Helianthus
Sea Anemones
Cnidarian Venoms
Hybridization, Genetic
Trans-Cinnamate 4-Monooxygenase
Orobanche
Plant Leaves
Asteraceae
Datura
Peronospora
Plant Transpiration
Performance of beef cows receiving cull beans, sunflower meal, and canola meal as protein supplements while grazing native winter range in Eastern Colorado. (1/400)
A 2-yr grazing performance study was conducted in Eastern Colorado to evaluate the effects of feeding raw cull beans (Phaseolus vulgaris) or canola meal, compared to sunflower meal, to beef cows grazing dormant, native winter range on body weight and body condition score (BCS) change, reproductive performance, and calf performance. Ninety-five pregnant, spring-calving crossbred cows (541 +/- 51 kg) in 1995 to 1996 and 65 cows (602 +/- 60 kg) in 1996 to 1997 were randomly assigned to one of five treatments (19 and 13 cows per treatment in 1995 to 1996 and 1996 to 1997, respectively): 1) unprocessed Great Northern beans to supply 182 g/d of CP (GNB); 2) canola meal to supply 182 g/d of CP (CM); 3) a mixture of Great Northern beans and sunflower meal, each to supply 91 g/d of CP, for a total of 182 g/d of CP (MIX); 4) sunflower meal to supply 182 g/d of CP (SFM+); and 5) sunflower meal to supply 91 g/d of CP (SFM-). Cow weight and body condition performance were broken into a gestation and a lactation phase in 1995 to 1996; calves were weighed at birth, at the end of the lactation phase in April, and at weaning the following September. Only gestation performance was monitored in 1996 to 1997, and subsequent calf birth and weaning weight were recorded. The SFM- group lost more weight during the gestation phase than other treatments (P < .05), yet no differences were detected for gestation phase daily BCS change, calf birth weight, lactation phase daily weight change, lactation phase daily BCS change, first-service conception rate to AI, or overall pregnancy rate. Off-test calf weight was higher in April for calves from dams of the SFM+ and CM treatments than for calves from dams on the GNB or SFM- treatments (P < .05), and calves from cows on the CM treatment were heavier in April than calves from cows on the MIX treatment (P < .05). No differences in calf weight were present at weaning. Consumption of beans by cows on the GNB treatment was low because of palatability problems. Mixing the beans with sunflower meal in the MIX treatment eliminated this problem. Canola meal, Great Northern beans, or a combination of sunflower meal and Great Northern beans were comparable to sunflower meal as protein supplements for beef cows grazing native winter range, despite obvious palatability problems with the beans. (+info)Effect of fiber source on cell wall digestibility and rate of passage in rabbits. (2/400)
The influence of fiber source on fiber digestion and mean retention time was investigated. Six fibrous feedstuffs with wide differences in chemical composition and particle size were selected: paprika meal, olive leaves, alfalfa hay, soybean hulls, sodium hydroxide-treated barley straw, and sunflower hulls. Six diets were formulated to contain one of these ingredients as the sole source of fiber. To avoid nutrient imbalances, fiber sources were supplemented with different proportions of a concentrate free of fiber based on soy protein isolate, wheat flour, lard, and a vitamin and mineral mix to obtain diets containing at least 18.5% CP and 5% starch. Fecal apparent digestibility of nonstarch polysaccharides (NSPd) and its monomers, NDF, NDF-ADL, and ADF-ADL, were determined using four New Zealand White x California growing rabbits per diet. Total, ileorectal, and cecal mean retention times (tMRT, i-rMRT, and cMRT, respectively) were determined for diets based on paprika meal, olive leaves, soybean hulls, and sunflower hulls in 16 does (four per diet) fitted with T-cannulas at the terminal ileum. In both trials, DMI was negatively correlated with the proportion of fine particles (FP: < .315 mm) and positively correlated with the proportion of large particles (LP: > 1.25 mm) (P < .01). Stepwise regression analysis showed that FP was the dietary characteristic best related to digestibilities of NSP, uronic acids, glucose and NDF, tMRT, and cMRT (P < .001), showing a positive correlation with these variables. In all these cases, this procedure selected the proportion of large particles as a second variable in the model. Degree of lignification of NDF, considering lignin as the difference between ADL and acid detergent cutin, was only included as the third variable for the model of NDF digestibility. Digestibility of NSP was positively correlated with those of NDF, NDF-ADL, and ADF-ADL (r = .82, .87 and .85, respectively, P < .001); the latter was also highly correlated with the digestibility of the glucose included in the NSP fraction (r = .86; P < .001). Cecal mean retention time accounted for 63% of average tMRT, for most of the variability in tMRT (r = .99; P < .001), and was positively related to NSPd (r = .89; P < .001). From these results, we conclude that particle size is a major factor affecting fiber digestion efficiency, rate of passage, and feed intake in rabbits. (+info)Hybrid zones and the genetic architecture of a barrier to gene flow between two sunflower species. (3/400)
