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This study aims to confirm the “vegetable-first” effect. In addition, because we aimed dietary fiber in vegetable salad, the effect after the ingestion of vegetable salad extract (vegetable salad from which solids have been removed) before carbohydrates on postprandial serum glucose level was also evaluated. A total of 13 healthy men were given meals after one-night of fasting: rice–vegetable salad, vegetable salad–rice, and vegetable salad extract–rice. Blood samples were taken at 0, 30, 45, 60, 90, and 120 min after the ingestion of the test meal to measure serum glucose levels. Serum glucose levels were significantly lower after 45 and 60 min in the vegetable salad–rice group compared to the rice–vegetable salad group. No significant difference was found between the vegetable salad extract–rice group and the vegetable salad–rice/rice–vegetable salad group. The result suggested that it might be important to ingest vegetables to obtain the “vegetable-first” effect. [ABSTRACT FROM AUTHOR]

The ability of bison to thrive on grass and forage-based diets is of great interest for the bison industry. However, raising bison on pasture presents challenges, including longer finishing times. While some producers overcome this by feeding grain or concentrate to bison, this practice conflicts with the concept of natural production. Considering that bison maintain better on feed of poor quality compared with domesticated grazers, it can be inferred that there is great potential for improving their productivity on pastures. Because ruminants rely on symbiotic microorganisms to break down and ferment plant polysaccharides into nutrients they can absorb and assimilate, the metabolic capabilities of rumen microbial communities in bison would likely have an important role in contributing to the efficiency of their host. To gain further insight, we investigated the ruminal metagenome of six grass-fed bison. Raw sequence reads generated using an Illumina Miseq (2x250) platform from ruminal microbial genomic DNA were assembled into genomic contigs using custom written Perl scripts. A total of 6,297 contigs, representing a combined total length of 23,822,104 nucleotides, were obtained for all samples. Coding sequences were identified and annotated using RAST (Rapid Annotation using Subsystem Technology), which was followed by assignment to metabolic pathways using references from KEGG (Kyoto Encyclopedia of Genes and Genomes), with a particular focus on carbohydrate metabolism and amino acid synthesis. This analysis resulted in the identification of nine of the ten enzymes necessary for glycolysis, indicating the capacity to metabolize glucose into pyruvate. Two outcomes were predicted for pyruvate: conversion to lactate through lactate dehydrogenases (EC 1.1.1.27, EC 1.1.1.28), as well as the production of acetate through the sequential activity of pyruvate-flavodoxin oxidoreductase (EC 1.2.7.1), phosphate acetyltransferase (EC 2.3.1.8), and acetate kinase (EC 2.7.2.1). Propionate and butyrate were also predicted as end-products being produced in bison rumen, as well as synthesis of precursors for aromatic amino synthesis through the Chorismate-Shikimate pathway. In addition, enzymes involved in the fermentation of five-carbon sugars, such as arabinose (EC 5.1.3.4, EC 2.7.1.16, and EC 5.3.1.4) and xylose (EC 2.7.1.17 and EC 5.3.1.5), were also identified. Characterization of the metabolic potential of ruminal bacteria from pasture-fed bison, such as the utilization of glucose and pentose sugars that form the backbone of structural polysaccharides to produce short chain fatty acids and essential amino acids, will provide further insight on the use of forage and grassbased diets by these animals. [ABSTRACT FROM AUTHOR]

Congeneric species often share ecological niche space resulting in competitive interactions that either limit co-occurrence or lead to niche partitioning. Differences in fundamental nutritional niches mediated through character displacement or isolation during evolution are potential mechanisms that could explain overlapping distribution patterns of congenerics. We directly compared nutritional requirements and tolerances that influence the fundamental niche of mule (Odocoileus hemionus) and white-tailed deer (O. virginianus), which occur in allopatry and sympatry in similar realized ecological niches across their ranges in North America. Digestible energy and protein requirements and tolerances for plant fiber and plant secondary metabolites (PSMs) of both deer species were quantified using in vivo digestion and intake tolerance trials with six diets ranging in content of fiber, protein, and PSMs using tractable deer raised under identical conditions in captivity. We found that compared with white-tailed deer, mule deer required 54% less digestible protein and 21% less digestible energy intake per day to maintain body mass and nitrogen balance. In addition, they had higher fiber, energy, and dry matter digestibility and produced glucuronic acid (a byproduct of PSM detoxification) at a slower rate when consuming the monoterpene α-pinene. The mule deers' enhanced physiological abilities to cope with low-quality, chemically defended forages relative to white-tailed deer might minimize potential competitive interactions in shared landscapes and provide a modest advantage to mule deer in habitats dominated by low-quality forages. [ABSTRACT FROM AUTHOR]

Context: Dietary fiber intake may relate to bone health.Objective: To investigate whether dietary fiber intake is associated with bone mineral density (BMD), and the modification effect of genetic variations related to gut microbiota-derived short-chain fatty acids (SCFAs).Design: The associations of dietary fiber intake with estimated BMD derived from heel ultrasound and fractures were assessed in 224 630 and 384 134 participants from the UK Biobank.Setting: UK Biobank.Main Outcome Measures: Estimated BMD derived from heel ultrasound.Results: Higher dietary fiber intake (per standard deviation) was significantly associated with higher heel-BMD (β [standard error] = 0.0047 [0.0003], P = 1.10 × 10-54). Similarly significant associations were observed for all the fiber subtypes including cereal, fruit (dried and raw), and vegetable (cooked and raw) (all P < .05). A positive association was found in both women and men but more marked among men except for dietary fiber in cooked vegetables (all Pinteraction < .05). A protective association was found between dietary fiber intake and hip fracture (hazard ratio, 95% confidence interval: 0.94, 0.89-0.99; P = 3.0 × 10-2). In addition, the association between dietary fiber and heel BMD was modified by genetically determined SCFA propionate production (Pinteraction = 5.1 × 10-3). The protective association between dietary fiber and heel BMD was more pronounced among participants with lower genetically determined propionate production.Conclusions: Our results indicate that greater intakes of total dietary fiber and subtypes from various food sources are associated with higher heel-BMD. Participants with lower genetically determined propionate production may benefit more from taking more dietary fiber. [ABSTRACT FROM AUTHOR]

Gastrointestinal stromal tumors (GISTs) are tumors arising from the fourth layer of the stomach. They are the most common form of mesenchymal neoplasms in the gastrointestinal tract. The diagnosis for the aforementioned tumors is made through endoscopic ultrasonography (EUS) with no further inspection through biopsies and aspirations. Regarding the fact that biopsies are not made in these cases, pathological misdiagnoses, however rare and effectless in the final outcome of the surgery, do occur. Here, we present a case of a 35-year-old male diagnosed with GIST through the means of EUS however, the post-op pathology report showed something very interesting. This patient was reported to be a case of perforated peptic ulcer and we found vegetable fiber component in the tissue of this patient. Bearing in mind the finding, misdiagnoses of GIST patients are probable, and careful planning prior to the surgery is recommended. [ABSTRACT FROM AUTHOR]

The herbivore rumen ecosystem constitutes an extremely efficient degradation machinery for the intricate chemical structure of fiber biomass, thus, enabling the hosting animal to digest its feed. The challenging task of deconstructing and metabolizing fiber is performed by microorganisms inhabiting the rumen. Since most of the ingested feed is comprised of plant fiber, these fiber-degrading microorganisms are of cardinal importance to the ecology of the rumen microbial community and to the hosting animal, and have a great impact on our environment and food sustainability. We summarize herein the enzymological fundamentals of fiber degradation, how the genes encoding these enzymes are spread across fiber-degrading microbes, and these microbes' interactions with other members of the rumen microbial community and potential effect on community structure. An understanding of these concepts has applied value for agriculture and our environment, and will also contribute to a better understanding of microbial ecology and evolution in anaerobic ecosystems. [ABSTRACT FROM AUTHOR]

The identification of trees as a source for fibers in textiles and cordage from these Stone Age artifacts at Çatalhöyük is significant. The perforations of the vessels seen in the ancient fibers provided proof that the fibers were not from flax but were consistent with oak bast [Figure 1]. [Extracted from the article]

