprotein secretion, and pathways involved in the synthesis of fatty acids. In addition an increased circulating pool of non‐esterified fatty acid may also to be a major determinant in the pathogenesis fatty liver disease. This review also focuses on transcription factors such as sterol‐regulatory‐element‐binding protein‐1c and peroxisome proliferator‐activated receptor alpha, which promote either hepatic fatty acid synthesis or oxidation.
Response of broiler finishers to diets containing graded levels of processed castor oil bean (Ricinus communis L) meal
Authors: Ani A. O. , Okorie A. U. 
Published: May 2008

SummaryA 4‐week feeding experiment was conducted to determine the effects of graded levels of dehulled and cooked castor oil bean (Ricinus communis L) meal on the performance of broiler finishers. Castor oil bean seeds were dehulled and detoxified by cooking in two stages at 100 °C for 50 min per cooking. Sixty 6‐week‐old broiler birds (Anak strain) were randomly divided into four groups of 15 birds each. The groups were fed four isocaloric (2.90 Mcal of metabolizable energy/kg) and isonitrogenous (21% crude protein) diets containing 0%, 10%, 15% and 20% dehulled and cooked castor oil bean meal (CBM) for 4 weeks. Results showed that there were significant (p < 0.05) differences among treatments in average daily feed intake, final body weight, average daily weight gain (ADWG), feed conversion ratio (FCR) and protein efficiency ratio (PER). Birds fed diets containing 0% and 10% CBM had significantly (p < 0.05) higher feed intake than birds on 15% and 20% CBM diets. The lowest feed intake was recorded at the 20% CBM inclusion level. The highest ADWG was observed in birds fed 0% CBM diet, but this was not significantly (p > 0.05) different from the ADWG of birds on 10% CBM diet. Birds fed diets containing10% and 15% levels of CBM had similar and non‐significant (p > 0.05) ADWG. Birds fed 20% CBM diet had the least (p < 0.05) ADWG. Birds fed 0%, 10% and 15% CBM diets had similar FCR and this was significantly (p < 0.05) lower and better than that of birds on 20% CBM diet. The least (p < 0.05) PER was observed in birds fed 20% CBM diet. Birds fed 20% CBM diet had significantly (p < 0.05) higher packed cell volume (PCV) than birds on 10% and 15% CBM diets. Birds fed 0%, 10% and 15% CBM diets had similar (p > 0.05) PCV values. Birds fed diets containing 0%, 10% and 15% levels of CBM had similar and significantly (p < 0.05) lower heamoglobin than birds fed 20% CBM diets. There were also significant (p < 0.05) differences among treatments in dry matter (DM), nitrogen, ether extract (EE) and nitrogen‐free extract (NFE) retention. Birds fed 0% CBM diet had significantly (p < 0.05) higher retention of DM, nitrogen and NFE than birds on 10%, 15% and 20% CBM diets. Birds fed 10% CBM diet had significantly (p < 0.05) higher DM, nitrogen and NFE retention than birds on 15% and 20% CBM diets. The lowest retention of DM, nitrogen and NFE was recorded at the 20% CBM inclusion level. Birds fed 0% CBM diet had significantly (p < 0.05) higher EE retention than birds on 15% and 20% CBM diets. The lowest EE retention was observed at the 20% CBM inclusion level. The results of the study indicate that up to 10% dehulled and cooked CBM can be included in broiler finisher rations for optimum performance.
Rumen fermentation and degradability in buffalo and cattle using the in vitro gas production technique
Authors: Calabrò S. , Moniello G. , Piccolo V. , Bovera F. , Infascelli F. , Tudisco R. , Cutrignelli M. I. 
Published: May 2008

SummaryAn in vitro trial was conducted to investigate the effect of different inoculum sources (buffalo vs. cattle) on rumen fermentation and degradability. Incubations were carried out using rumen fluid obtained from buffalo or cattle fed the same diet [60% grass hay and 40% concentrate; 18 kg dry matter (DM)/day]. The fermentation kinetics of eight feeds commonly used in ruminant nutrition (alfalfa hay, barley meal, beet pulp, corn meal and silage, ryegrass hay and silage and soya bean meal s.e.) were studied with the in vitro gas production technique and rumen fermentation parameters (substrate disappearance, pH and volatile fatty acids production) were determined after 120 h of incubation. The linear relationship indicates that the microbial metabolic pathways of the two inocula for all the substrates were qualitatively similar, albeit often quantitatively different. In this in vitro study, a significant influence of rumen inoculum (buffalo vs. cow) on fermentation and degradability of the examined substrates was found. The differences in buffalo and cattle rumen fermentation can be explained with a different microbial activity of the two ruminant species, because of different amount of microbial population or microbial population constituted by different species of bacteria and protozoa.
Mycobiota and aflatoxins in raw materials and pet food in Brazil
Authors: Campos S. G. , Cavaglieri L. R. , Fernández Juri M. G. , Dalcero A. M. , Krüger C. , Keller L. A. M. , Magnoli C.E. , Rosa C. A. R. 
Published: May 2008

SummaryCommercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65–89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100%Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.
NBT‐PABA test to assess efficiency and kinetics of substituted proteolytic enzyme action in pancreatic duct ligated minipigs*
Authors: Mößeler A. , Bergemann J. , Becker C. , Stemme K. , Gregory P. C. , Kamphues J. 
Published: May 2008

SummaryThe NBT‐PABA test is an established method for diagnosis of pancreatic exocrine insufficiency. In the present study the NBT‐PABA test was used to test and compare the efficacy of two multienzyme preparations (product A and B) differing in galenic preparation in minipigs in which pancreatic exocrine insufficiency (PEI) was induced by pancreatic duct ligation. Without enzyme substitution no distinct increase in PABA was found in blood after oral administration of NBT‐PABA. Administration of both enzyme preparations led to a clear dose dependent rise in PABA‐concentrations in blood. Interestingly, the two preparations showed different time curves of serum PABA concentration, indicating differences in the kinetic of proteolytic enzyme action. It is concluded that the NBT‐PABA test can be a very useful test for indirectly evaluating proteolytic enzyme efficacy in vivo, and also gives information about the kinetics of enzyme action, not only the end‐result of enzyme action (like digestibility trials which were used traditionally). A single test is performed in a few hours and there is no need for fistulated animals.