Genetic analyses of reproductive barriers represent one of the few methods by which theories of speciation can be tested. However, genetic study is often restricted to model organisms that have short generation times and are easily propagated in the laboratory. Replicate hybrid zones with a diversity of recombinant genotypes of varying age offer increased resolution for genetic mapping experiments and expand the pool of organisms amenable to genetic study. Using 88 markers distributed across 17 chromosomes, we analyze the introgression of chromosomal segments of Helianthus petiolaris into H. annuus in three natural hybrid zones. Introgression was significantly reduced relative to neutral expectations for 26 chromosomal segments, suggesting that each segment contains one or more factors that contribute to isolation. Pollen sterility is significantly associated with 16 of these 26 segments, providing a straightforward explanation of why this subset of blocks is disadvantageous in hybrids. In addition, comparison of rates of introgression across colinear vs. rearranged chromosomes indicates that close to 50% of the barrier to introgression is due to chromosomal rearrangements. These results demonstrate the utility of hybrid zones for identifying factors contributing to isolation and verify the prediction of increased resolution relative to controlled crosses. (+info)A monomer-dimer equilibrium modulates the interaction of the sunflower homeodomain leucine-zipper protein Hahb-4 with DNA. (4/400)
We have analysed the interaction of the sunflower homeodomain leucine-zipper (Hd-Zip) protein Hahb-4 with DNA. The complete Hd-Zip domain from Hahb-4 was able to select specific sequences from a random oligonucleotide mixture that contained a 9-bp core with four fixed and five degenerate positions. Analysis of the binding of some of the selected sequences suggests that Hahb-4 preferentially binds the dyad-symmetrical sequence CAAT(A/T)ATTG. Single-nucleotide replacements at positions 1, 5 or 9 of this sequence produced a decrease in binding of 2-4-fold. DNA binding as a function of protein concentration was non-hyperbolic. This behaviour could be explained by an equation in which dimer formation is a pre-requisite for DNA binding. A global dissociation constant (Kd) of 1.31x10(-14) M2 could be calculated. The removal of the leucine zipper promoted a change in specificity and a decrease in binding affinity (Kd=5. 03x10(-5) M). Mutation of Phe-20 of the homeodomain into Leu completely abolished DNA binding. The mutant protein, however, was able to inhibit DNA binding by the non-mutant form, presumably through the formation of heterodimers. The analysis of this inhibitory effect at different mutant concentrations allowed the estimation of the Kd for the dimer-monomer equilibrium [about (2-4)x10(-6) M]; from this, a Kd of 3-6x10(-9) M for the dimer-DNA complex could be estimated. The results obtained indicate that the formation of dimers is the main factor influencing the interaction of Hahb-4 with DNA. It is proposed that shifts in a dimer-monomer equilibrium could be used within the cell to modulate the interaction of this protein with target genes. (+info)Polyadenylation accelerates the degradation of the mitochondrial mRNA associated with cytoplasmic male sterility in sunflower. (5/400)
In sunflower, PET1-cytoplasmic male sterility is correlated with the presence of a novel mitochondrial gene (orf522) located 3' to the atpA gene. The dicistronic atpA-orf522 transcripts are preferentially destabilized in male florets of 'restored to fertility' plants as compared with sterile plants. In this report, we show that atpA-orf522 transcripts may be polyadenylated in vivo at their 3' termini and that a tissue-specific increase in the level of polyadenylated atpA-orf522 transcripts correlates with the tissue-specific instability of atpA-orf522 mRNAs in male florets of the restored hybrid plants. In addition, we have identified two distinct ribonuclease activities in sunflower mitochondria, one of which preferentially degrades polyadenylated as compared with non-polyadenylated RNA substrates corresponding to the 3' UTR of atpA-orf522 transcripts. These in vivo and in vitro results show that polyadenylation is involved in the degradation pathway of the mitochondrial atpA-orf522 transcripts and that polyadenylation can be developmentally regulated by a nuclear gene(s) upon restoration of fertility. (+info)Milk cytokines and subclinical breast inflammation in Tanzanian women: effects of dietary red palm oil or sunflower oil supplementation. (6/400)