Aims The optimization of a simple protocol for the mass production of viable microsclerotia (MS) of Verticillium spp., even for recalcitrant isolates, to the inoculation of olive cuttings. Method and Results Four Verticillium spp. isolates were characterized by growth rate and morphology. Then, the production ability and the viability of MS over time were assessed in seven solid culture media and five aqueous media. The best culture medium, according to the quantity and the quality (size) of the MS produced, was the alkaline-modified sodium polipectate (AMSP) aqueous medium. The MS viability was higher in peat moss substrates. Finally, the MS obtained in this work were infective causing 100% incidence of Verticillium wilt (VW) disease in inoculated olive plants. Conclusion This study demonstrates that the modified sodium polipectate medium amended with 0·1% agar is the most suitable for the production of MS of Verticillium dahliae isolates that have lost the ability to produce MS in standard culture media. Significance and Impact of the Study Mass production of MS for artificial infestation of soil is critical to the study of epidemiological and control aspects of the VW. To overcome the failure in the production of MS in recalcitrant isolates, a culture media was optimized and a successful plant inoculation experiment was carried out with artificial MS. [ABSTRACT FROM AUTHOR]

The objective of this study was to reveal the potential of using Fourier transform mid-infrared (FTIR) and near infrared (NIR) spectroscopy as tools for the determination of indigestible neutral (NDF) fraction (iNDF) of barley plant silage. A total of 48 barley plant silage samples collected from different farms in Western Canada provinces were analyzed for iNDF. Reference values were matched with NIR and FTIR spectra. Spectral data processing (pretreatments) included first derivative (FD), standard normal variate (SNV), multiplicative scattering correction (MSC), second derivative (SD) and orthogonal signal correction (OSC). Prediction equations were obtained from each model using an external validation set. The determination coefficient of external validation (R2 P) of iNDF was 0.62 for FTIR, while 0.41 for NIR and the corresponding ratio performance deviation (RPD) were 1.69 and 1.38 in FTIR and NIR, respectively. Results from this research showed the high potential of applying infrared molecular spectroscopy for the examination of forage plant fiber digestibility. More studies are needed to improve the accuracy and performance of FTIR and NIR spectroscopies in predicting the iNDF of barley plant silage samples. [ABSTRACT FROM AUTHOR]

Feeding behaviors of the redbanded stink bug, Piezodorus guildinii (Westwood), on vegetative (stem and leaflet) and reproductive (pod) tissues of soybean, Glycine max (L.), were recorded using an AC-DC electropenetrograph (EPG) apparatus. Eight different probing waveforms were characterized and defined: Pg1a, Pg1b, Pg1c, Pg1d, Pg2, Pg3a, Pg3b, and Pg4 grouped into three different families, P, I, and N. Histological studies of intact stylets within salivary sheaths observed during Pg1b, Pg1c, Pg2, and Pg3 waveforms were correlated with the specific penetration sites. Waveforms Pg1a, Pg1b, Pg1c, and Pg1d (pathway—family P) occurred at the start of probing activities and represent stylet penetration deep into plant tissue. Waveforms Pg2, Pg3a, and Pg3b (family I) represent the food ingestion phase. Pg2 waveform represents xylem sap ingestion primarily on leaves and stems. During Pg3a, stylets were moving, lacerating deeply into pod tissue and partially retracting; during Pg3b, stylets were motionless inside the pod tissue. Pg3b occurred interspersed with waveform Pg3a. Waveform Pg4 (family N) represented short interruptions that occurred within waveform Pg2. The study demonstrated that P. guildinii uses the cell rupture strategy to ingest from endosperm in soybean pod, and the same insect could switch to salivary sheath feeding to ingest from xylem in soybean leaves and stems. This unusual behavior explains symptoms of stink bug damage to soybean. The P. guildinii waveforms defined herein will allow future EPG studies to aid in development of soybean varieties that resist the feeding and damage caused by this and other stink bug pests. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) have important roles in gene regulation during plant development. Previous studies revealed that some miRNAs are highly shared by most land plants. Recently, the liverwort, Marchantia polymorpha, has been studied by molecular genetic approaches, and sequencing of its genome is currently underway. The expression pattern and the detailed functions ofmiRNAs during Marchantia development are unknown. Here, we profiled the small RNAs expressed in thalli, antheridiophores and archegoniophores of M. polymorpha using high-throughput RNA sequencing. We revealed that a limited number of miRNAs are shared between M. polymorpha and the moss, Physcomitrella patens, and that a number of miRNAs are M. polymorpha specific. Like other land plants, cognate target genes corresponding to conserved miRNAs could be found in the genome database and were experimentally confirmed to guide cleavage of target mRNAs. The results suggested that two genes in the SPL (SQUAMOSA PROMOTER BINDING-LIKE) transcription factor family, which are regulated by miR156 in most land plants, were instead targeted by two distinct miRNAs in M. polymorpha. In order to demonstrate the physiological roles of miRNAs in M. polymorpha, we constructed an miRNA ectopic expression system to establish overexpression transformants for conserved miRNAs, miR166 and miR319. Ectopic expression of these miRNAs induced abnormal development of the thallus and gemma cups, suggesting that balanced expression of miRNA/target mRNAs has a crucial role in developmental regulation in M. polymorpha. Profiling data on miRNA together with the ectopic expression system would provide new information on the liverwort small RNA world and evolutionary divergence/ conservation of small RNA function among land plants. [ABSTRACT FROM AUTHOR]

Contractile cell walls are found in various plant organs and tissues such as tendrils, contractile roots, and tension wood. The tension-generating mechanism is not known but is thought to involve special cell wall architecture. We previously postulated that tension could result from the entrapment of certain matrix polymers within cellulose microfibrils. As reported here, this hypothesis was corroborated by sequential extraction and analysis of cell wall polymers that are retained by cellulose microfibrils in tension wood and normal wood of hybrid aspen (Populus tremula 3 Populus tremuloides). b-(1?4)-Galactan and type II arabinogalactan were the main large matrix polymers retained by cellulose microfibrils that were specifically found in tension wood. Xyloglucan was detected mostly in oligomeric form in the alkali-labile fraction and was enriched in tension wood. b-(1?4)-Galactan and rhamnogalacturonan I backbone epitopes were localized in the gelatinous cell wall layer. Type II arabinogalactans retained by cellulose microfibrils had a higher content of (methyl)glucuronic acid and galactose in tension wood than in normal wood. Thus, b-(1?4)-galactan and a specialized form of type II arabinogalactan are trapped by cellulose microfibrils specifically in tension wood and, thus, are the main candidate polymers for the generation of tensional stresses by the entrapment mechanism. We also found high b-galactosidase activity accompanying tension wood differentiation and propose a testable hypothesis that such activity might regulate galactan entrapment and, thus, mechanical properties of cell walls in tension wood. [ABSTRACT FROM AUTHOR]

Willows (Salix spp.) are important as a potential feedstock for bioenergy and biofuels. Previous work suggested that reaction wood (RW) formation could be a desirable trait for biofuel production in willows as it is associated with increased glucose yields, but willow RW has not been characterized for cell wall components. Fasciclin-like arabinogalactan (FLA) proteins are highly up-regulated in RW of poplars and are considered to be involved in cell adhesion and cellulose biosynthesis. COBRA genes are involved in anisotropic cell expansion by modulating the orientation of cellulose microfibril deposition. This study determined the temporal and spatial deposition of non-cellulosic polysaccharides in cell walls of the tension wood (TW) component of willow RW and compared it with opposite wood (OW) and normal wood (NW) using specific antibodies and confocal laser scanning microscopy and transmission electron microscopy. In addition, the expression patterns of an FLA gene (SxFLA12) and a COBRA-like gene (SxCOBL4) were compared using RNA in situ hybridization. Deposition of the non-cellulosic polysaccharides (1-4)-β-D-galactan, mannan and de-esterified homogalacturonan was found to be highly associated with TW, often with the G-layer itself. Of particular interest was that the G-layer itself can be highly enriched in (1-4)-β-D-galactan, especially in G-fibres where the G-layer is still thickening, which contrasts with previous studies in poplar. Only xylan showed a similar distribution in TW, OW, and NW, being restricted to the secondary cell wall layers. SxFLA12 and SxCOBL4 transcripts were specifically expressed in developing TW, confirming their importance. A model of polysaccharides distribution in developing willow G-fibre cells is presented. [ABSTRACT FROM AUTHOR]