Previously, we have found that subclinical breast inflammation, as indicated by raised breastmilk concentrations of sodium and the inflammatory cytokine, interleukin-8 (IL-8), was highly prevalent in Bangladesh and associated with poor infant growth. In order to investigate further the prevalence of subclinical breast inflammation and to assess the impact of dietary intervention, we studied rural Tanzanian women taking part in a study of dietary sunflower or red palm oil supplementation during late pregnancy and lactation. We measured breastmilk concentrations of IL-8, the anti-inflammatory cytokine, transforming growth factor-beta2 (TGF-beta) and the ratio of sodium to potassium. We also estimated systemic inflammation by plasma concentrations of the acute phase proteins, alpha1-acid glycoprotein and C-reactive protein. There were highly significant intercorrelations among milk Na/K ratio and concentrations of IL-8 and TGF-beta, the last only after treatment with bile salts which also improved TGF-beta recovery in the enzyme-linked immunosorbent assay (ELISA). Plasma acute phase protein concentrations tended to correlate with milk Na/K ratio and IL-8, suggesting that subclinical breast inflammation was related to systemic inflammation. Dietary supplementation with vitamin E-rich sunflower oil but not provitamin A-containing red palm oil decreased milk Na/K, IL-8 and TGF-beta at 3 months postpartum; however, the effect was significant only for Na/K ratio. The results suggest that milk Na/K ratio, IL-8, and TGF-beta all measure the same phenomenon of subclinical breast inflammation but that Na/K ratio, having the lowest assay variability, is the most useful. Subclinical breast inflammation may result in part from systemic inflammation and may be improved by increased dietary intake of vitamin E-rich sunflower oil. (+info)Direct kinetic evidence for folding via a highly compact, misfolded state. (7/400)
The 2 S seed storage protein, sunflower albumin 8 (SFA-8), contains an unusually high proportion of hydrophobic residues including 16 methionines (some of which may form a surface hydrophobic patch) in a disulfide cross-linked, alpha-helical structure. Circular dichroism and fluorescence spectroscopy show that SFA-8 is highly stable to denaturation by heating or chaotropic agents, the latter resulting in a reversible two-state unfolding transition. The small m(U) (-4.7 M(-1) at 10 degrees C) and DeltaC(p) (-0.95 kcal mol(-1) K(-1)) values indicate that relatively little nonpolar surface of the protein is exposed during unfolding. Commensurate with the unusual distribution of hydrophobic residues, stopped-flow fluorescence data show that the folding pathway of SFA-8 is highly atypical, in that the initial product of the rapid collapse phase of folding is a compact nonnative state (or collection of nonnative states) that must unfold before acquiring the native conformation. The inhibited folding reaction of SFA-8, in which the misfolded state (m(M) = -0.95 M(-1) at 10 degrees C) is more compact than the transition state for folding (m(T) = -2.5 M(-1) at 10 degrees C), provides direct kinetic evidence for the transient misfolding of a protein. (+info)Genetic architecture of species differences in annual sunflowers: implications for adaptive trait introgression. (8/400)
Genetic architecture may profoundly influence the ability of adaptive traits to spread between species via introgressive hybridization. Here, we examine the genomic location of quantitative trait loci (QTL) associated with pollen sterility and morphological traits distinguishing two annual sunflowers, Helianthus annuus and H. debilis ssp. cucumerifolius. These species are of particular interest since they hybridize naturally, and the form of H. annuus in Texas (called ssp. texanus) is thought to have arisen through introgression. Analysis of 226 BC(1) progeny from a cross between H. annuus and H. debilis revealed 56 QTL for 15 morphological traits and 2 QTL for pollen sterility. Four morphological QTL are tightly linked (<10 cM) to one or more sterility factors and 7 are closely allied with underrepresented and presumably negatively selected chromosomal blocks. Although these 11 QTL seem unlikely to move between the species, no barrier to introgression was detected for the remaining 45 morphological QTL. In fact, due to widespread pleiotropy (or tight linkage), the introgression of just three small chromosomal blocks appears sufficient to largely recover the phenotype of ssp. texanus. Subsequent work will test for the occurrence and fitness consequences of the identified QTL in natural populations of ssp. texanus. (+info)I'm sorry for any confusion, but "Helianthus" is not a medical term. It is the genus name for sunflowers in the family Asteraceae. Sunflowers are native to North America and are known for their large, daisy-like flowers and tall stems. They have various uses, including ornamental purposes, food (seeds and oil), and medicinal applications in some traditional systems of medicine. However, there isn't a widely accepted medical definition associated with the term "Helianthus."