This review considers how the hydroxyl radical (OH•) may be generated in vivo, and how it plays a part in the life and death of a plant.The hydroxyl radical (OH•) is the most potent yet short-lived of the reactive oxygen species (ROS) radicals. Just as hydrogen peroxide was once considered to be simply a deleterious by-product of oxidative metabolism but is now acknowledged to have signalling roles in plant cells, so evidence is mounting for the hydroxyl radical as being more than merely an agent of destruction. Its oxidative power is harnessed to facilitate germination, growth, stomatal closure, reproduction, the immune response, and adaptation to stress. It features in plant cell death and is a key tool in microbial degradation of plant matter for recycling. Production of the hydroxyl radical in the wall, at the plasma membrane, and intracellularly is facilitated by a range of peroxidases, superoxide dismutases, NADPH oxidases, and transition metal catalysts. The spatio-temporal activity of these must be tightly regulated to target substrates precisely to the site of radical production, both to prevent damage and to accommodate the short half life and diffusive capacity of the hydroxyl radical. Whilst research has focussed mainly on the hydroxyl radical’s mode of action in wall loosening, studies now extend to elucidating which proteins are targets in signalling systems. Despite the difficulties in detecting and manipulating this ROS, there is sufficient evidence now to acknowledge the hydroxyl radical as a potent regulator in plant cell biology. [ABSTRACT FROM AUTHOR]

Pigs may display biting behavior directed at pen mates, resulting in body damage such as tail wounds. We assessed the suitability of jute sacks (hung vertically at wall) to reduce biting behaviors and tail wounds in rearing gilts. Additionally, we assessed several characteristics of different types of tail biters. Tail docked rearing gilts originated from 72 litters, which were kept in partly slatted pens with jute sacks (J) or barren control pens (CON; 36 litters per treatment). Tail and ear damage were observed at weaning (4 wk) and during the weaner and rearing phase (17 J and 19 CON pens). Sow (dam) damage was also considered. Biting behaviors (tail, ear, and other) were observed during the weaner and rearing phase. Weight was recorded at birth, weaning, and end of the weaner phase and ADG was calculated from birth till weaning and from weaning till 9 wk. Furthermore, estimated breeding values for litter size, litter birth weight, back fat, and growth between birth and ~105 kg, and ~25 to 105 kg were determined. Jute sacks reduced tail and ear damage at weaning (both P < 0.001) and tended to reduce sow tail damage (P = 0.09). Jute sacks also reduced tail damage post-weaning (P < 0.001 to 0.03), with a 5-fold reduction of (mild) tail wounds at the age of 13 wk. Biting behaviors directed at pen mates were up to 50% lower in J pens (P < 0.001 to 0.04). Higher genotypic litter size, litter birth weight, growth, and lower back fat seemed associated with higher levels of ear or tail-biting behavior (P = 0.002 to 0.09), albeit dependent on treatment and phase. Higher phenotypic litter sizes were associated with higher levels of biting behaviors (P = 0.004-0.08). High-tail-biters and Medium-tail-biters (the latter less pronounced) stemmed from larger litters (P = 0.01 to 0.05), were heavier (P = 0.03 to 0.04), grew faster (P = 0.05 to 0.08), and displayed higher levels of all kinds of biting behavior directed to pen mates and the jute sack (P < 0.001 to 0.10) compared with non-tail-biters, the effect size dependent on treatment and phase of life. To conclude, jute sacks may profoundly reduce damaging behaviors and tail wounds in rearing gilts, probably because they partly meet the behavioral need of pigs for rooting and chewing. Furthermore, (tail) biting is associated with production level of the gilts (phenotypically and genetically), which suggests a role for breeding programs and additional research focusing on metabolic demands of (tail) biting pigs. [ABSTRACT FROM AUTHOR]

Objective: To compare the degree of small bowel distension achieved by 3% sorbitol, a high osmolarity solution, and a psyllium-based bulk fibre as oral contrast agents (OCAs) in MR enterography (MRE). Methods: This retrospective study was approved by our institutional review board. A total of 45 consecutive normal MRE examinations (sorbitol, n = 20; psyllium, n = 25) were reviewed. The patients received either 1.51 of 3% sorbitol or 21 of 1.6 g kg-1 psyllium prior to imaging. Quantitative small bowel distension measurements were taken in five segments: proximal jejunum, distal jejunum, proximal ileum, distal ileum and terminal ileum by two independent radiologists. Distension in these five segments was also qualitatively graded from 0 (very poor) to 4 (excellent) by two additional independent radiologists. Statistical analysis comparing the groups and assessing agreement included intraclass coefficients, Student's f-test and Mann-Whitney U-test. Results: Small bowel distension was not significantly different in any of the five small bowel segments between the use of sorbitol and psyllium as OCAs in both the qualitative (p = 0.338-0.908) and quantitative assessments (p = 0.083-0.856). The mean bowel distension achieved was 20.1 ±2.2 mm for sorbitol and 19.8 ±2.5 mm for psyllium (p = 0.722). Visualization of the ileum was good or excellent in 65% of the examinations in both groups. Conclusion: Sorbitol and psyllium are not significantly different at distending the small bowel and both may be used as OCAs for MRE studies. Advances in knowledge: This is the first study to directly compare the degree of distension in MRE between these two common, readily available and inexpensive OCAs. [ABSTRACT FROM AUTHOR]

Dimorphic fibres in angiosperm woods are designated when zones of two different kinds of fibres can be distinguished in transverse sections. The usage of most authors contrasts wider, thinner-walled, shorter (sometimes storied) fibres with narrower, thicker-walled fibres that have narrower lumina. The wider fibres can be distinguished in longitudinal sections from axial parenchyma, which usually consists of strands of two or more cells each surrounded by secondary walls (and thus different from septate fibres). This phenomenon occurs in some Araliaceae, Asteraceae, Fabaceae, Myrtales (notably Lythraceae), Sapindales (especially Sapindaceae), Urticales and even some Gnetales. Additional instances can doubtless be found, especially if instances of wide latewood fibres together with narrow earlywood fibres are included. There is little physiological evidence on differential functions of dimorphic fibres, except in Acer, in which hydrolysis of starch in the wide fibres is known to result in transfer of sugar into vessels early in the growing season. Starch storage in axial parenchyma may, in a complementary way, serve for embolism reversal and prevention and thus for maintenance of the water columns. Crystalliferous fibres ( Myrtales, Sapindales) can be considered a form of fibre dimorphism that deters predation. Gelatinous fibres, often equated with tension wood, can also be considered as a form of fibre dimorphism. The evolutionary significance of fibre dimorphism is that a few small changes in fibre structure can result in the accomplishment of diversified functions. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174, 44-67. [ABSTRACT FROM AUTHOR]

The highly elongated single-celled cotton fibre consists of lint and fuzz, similar to the Arabidopsis trichome. Endoreduplication is an important determinant in Arabidopsis trichome initiation and morphogenesis. Fibre development is also controlled by functional homologues of Arabidopsis trichome patterning genes, although fibre cells do not have a branched shape like trichomes. The identification and characterization of the homologues of 10 key Arabidopsis trichome branching genes in Gossypium arboreum are reported here. Nuclear ploidy of fibres was determined, and gene function in cotton callus and fibre cells was investigated. The results revealed that the nuclear DNA content was constant in fuzz, whereas a limited and reversible change occurred in lint after initiation. Gossypeum arboreum BRANCHLESS TRICHOMES (GaBLT) was not transcribed in fibres. The homologue of STICHEL (STI), which is essential for trichome branching, was a pseudogene in Gossypium. Targeted expression of GaBLT, Arabidopsis STI, and the cytokinesis-repressing GaSIAMESE in G. hirsutum fibre cells cultured in vitro resulted in branching. The findings suggest that the distinctive developmental mechanism of cotton fibres does not depend on endoreduplication. This important component may be a relic function that can be activated in fibre cells. [ABSTRACT FROM AUTHOR]