Sea Anemones are not considered a medical term, but they are rather marine biology organisms. They are a group of predatory sea animals belonging to the phylum Cnidaria, which also includes corals, jellyfish, and hydras. Sea anemones typically have a cylindrical or bell-shaped body crowned with tentacles that bear stinging cells used for capturing prey.
However, in a medical context, the term "anemone" is sometimes used to describe a type of skin lesion characterized by its resemblance to the sea anemone's shape and appearance. An anemone lesion is a rare cutaneous condition that presents as a solitary, red, or purple papule with multiple radiating fronds, often occurring on the face or neck. The lesions may be tender or pruritic (itchy) and can persist for several weeks to months.
It's important to note that sea anemones themselves do not have a direct medical relevance, but they can serve as a source of inspiration for medical terminology due to their unique morphological features.
Cnidarian venoms are toxic substances produced by members of the phylum Cnidaria, which includes jellyfish, sea anemones, corals, and hydroids. These venoms are primarily contained in specialized cells called cnidocytes or nematocysts, which are found in the tentacles of these animals. When a cnidarian comes into contact with prey or a potential threat, the cnidocytes discharge, injecting the venom into the target through a hollow tubule.
Cnidarian venoms are complex mixtures of bioactive molecules, including proteins, peptides, and small organic compounds. The composition of these venoms can vary significantly between different cnidarian species, as well as between different life stages or sexes of the same species. Some cnidarian venoms primarily serve a defensive function, causing pain or other unpleasant symptoms in potential predators, while others have a more offensive role, helping to immobilize prey before consumption.
The effects of cnidarian venoms on humans can range from mild irritation and stinging sensations to severe pain, swelling, and allergic reactions. In some cases, cnidarian envenomations can lead to more serious complications, such as respiratory distress, cardiac arrhythmias, or even death, particularly in individuals with underlying health conditions or allergies to the venom.
Research on cnidarian venoms has led to important insights into the biochemistry and molecular mechanisms of pain, inflammation, and neurotoxicity, as well as the development of new therapeutic strategies for treating various medical conditions. Additionally, understanding the structure and function of cnidarian venom components has inspired the design of novel bioactive molecules with potential applications in drug discovery, pest control, and other areas of biotechnology.
Genetic hybridization is a biological process that involves the crossing of two individuals from different populations or species, which can lead to the creation of offspring with new combinations of genetic material. This occurs when the gametes (sex cells) from each parent combine during fertilization, resulting in a zygote with a unique genetic makeup.
In genetics, hybridization can also refer to the process of introducing new genetic material into an organism through various means, such as genetic engineering or selective breeding. This type of hybridization is often used in agriculture and biotechnology to create crops or animals with desirable traits, such as increased disease resistance or higher yields.
It's important to note that the term "hybrid" can refer to both crosses between different populations within a single species (intraspecific hybrids) and crosses between different species (interspecific hybrids). The latter is often more challenging, as significant genetic differences between the two parental species can lead to various reproductive barriers, making it difficult for the hybrid offspring to produce viable offspring of their own.
Trans-cinnamate 4-monooxygenase is an enzyme that belongs to the class of oxidoreductases. It is specifically categorized as a member of the family of single-donor oxidoreductases, which use NAD or NADP as electron acceptors. This enzyme participates in the phenylpropanoid metabolic pathway and catalyzes the conversion of trans-cinnamic acid to p-coumaric acid using NADPH and oxygen as cofactors. The reaction can be represented as follows:
trans-cinnamic acid + NADPH + H+ + O2 -> p-coumaric acid + NADP+ + H2O
The gene encoding this enzyme is often used as a marker for plant defense responses and stress tolerance.
Orobanche is not a medical term, but a genus of parasitic plants in the family Orobanchaceae. These plants are known as broomrapes and are holoparasites, meaning they rely entirely on other plants for nutrients. They have no chlorophyll and cannot photosynthesize. Instead, they tap into the roots of nearby host plants to extract water and nutrients.
While Orobanche itself is not a medical term, some species of this plant can have negative impacts on human health. For example, if these parasitic plants infect crops, they can reduce yield and quality, leading to economic losses for farmers. In addition, some people may have allergic reactions to the pollen of these plants. However, it's important to note that direct contact with Orobanche plants is unlikely to cause any significant health problems for most people.