The cotton fleahopper, Pseudatomoscelis seriatus (Reuter) (Hemiptera: Miridae) is an economically important insect pest of cotton in the United States. However, reports of cotton fleahopper infestation and its management in cotton fields are restricted primarily to Texas, Oklahoma, and Arkansas. The objective of this study was to understand the genetic diversity of cotton fleahopper populations infesting cotton in the cotton-growing areas of the United States. Amplified fragment length polymorphism markers were used to detect genetic diversity and to characterize geographic genotypes across the distribution of the cotton fleahopper in the United States. We used 172 individuals and 559 amplified fragment length polymorphism loci in this study and found significant, but low, level of genetic differentiation among geographic populations (FST = 0.02; P < 0.0001). Molecular fingerprints of cotton fleahopper populations were partitioned into three broad regional genetic populations with a western, central, and eastern distribution. The western (Arizona) and eastern (Florida, Georgia, South Carolina, and North Carolina) populations are genetically distinct, whereas the central (Texas, Oklahoma, Arkansas, Mississippi, Louisiana, and Alabama) population represents an admixed population, which include both western and eastern populations. These results suggest considerable gene flow among the populations within regions but restricted gene flow among populations from eastern and western region. [ABSTRACT FROM AUTHOR]

Background and Aims Elucidation of the mechanisms by which plants adapt to elevated CO2 is needed; however, most studies of the mechanisms investigated the response of plants adapted to current atmospheric CO2. The rapid respiration rate of cotton (Gossypium hirsutum) fruits (bolls) produces a concentrated CO2 microenvironment around the bolls and bracts. It has been observed that the intercellular CO2 concentration of a whole fruit (bract and boll) ranges from 500 to 1300 µmol mol−1 depending on the irradiance, even in ambient air. Arguably, this CO2 microenvironment has existed for at least 1·1 million years since the appearance of tetraploid cotton. Therefore, it was hypothesized that the mechanisms by which cotton bracts have adapted to elevated CO2 will indicate how plants will adapt to future increased atmospheric CO2 concentration. Specifically, it is hypothesized that with elevated CO2 the capacity to regenerate ribulose-1,5-bisphosphate (RuBP) will increase relative to RuBP carboxylation. Methods To test this hypothesis, the morphological and physiological traits of bracts and leaves of cotton were measured, including stomatal density, gas exchange and protein contents. Key results Compared with leaves, bracts showed significantly lower stomatal conductance which resulted in a significantly higher water use efficiency. Both gas exchange and protein content showed a significantly greater RuBP regeneration/RuBP carboxylation capacity ratio (Jmax/Vcmax) in bracts than in leaves. Conclusions These results agree with the theoretical prediction that adaptation of photosynthesis to elevated CO2 requires increased RuBP regeneration. Cotton bracts are readily available material for studying adaption to elevated CO2. [ABSTRACT FROM AUTHOR]

Reindeer digestion is impossible without the symbiotic microorganisms that live in its rumen. The composition of plant fibers present in the diet of reindeer is characterized by an increased content of plant fiber, hemicellulose, lignin, and secondary lichen metabolites. The Arctic is characterized by extremely scarce food resources even in summer. In winter the nutritional value of the diet is further reduced. The digestion of such feeds is provided only by the enzyme systems of microorganisms that live in the rumen of ruminants. Therefore, the purpose of our study was to determine the changes occurring in the composition of the reindeer' rumen bacterial community inhabiting the Nenets region of the Russian Arctic. Rumen contents were collected from 20 reindeer in winter and summer 2017. To identify the bacterial community, 16S rRNA sequencing was used on the MiSeq (Illumina). Statistical processing of the results of NGS using the PERMANOVA analysis showed that the rumen bacterial communities in winter and summer have significant differences (P = 0.001). Taxonomic analysis using the GreenGenes database showed that, in general, at the phylum level in the community, representatives of Firmicutes (29.98-52.67%) and Bacteroidetes (33.55-51.87%) dominated. Significant differences were shown for microorganisms associated with the fermentation of plant polysaccharides. In winter, a significant increase in bacteria of the genera Succiniclasticum (P < 0.001), Paraprevotellaceae (P < 0.001), Coprococcus (P < 0.001), Butyrivibrio (P < 0.001), Prevotella (P < 0.001), Ruminococcus (P < 0.001). Thus, there is a succession of the bacterial community of the reindeer rumen associated with the change of seasons, affecting minor groups of microorganisms. In turn, it is associated with the availability of various components of the diet and the predominance of more or less easily digestible substances in it. The study was supported by a grant of Russian Science Foundation Project No. 17-76-20026. [ABSTRACT FROM AUTHOR]

The microbial communities associated with kenaf ( Hibiscus cannabinus) plant fibers during retting were determined in an effort to identify possible means of accelerating this process for industrial scale-up. Microbial communities were identified by semiconductor sequencing of 16S rRNA gene amplicons from DNA harvested from plant-surface associated samples and analyzed using an Ion Torrent PGM. The communities were sampled after 96 h from each of three different conditions, including amendments with pond water, sterilized pond water, or with a mixture of pectinolytic bacterial isolates. Additionally, plants from two different sources and having different pretreatment conditions were compared. We report that the best retting communities are dominated by members of the order Clostridiales. These bacteria appear to be naturally associated with the plant material, although slight variations between source materials were found. Additionally, heavy inoculations of pectinolytic bacteria established themselves and in addition their presence facilitated the rapid dominance of the original plant-associated Clostridiales. These data suggest that members of the order Clostridiales dominate the community and are most closely associated with efficient and effective retting. The results further suggest that establishment of the community structure is first driven by the switch to anaerobic conditions, and subsequently by possible competition for nitrogen. These findings reveal important bacterial groups involved in fiber retting, and suggest mechanisms for the manipulation of the community and retting efficiency by modifying nutrient availability. [ABSTRACT FROM AUTHOR]

Fibre properties and the biochemical composition of cell walls are important traits in many applications. For example, the lengths of fibres define the strength and quality of paper, and lignin content is a critical parameter for the use of biomass in biofuel production. Identifying genes controlling these traits is comparatively difficult in woody species, because of long generation times and limited amenability to high-resolution genetic mapping. To address this problem, this study mapped quantitative trait loci (QTLs) defining fibre length and lignin content in the Arabidopsis recombinant inbred line population Col-4×Ler-0. Adapting high-throughput phenotyping techniques for both traits for measurements in Arabidopsis inflorescence stems identified significant QTLs for fibre length on chromosomes 2 and 5, as well as one significant QTL affecting lignin content on chromosome 2. For fibre length, total variation within the population was 208% higher than between parental lines and the identified QTLs explained 50.58% of the observed variation. For lignin content, the values were 261 and 26.51%, respectively. Bioinformatics analysis of the associated intervals identified a number of candidate genes for fibre length and lignin content. This study demonstrates that molecular mapping of QTLs pertaining to wood and fibre properties is possible in Arabidopsis, which substantially broadens the use of Arabidopsis as a model species for the functional characterization of plant genes. [ABSTRACT FROM AUTHOR]

Background and Aims Although tension wood formation and the structure of gelatinous fibres (G-fibres) have been widely investigated, studies of the influence of the reaction phenomenon on phloem fibres have been few and incomplete in comparison with those of xylem wood fibres. This study was undertaken to clarify the influence of stem inclination on phloem fibres using several Japanese hardwood species that produce different G-fibre types in tension wood. Methods Eight hardwood species were inclined at 30–45° at the beginning of April. Specimens were collected in July and December. The cell-wall structure and lignin distribution of phloem fibres on both the tension and opposite sides were compared by light microscopy, ultraviolet microscopy, confocal laser scanning microscopy after staining with acriflavine, and transmission electron microscopy after staining with potassium permanganate. Key Results Three types of changes were found in tension-side phloem fibres: (1) increases in the proportion of the syringyl unit in lignin in the S1 and S2 layers and compound middle lamella (Cercidiphyllum japonicum), (2) formation of unlignified gelatinous layers (Melia azedarach and Acer rufinerve) and (3) increases in the number of layers (n) in the multi-layered structure of S1 + S2 + n (G + L) (Mallotus japonicus). Other species showed no obvious change in cell-wall structure or lignin distribution. Conclusions Phloem fibres of the tree species examined in our study showed three types of changes in lignin distribution and cell-wall structure. The reaction phenomenon may vary with tree species and may not be closely related to G-fibre type in tension wood. [ABSTRACT FROM AUTHOR]

Lygus hesperus Knight (Hemiptera: Miridae) is a key pest of cotton (Gossypium spp.) in the western United States that injures floral buds (squares) and developing fruit (bolls). However, no clear relationship between Lygus population level and plant injury has been established. Age-dependent feeding activity by L. hesperus is a possible source of variation that has not been examined for its influence in studies of the impact of Lygus on cotton. Recent video-based laboratory studies indicated that feeding behaviors and trivial movement varied among L. hesperus adults of different gender and reproductive states (prereproductive; reproductive and unmated; and reproductive and mated). We compared within-plant distributions and accumulations of feeding injury to intact cotton plants corresponding to adult L. hesperus of different gender and reproductive states. Adult females, regardless of reproductive state, were observed on squares and axillary buds more often than were males. Additionally, prereproductive adults were observed on squares and axillary buds more often than were mated or unmated reproductive adults, regardless of gender. Plants that were exposed to prereproductive adults exhibited more abscised squares and more squares with injured anthers compared with plants exposed to reproductive adults. However, feeding injury did not differ by insect mating status or gender. These results are consistent with results of our previous video-based assays, and indicate adult reproductive state represents a source of variation that should be controlled in studies to evaluate Lygus-induced injury to cotton and other crop plants. [ABSTRACT FROM AUTHOR]

Runnability problems caused by suspended bacteria in water using industries, have, in contrast to biofilms, received little attention. We describe here that Pseudoxanthomonas taiwanensis, a wide-spread and abundant bacterium in paper machine water circuits, aggregated dispersions of wood extractives ("pitch") and resin acid, under conditions prevailing in machine water circuits (10 cfu ml, pH 8, 45°C). The aggregates were large enough (up to 50 μm) so that they could be expected to clog wires and felts and to reduce dewatering of the fiber web. The Pseudoxanthomonas bacteria were negatively charged over a pH range of 3.2-10. Cationic polyelectrolytes of the types used as retention aids or fixatives to flocculate "anionic trash" in paper machines were effective in flocculating the Pseudoxanthomonas bacteria. The polyelectrolyte most effective for this purpose was of high molecular weight (7-8 × 10 g mol) and low charge density (1 meq g), whereas polyelectrolytes that effectively zeroed the electrophoretic mobility (i.e., neutralized the negative charge) of the bacterium were less effective in flocculating the bacteria. Based on the results, we concluded that the polyelectrolytes functioning by bridging mechanism, rather than by neutralization of the negative charge, may be useful as tools for reducing harmful deposits resulting from interaction of bacteria with wood extractives in warm water industry. [ABSTRACT FROM AUTHOR]

Seeds provide food, feed, fiber and fuel. They are also an important delivery system of genetic information, which is essential for the survival of wild species in ecosystems and the production of agricultural crops. In this review, seed traits and genes that are potentially important for agricultural applications are discussed. Over the long period of crop domestication, seed traits have been modified through intentional or unintentional selections. While most selections have led to seed traits favorable for agricultural consumption, such as larger seeds with higher nutritional value than the wild type, other manipulations in modern breeding sometimes led to negative traits, such as vivipary, precocious germination on the maternal plant or reduced seed vigor, as a side effect during the improvement of other characteristics. Greater effort is needed to overcome these problems that have emerged as a consequence of crop improvement. Seed biology researchers have characterized the function of many genes in the last decade, including those associated with seed domestication, which may be useful in addressing critical issues in modern agriculture, such as the prevention of vivipary and seed shattering or the enhancement of yields. Recent discoveries in seed biology research are highlighted in this review, with an emphasis on their potential for translational biology. [ABSTRACT FROM AUTHOR]

The incompatible pathosystem between resistant cotton (Gossypium barbadense cv. 7124) and Verticillium dahliae strain V991 was used to study the cotton transcriptome changes after pathogen inoculation by RNA-Seq. Of 32 774 genes detected by mapping the tags to assembly cotton contigs, 3442 defence-responsive genes were identified. Gene cluster analyses and functional assignments of differentially expressed genes indicated a significant transcriptional complexity. Quantitative real-time PCR (qPCR) was performed on selected genes with different expression levels and functional assignments to demonstrate the utility of RNA-Seq for gene expression profiles during the cotton defence response. Detailed elucidation of responses of leucine-rich repeat receptor-like kinases (LRR-RLKs), phytohormone signalling-related genes, and transcription factors described the interplay of signals that allowed the plant to fine-tune defence responses. On the basis of global gene regulation of phenylpropanoid metabolism-related genes, phenylpropanoid metabolism was deduced to be involved in the cotton defence response. A closer look at the expression of these genes, enzyme activity, and lignin levels revealed differences between resistant and susceptible cotton plants. Both types of plants showed an increased level of expression of lignin synthesis-related genes and increased phenylalanine-ammonia lyase (PAL) and peroxidase (POD) enzyme activity after inoculation with V. dahliae, but the increase was greater and faster in the resistant line. Histochemical analysis of lignin revealed that the resistant cotton not only retains its vascular structure, but also accumulates high levels of lignin. Furthermore, quantitative analysis demonstrated increased lignification and cross-linking of lignin in resistant cotton stems. Overall, a critical role for lignin was believed to contribute to the resistance of cotton to disease. [ABSTRACT FROM PUBLISHER]

In woody plants, pioneer roots are the main roots used to expand the root system horizontally and vertically whereas fibrous ‘feeder’ roots are chiefly used in the absorption of water and nutrients. Because of their different roles, we expected newly emerged pioneer and fibrous roots to respond differently to restrictions in soil moisture. We hypothesized that fibrous roots would exhibit greater growth plasticity and greater physiological impairment from soil moisture deficits, especially under heterogeneous conditions. We compared the responses of fibrous and pioneer roots of olive seedlings (Olea europaea) to localized and uniform soil moisture deficits in transparent containers in the greenhouse. In comparison with uniformly wet conditions, uniformly dry conditions caused reduced shoot photosynthesis and reduced shoot growth, but no significant effect on root morphology, root respiration (measured in aerated buffer solution using excised roots) or electrolyte leakage as a function of root age. Under heterogeneous soil moisture conditions, root growth tended to preferentially occur in the moist sector, especially in the pioneer roots. In comparison with pioneer roots in the moist sector, pioneer roots in the dry sector had higher tissue density and higher suberin content, but no shift in root respiration, non-structural carbohydrates or electrolyte leakage. In contrast, fibrous roots in the dry sector exhibited evidence of impaired physiology in older (>38 days) roots compared with similar age fibrous roots in the moist sector. While we anticipated that, compared with pioneer roots, fibrous roots would be more sensitive to soil moisture deficits as expressed by higher electrolyte leakage, we did not expect the strong growth plasticity of pioneer roots under heterogeneous soil moisture conditions. Differentiating the responses of these two very different root types can improve our understanding of how different portions of the root system of woody plants cope with soil moisture deficits. [ABSTRACT FROM AUTHOR]

Sucrose (Suc) synthase (Sus) is the major enzyme of Suc breakdown for cellulose biosynthesis in cotton (Gossypium hirsutum) fiber, an important source of fiber for the textile industry. This study examines the tissue-specific expression, relative abundance, and temporal expression of various Sus transcripts and proteins present in cotton. A novel isoform of Sus (SusC) is identified that is expressed at high levels during secondary cell wall synthesis in fiber and is present in the cell wall fraction. The phylogenetic relationships of the deduced amino acid sequences indicate two ancestral groups of Sus proteins predating the divergence of monocots and dicots and that SusC sequences form a distinct branch in the phylogeny within the dicot-specific clade. The subcellular location of the Sus isoforms is determined, and it is proposed that cell wall-localized SusC may provide UDP-glucose for cellulose and callose synthesis from extracellular sugars. [ABSTRACT FROM AUTHOR]