I believe there may be a slight misunderstanding in your question. "Plant leaves" are not a medical term, but rather a general biological term referring to a specific organ found in plants.
Leaves are organs that are typically flat and broad, and they are the primary site of photosynthesis in most plants. They are usually green due to the presence of chlorophyll, which is essential for capturing sunlight and converting it into chemical energy through photosynthesis.
While leaves do not have a direct medical definition, understanding their structure and function can be important in various medical fields, such as pharmacognosy (the study of medicinal plants) or environmental health. For example, certain plant leaves may contain bioactive compounds that have therapeutic potential, while others may produce allergens or toxins that can impact human health.
Asteraceae is a family of flowering plants commonly known as the daisy family or sunflower family. It is one of the largest and most diverse families of vascular plants, with over 1,900 genera and 32,000 species. The family includes a wide variety of plants, ranging from annual and perennial herbs to shrubs and trees.
The defining characteristic of Asteraceae is the presence of a unique type of inflorescence called a capitulum, which resembles a single flower but is actually composed of many small flowers (florets) arranged in a dense head. The florets are typically bisexual, with both male and female reproductive structures, and are radially symmetrical.
Asteraceae includes many economically important plants, such as sunflowers, daisies, artichokes, lettuce, chicory, and ragweed. Some species of Asteraceae are also used in traditional medicine and have been found to contain bioactive compounds with potential therapeutic uses.
It's worth noting that the taxonomy of this family has undergone significant revisions in recent years, and some genera and species have been moved to other families or renamed.
'Datura' is a genus of plants that belong to the family Solanaceae, also known as nightshades. These plants are native to North and South America but have been introduced and naturalized in many parts of the world. Some common names for plants in this genus include Jimson weed, thorn apple, and angel's trumpet.
Datura species contain a variety of toxic alkaloids, including scopolamine, atropine, and hyoscyamine, which can have hallucinogenic effects when ingested. However, these plants are also highly poisonous and can cause serious harm or death if consumed. Ingesting even small amounts can result in symptoms such as dilated pupils, dry mouth, rapid heartbeat, confusion, agitation, and delirium.
It is worth noting that Datura is sometimes used in traditional medicine practices, but it should only be administered under the close supervision of a qualified healthcare provider, as improper use can lead to severe adverse effects.
"Peronospora" is a genus of oomycetes, which are organisms that were once classified as fungi but are now known to be more closely related to brown algae and diatoms. These microorganisms are commonly known as downy mildews and can cause significant damage to crops and plants.
Peronospora species are obligate parasites, meaning they require a living host to complete their life cycle. They infect plant tissues through the production of spores that are disseminated by wind or water. Once inside the plant, the spores germinate and produce feeding structures called haustoria that penetrate the plant cells and absorb nutrients.
Peronospora infections can cause a range of symptoms in plants, including leaf spots, stem lesions, and stunted growth. In severe cases, the entire plant may be killed. Some Peronospora species are also known to produce toxins that can further damage the plant.
In medical terms, Peronospora infections are not typically considered a direct threat to human health. However, they can have significant economic impacts on agriculture and food production, which can indirectly affect human health by reducing the availability and increasing the cost of fresh produce. Additionally, some Peronospora species are known to infect medical plants, which could potentially lead to contamination of medical products.
A medical definition for "plant shoots" may not be readily available, as the term is primarily used in botany and horticulture. However, I can provide you with a general definition:
Plant shoots refer to the above-ground portion of a plant, which typically includes structures like stems, leaves, flowers, and buds. Shoots originate from the seed or the growing tip of the plant and are responsible for photosynthesis, nutrient absorption, and reproduction. In some contexts, "plant shoots" might also refer to new growth that emerges from an existing plant, such as when a leaf or stem sprouts a new branch or flower.
Plant transpiration is the process by which water vapor escapes from leaves and other aerial parts of plants to the atmosphere. It is a type of evapotranspiration, which refers to both evaporation from land surfaces and transpiration from plants. Water molecules are absorbed by plant roots from the soil, move up through the xylem tissue to the leaves, and then evaporate from the leaf surface through stomatal pores. This process helps in the transportation of nutrients from the soil to various parts of the plant, regulates the temperature of the plant, and maintains the turgor pressure within the cells. Plant transpiration is influenced by environmental factors such as light intensity, temperature, humidity, and wind speed.