Bast (phloem) fibers, tension wood fibers, and other cells with gelatinous-type secondary walls are rich in crystalline cellulose. In developing bast fibers of flax (Linum usitatissimum), a galactan-enriched matrix (Gn-layer) is gradually modified into a mature cellulosic gelatinous-layer (G-layer), which ultimately comprises most of the secondary cell wall. Previous studies have correlated this maturation process with expression of a putative Β-galactosidase. Here, we demonstrate that Β-galactosidase activity is in fact necessary for the dynamic remodeling of polysaccharides that occurs during normal secondary wall development in flax fibers. We found that developing stems of transgenic (LuBGAL-RNAi) flax with reduced Β-galactosidase activity had lower concentrations of free Gal and had significant reductions in the thickness of mature cellulosic G-layers compared with controls. Conversely, Gn-layers, labeled intensively by the galactan-specific LM5 antibody, were greatly expanded in LuBGAL-RNAi transgenic plants. Gross morphology and stem anatomy, including the thickness of bast fiber walls, were otherwise unaffected by silencing of Β-galactosidase transcripts. These results demonstrate a specific requirement for Β-galactosidase in hydrolysis of galactans during formation of cellulosic G-layers. Transgenic lines with reduced Β-galactosidase activity also had biochemical and spectroscopic properties consistent with a reduction in cellulose crystallinity. We further demonstrated that the tensile strength of normal flax stems is dependent on Β-galactosidase-mediated development of the phloem fiber G-layer. Thus, the mechanical strength that typifies flax stems is dependent on a thick, cellulosic G-layer, which itself depends on Β-galactosidase activity within the precursor Gn-layer. These observations demonstrate a novel role for matrix polysaccharides in cellulose deposition; the relevance of these observations to the development of cell walls in other species is also discussed. [ABSTRACT FROM AUTHOR]

Paper mulberry (Broussonetia papyrifera L. Vent) is well known for its bark fibers, which are used for making paper, cloth, rope, etc. It was found that, in addition to its well-documented role in the enhancement of plant salt tolerance, overexpression of the Na+/H+ antiporter (AtNHX5) gene in paper mulberry plants showed high drought tolerance. After exposure to water deficiency and salt stress, the wild-type (WT) plants all died, while the AtNHX5-overexpressing plants remained alive under high salt stress, and had a higher survival rate (>66%) under drought stress. Measurements of ion levels indicated that Na+ and K+ contents were all higher in AtNHX5-overexpressing leaves than in WT leaves in high saline conditions. The AtNHX5 plants had higher leaf water content and leaf chlorophyll contents, accumulated more proline and soluble sugars, and had less membrane damage than the WT plants under water deficiency and high saline conditions. Taken together, the results indicate that the AtNHX5 gene could enhance the tolerance of paper mulberry plants to multiple environmental stresses by promoting the accumulation of more effective osmolytes (ions, soluble sugars, proline) to counter the osmotic stress caused by abiotic factors. [ABSTRACT FROM AUTHOR]

Members of glycosyltransferase protein families GT8, GT43 and GT47 are implicated in the biosynthesis of xylan in the secondary cell walls of Arabidopsis. The Arabidopsis mutant irx8 has a 60% reduction in xylan. However, over-expression of an ortholog of Arabidopsis IRX8, poplar PoGT8D, in Arabidopsis irx8 mutant could not restore xylan synthesis. The functions of tree GT8D genes remain unclear. We identified two GT8 gene homologs, PtrGT8D1 and PtrGT8D2, in Populus trichocarpa. They are the only two GT8D members and are abundantly and specifically expressed in the differentiating xylem of P. trichocarpa. PtrGT8D1 transcript abundance was >7 times that of PtrGT8D2. To elucidate the genetic function of GT8D in P. trichocarpa, the expression of PtrGT8D1 and PtrGT8D2 was simultaneously knocked down through RNAi. Four transgenic lines had 85–94% reduction in transcripts of PtrGT8D1 and PtrGT8D2, resulting in 29–36% reduction in stem wood xylan content. Xylan reduction had essentially no effect on cellulose quantity but caused an 11–25% increase in lignin. These transgenics exhibit a brittle wood phenotype, accompanied by increased vessel diameter and thinner fiber cell walls in stem xylem. Stem modulus of elasticity and modulus of rupture were reduced by 17–29% and 16–23%, respectively, and were positively correlated with xylan content but negatively correlated with lignin quantity. These results suggest that PtrGT8Ds play key roles in xylan biosynthesis in wood. Xylan may be a more important factor than lignin affecting the stiffness and fracture strength of wood. [ABSTRACT FROM AUTHOR]

Transcription factors play key roles in plant development through their interaction with cis-elements and/or other transcription factors. A HD-Zip IV family transcription factor, G̲ossypium ḇarbadense M̲eristem Ḻayer 1 (GbML1) has been identified and characterized here. GbML1 specifically bound to the L1 box and the promoters of GbML1 and GbRDL1. GbML1 physically interacted with a key regulator of cotton fibre development, GbMYB25. Truncated and point mutation assays indicated the START-SAD domain was required for the binding to the C terminal domain (CTD) of GbMYB25. GbML1 overexpression in Arabidopsis increased the number of trichomes on stems and leaves and increased the accumulation of anthocyanin in leaves. Taken together, the L1 box binding protein, GbML1 was identified as the first partner for GbMYB25 and the role of START domain was discovered to be a protein binding domain in plants. Our findings will help the improvement of cotton fibre production and the understanding of the key role of HD-Zip family and MYB family in plants. [ABSTRACT FROM AUTHOR]

The recombinant Saccharomyces cerevisiae strain C468/pGAC9 has an unstable hybrid plasmid pGAC9, which directs production of glucoamylase. A fibrous cotton material with a good adsorption capability for recombinant S. cerevisiae cells was used as the immobilization matrix in an internal loop airlift-driven fibrous bed bioreactor (ILALFBB) system. With batch cultures in the ILALFBB, the fraction of plasmid-carrying cells was 72% after more than 2 days cultivation, which was two times higher than that in the conventional free-cell culture. Correspondingly, a high activity of glucoamylase (GA; 113 U/l) was achieved with a high productivity of 43 U/l/h. The ILALFBB system also maintained a high fraction of viable plasmid-carrying of 74% for glucoamylase production during repeated-batch cultures, achieving a high glucoamylase activity of 140 U/l with a productivity of 19–130 U/l/h in all 14 batches studied during 19.8 days. The stable and long-term glucoamylase production from the ILALFBB was attributed to the effect of cell immobilization on plasmid stability. Plasmid-carrying cells were preferentially retained in the fibrous matrix because of their ability to adhere to the fiber surface and to form cell aggregates higher than those of plasmid-free cells. The repeated batch using immobilized cell of recombinant S. cerevisiae in the ALALFBB system thus provides a feasible method for stable, long-term and high-level production of glucoamylase. [ABSTRACT FROM AUTHOR]

Throughout the Southern Great Plains, wheat is managed frequently as a dual-purpose crop, but this production paradigm is not necessarily applicable throughout other regions of the United States, and a wider array of management options can be considered for forage-only uses of cereal grains. Our objectives were to assess the fall-growth potential of wheat (Triticum aestivum L.), triticale (X Triticosecale Wittmack), and oat (Avena sativa L.) cultivars in Wisconsin, and then to further evaluate and compare the fiber composition and TDN of these fall-grown forages. For 2006, yields of DM for all cultivars increased quadratically (P ⩽ 0.048) over fall harvest dates, reaching a maximum of 3,967 kg/ha for Ogle oat. All oat cultivars exhibited stem elongation and also displayed a collective 2 to 1 yield advantage over vegetative wheat cultivars on the final (October 30) harvest date. Growing conditions were more favorable during 2007, and yields were improved for all cultivars. Yields of DM for all cultivars increased quadratically (P ⩽ 0.021) across harvest dates, and oat cultivars maintained the identical 2 to 1 yield advantage over wheat cultivars (6,275 vs. 3,203 kg/ha) that was observed for 2006. Triticale exhibited yields intermediate between oat and wheat during both years. Concentrations of NDF increased quadratically (P ⩽ 0.012) across harvest dates for all cultivars during both years of the experiment; however, these increases occurred primarily between mid September and early October with limited responses thereafter. Oat and triticale cultivars had greater (P < 0.001) concentrations of NDF than wheat cultivars on 5 of 6 harvest dates throughout the experiment. Estimates of TDN exhibited various polynomial responses to harvest date during 2006, but the magnitude of these changes was relatively small. During 2007, TDN declined linearly (P ⩽ 0.038) for grain-type oat, but no relationship with harvest date was observed for other cultivars (P > 0.072), including forage-type oat. Although TDN estimates generally were relatively static across harvest dates, the concentrations of truly digestible components constituting the total TDN pool were quite fluid. Generally, reductions of truly digestible CP were offset by increases in truly digestible nonfiber carbohydrate, truly digestible fiber, or both. The relatively stable energy densities for cereal-grain cultivars observed across harvest dates suggest that a broad window of opportunity exists for usage, including a single harvest as silage. [ABSTRACT FROM AUTHOR]

Cotton fibres are hair-like single-cells that elongate to several centimetres long after their initiation from the ovule epidermis at anthesis. The accumulation of malate, along with K+ and sugars, is thought to play an important role in fibre elongation through osmotic regulation and charge balance. However, there is a lack of evidence for or against such an hypothesis. Phosphoenolpyruvate carboxylase (PEPC) is a key enzyme responsible for the synthesis of malate. The potential role of PEPC in cotton fibre elongation is examined here. Developmentally, PEPC activity was higher at the rapid elongation phase than that at the slow elongation stage. Genotypically, PEPC activity correlated positively with the rate of fibre elongation and the final fibre length attained. Importantly, suppression of PEPC activity by LiCl that reduces its phosphorylation status decreased fibre length. To examine the molecular basis underlying PEPC activity, two cDNAs encoding PEPC, GhPEPC1 and 2, were cloned, which represents the major PEPC genes expressed in cotton fibre. RT-PCR analyses revealed that GhPEPC1 and 2 were highly expressed at the rapid elongation phase but weakly at the slow-to-terminal elongation period. In situ hybridization detected mRNA of GhPEPC1 and 2 in 1 d young fibres but not in the ovule epidermis prior to fibre initiation. Collectively, the data indicate that cotton fibre elongation requires high activity of PEPC, probably through the expression of the GhPEPC1 and 2 genes. [ABSTRACT FROM PUBLISHER]

Aims: To study the effect of selected bacterial strains on hemp water-retting and properties of retted fibre. Methods and Results: The trials were performed in laboratory tanks. The traditional water-retting process, without inoculum addition, was compared to a process modified by inoculating water tanks with two selected pectinolytic bacteria: the anaerobic strain Clostridium sp. L1/6 and the aerobic strain Bacillus sp. ROO40B. Six different incubation times were compared. Half the fibre obtained from each tank was combed. Micromorphological analyses were performed by scanning electron microscopy on uncombed and combed fibres. Moreover, organoleptic and chemical analyses of uncombed fibres were performed. Conclusions: The inoculum, besides speeding up the process, significantly improved the fibre quality. The fibre was not damaged by mechanical hackling, thanks to the good retting level obtained by the addition of selected strains, differently to what happened with the traditionally retted fibre. The best fibre quality was obtained after 3–4 days of retting with the addition of the bacterial inoculum. Significance and Impact of the Study: Retting is the major limitation to an efficient production of high-quality hemp fibres. The water-retting process and fibre quality were substantially improved by simultaneously inoculating water tanks with two selected pectinolytic strains. [ABSTRACT FROM AUTHOR]

Aims: To determine the effect of carbon sources on cellulose produced by Gluconacetobacter xylinus strain ATCC 53524, and to characterize the purity and structural features of the cellulose produced. Methods and Results: Modified Hestrin Schramm medium containing the carbon sources mannitol, glucose, glycerol, fructose, sucrose or galactose were inoculated with Ga. xylinus strain ATCC 53524. Plate counts indicated that all carbon sources supported growth of the strain. Sucrose and glycerol gave the highest cellulose yields of 3·83 and 3·75 g l−1 respectively after 96 h fermentation, primarily due to a surge in cellulose production in the last 12 h. Mannitol, fructose or glucose resulted in consistent rates of cellulose production and yields of >2·5 g l−1. Solid state 13C CP/MAS NMR revealed that irrespective of the carbon source, the cellulose produced by ATCC 53524 was pure and highly crystalline. Scanning electron micrographs illustrated the densely packed network of cellulose fibres within the pellicles and that the different carbon sources did not markedly alter the micro-architecture of the resulting cellulose pellicles. Conclusions: The production rate of bacterial cellulose by Ga. xylinus (ATCC 53524) was influenced by different carbon sources, but the product formed was indistinguishable in molecular and microscopic features. Significance and Impact of the Study: Our studies for the first time examined the influence of different carbon sources on the rate of cellulose production by Ga. xylinus ATCC 53524, and the molecular and microscopic features of the cellulose produced. [ABSTRACT FROM AUTHOR]

A silencing vector for cotton (Gossypiurn hirsutum) was developed from the geminivirus Cotton leaf crumple virus (CLCrV). The CLCrV coat protein gene was replaced by up to 500 bp of DNA homologous to one of two endogenous genes, the magnesium chelatase subunit I gene (ChlI) or the phytoene desaturase gene (PDS). Cotyledons of cotton cultivar 'Deltapine 5415' bombarded with the modified viral vectors manifested chlorosis due to silencing of either Chil or PDS in approximately 70% of inoculated plants after 2 to 3 weeks. Use of the green fluorescence protein gene showed that replication of viral DNA was restricted to vascular tissue and that the viral vector could transmit to leaves, roots, and the ovule integument from which fibers originate. Temperature had profound effects on vector DNA accumulation and the spread of endogenous gene silencing. Consistent with reports that silencing against viruses increases at higher temperatures, plants grown at a 30°C/26°C day/night cycle had a greater than 10-fold reduction in viral DNA accumulation compared to plants grown at 22°C/18°C. However, endogenous gene silencing decreased at 30°C/26°C. There was an approximately 7 d delay in the onset of gene silencing at 22°C/18°C, but silencing was extensive and persisted throughout the life of the plant. The extent of silencing in new growth could be increased or decreased by changing temperature regimes at various times following the onset of silencing. Our experiments establish the use of the CLCrV silencing vector to study gene function in cotton and show that temperature can have a major impact on the extent of geminivirus-induced gene silencing. [ABSTRACT FROM AUTHOR]

Microtubules are a major structural component of the cytoskeleton and participate in cell division, intracellular transport, and cell morphogenesis. In the present study, 795 cotton tubulin expressed sequence tags were analysed and 19 β-tubulin genes (TUB) cloned from a cotton cDNA library. Among the group, 12 cotton TUBs (GhTUBs) are reported for the first time here. Transcription profiling revealed that nine GhTUBs were highly expressed in elongating fibre cells as compared with fuzzless-lintless mutant ovules. Treating cultured wild-type cotton ovules with exogenous phytohormones showed that individual genes can be induced by different agents. Gibberellin induced expression of GhTUB1 and GhTUB3, ethylene induced expression of GhTUB5, GhTUB9, and GhTUB12, brassinosteroids induced expression of GhTUB1, GhTUB3, GhTUB9, and GhTUB12, and lignoceric acid induced expression of GhTUB1, GhTUB3, and GhTUB12. When GhTUBs were transformed into the Saccharomyces cerevisiae inviable mutant, tub2, which is deficient in β-tubulin, one ovule-specific and eight of nine fibre-preferential GhTUBs rescued this lethality. This study suggests that the proteins encoded by cotton GhTUBs are involved during cotton fibre development. [ABSTRACT FROM PUBLISHER]

The article provides an overview of the plant fibers that have been visualized and that are part of the complex networks that include the reactive oxygen species (ROS) and ROS signaling in plant cells. Focus is made on the improvements on ROS imaging, findings regarding additional sources of ROS, and ROS signal recognition and transduction.

The occurrence and distribution of (1,4)-β-galactan in wood cells of poplar (Populus trichocarpa Torr. & A. Gray × P. koreana Rehder) were studied by immunolabeling with a monoclonal antibody (LM5) specific to this carbohydrate epitope. Immunofluorescence microscopy revealed exclusive binding of the LM5 antibody to tension wood fibers, indicating the specific presence of (1,4)-β-galactan in cell walls of this wood cell type. Higher magnifications achieved with the fluorescence microscope and additional immunogold electron microscopy showed that the binding of the LM5 antibody was mainly restricted to a narrow cell wall area between the gelatinous G-layer and the secondary cell wall. This labeling pattern strongly suggests a role of (1,4)-β-galactan in cross-linking the G-layer and secondary cell wall. Furthermore, the exclusive localization of (1,4)-β-galactan in tension wood strengthens the view that this carbohydrate epitope can be considered a highly specific marker of reaction wood formation in mechanically stressed trees. [ABSTRACT FROM AUTHOR]

One hundred and twenty-eight Bacillus thuringiensis isolates from fields of different ecological regions of Iran were collected to study the distribution and diversity of Dipteran-specific cry and cyt genes. The percentage of samples with Bt showed significant differences between different regions and also between different fields. The most Bt frequency was observed in the soil samples collected from Caspianic zone (7%) and soils of cotton (17%). Characterization of isolates was based on morphological characteristics of crystals, plasmid profiles and protein band patterns as well as PCR analysis using general and specific primers for 22 different cry and cyt genes encoding proteins active against mosquitoes. Thirty-eight different cry gene profiles were detected in this collection. Several of them were found to be different from all previously published profiles and none of the previous researches reported these numbers of profiles. Strains containing cry2-type genes were the most abundant and represent 57.1% of the isolates. Strains harboring cry24 and cry10 genes were also highly abundant (38.7 and 32.8%, respectively). cry11, cry4, cry17, cry19, cry21, cry29, cyt1, and cry9 genes were less abundant, found in 25.7, 14.3, 11.4, 1.4, 4.3, 1.4, and 10% of the strains, respectively. Among the cry2 gene containing isolates, 37.5% strains harbored cry2Aa, 55% cry2Ab, 2.5% cry2Ac, and 5% other or novel cry2-type genes . Among the cry4 gene containing isolates, 0% strains harbored cry4A, 60% cry4B, and 40% cry4C, cry4D or novel cry4 type genes. Finally, based on crystal morphology, protein patterns and PCR, 21 strains were selected as potentially high Dipteran-active for bioassays. Also our results showed that some of the isolates may harbor minimum a putative novel cry gene. [ABSTRACT FROM AUTHOR]

A complex of hemipterans, especially the tarnished plant bug, Lygus lineolarzs (Palisot de Beauvois) (Hemiptera: Miridae), has become a major target of insecticides in flowering cotton, Gossypium hirsutum L., in the mid-southern United States. Sampling protocols for this complex during this period of cotton development are poorly established, resulting in uncertainty about when infestations warrant treatment. Nine direct and indirect sampling methods were evaluated for bias, precision, and efficiency in cotton throughout the Mid-South during 2005 and 2006. The tarnished plant bug represented 94% of the bug complex in both years. Sweep-net and black drop-cloth methods were more efficient than other direct sampling methods, but they were biased toward adults and nymphs, respectively. Sampling dirty blooms was the most efficient indirect sampling method. The sweep-net, whole-plant, and dirty-bloom methods were more accurate than the other sampling methods evaluated based on correlations with other sampling methods. Variability attributed to the person collecting the sample was significant for all sampling methods, but least significant for the dirty-square method. Further research is needed to establish thresholds based on sweep-net, drop- cloth, dirty-square, and dirty-bloom sampling methods as these methods provide the best combinations of accuracy and efficiency for sampling tarnished plant bugs in cotton. [ABSTRACT FROM AUTHOR]

Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is an important lepidopteran pest of cotton (Gossypium spp.) in Australia and the Old World. From 2002, F2 screens were used to examine the frequency of resistance alleles in Australian populations of H. armigera to Bacillus thuringiensis (Bt) CrylAc and Cry2Ab, the two insecticidal proteins present in the transgenic cotton Bollgard II. At that time, Ingard (expressing CrylAc) cotton had been grown in Australia for seven seasons, and Boilgard H was about to be commercially released. The principal objective of our study was to determine whether sustained exposure caused an elevated frequency of alleles conferring resistance to CrylAc in a species with a track record of evolving resistance to conventional insecticides. No major alleles conferring resistance to CrylAc were found. The frequency of resistance alleles for CrylAc was <0.0003, with a 95% credibility interval between 0 and 0.0009. In contrast, alleles conferring resistance to Cry2Ab were found at a frequency of 0.0033 (0.0017,0.0055). The first isolation of this allele was found before the widespread deployment of Bollgard H. For both toxins the experiment-wise detection probability was 94.4%. Our results suggest that alleles conferring resistance to CrylAc are rare and that a relatively high baseline frequency of alleles conferring resistance to Cry2Ab existed before the introduction of Bt cotton containing this toxin. [ABSTRACT FROM AUTHOR]

Aims: To optimize the solid-state cultivation conditions for xylanase production using agriresidues and testing the biobleaching efficiency of xylanase on nonwoody plant fibre materials. Methods and Results: An extracellular cellulase free xylanase was produced from Bacillus subtilis C 01 using various inexpensive substrates under solid-state cultivation. High level of xylanase production (135 IU gds−1) was observed when grown on wheat bran followed by maize powder (50 IU gds−1). The maximum xylanase (136 IU gds−1) production was occurred in wheat bran-to-moisture ratio of 1 : 1 at 72 h. The xylanase pretreated pulp samples of banana, silk cotton and cotton showed an increased brightness of 19·6, 11·6 and 7·9%, respectively. Conclusions: The enzyme-aided biobleaching results indicate that the xylanase has potential application in enhancing the brightness of nonwoody plant fibre pulp. Significance and Impact of the Study: This is the first report on biobleaching of banana fibres, silk cotton and cotton pulps using xylanase. The biobleaching results of secondary fibres are promising and can be transferred to paper mills, which utilize nonwoody plant fibres as a raw material for paper production. [ABSTRACT FROM AUTHOR]

The influence of southern green stink bug, Nezara viridula (L.), adults (males and females) and fourth to fifth instars on cotton, Gossypium hirsutum L., boll abscission, seedcotton yield, fiber quality, and seed viability was evaluated in field studies conducted during 2004 and 2005. Cotton boils representing several age classes ranging from 0–600 heat units were individually infested with a specific gender or life stage of southern green stink bug. Adults and nymphs induced abscission of bolls that accumulated 0–280 heat units after anthesis. Seedcotton yield was significantly lower in boils infested with adults (males and females) and late instars through ≈500 heat units after anthesis. Southern green stink bug feeding on boils significantly affected the physical fiber properties of micronaire (measure of fiber fineness or maturity), strength, uniformity, and fiber length. Discolored cotton lint in the stink bug-infested boils was more common than in noninfested bolls. Seed germination and development of normal seedlings for seed harvested from stink bug-infested boils that accumulated ≤500 heat units beyond anthesis were significantly lower compared with noninfested bolls. No significant differences in boll abscission, yield, fiber quality, and seed germination were detected between southern green stink bug males and females or between adults and fourth to fifth instars. [ABSTRACT FROM AUTHOR]

The article presents abstracts on protein and fiber digestion topics which include "Protein requirements of Nellore bulls, steers and heifers in Brazil," "Digestibility of cottonseed with Tifton 85 hay fed free-choice to beef steers" and "Performance of beef heifers and digestibility of steers fed whole cotton seed, corn gluten feed and pigeon peas."