Citrus
Citrus sinensis
Closterovirus
Citrus paradisi
Rhizobiaceae
Citrus aurantiifolia
Limonins
Xanthomonas axonopodis
Cyclohexenes
Oils, Volatile
Xanthomonas
Viroids
Plant Leaves
Hemiptera
Monoterpenes
The haplotype distribution of two genes of citrus tristeza virus is altered after host change or aphid transmission. (1/761)
Genetic variability of citrus tristeza virus (CTV) was studied using the haplotypes detected by single-strand conformation polymorphism (SSCP) analysis of genes p18 and p20 in six virus populations of two origins. The Spanish group included a CTV isolate and subisolates obtained by graft-transmission to different host species. The other included two subisolates aphid-transmitted from a single Japanese isolate. The homozygosity observed for gene p20 was always significantly higher than that expected under neutral evolution, whereas only three populations showed high homozygosity for p18, suggesting stronger host constraints for p20 than for p18. Sequential transmissions of a Spanish isolate to new host species increased the difference between its population and that of the successive subisolates for gene p18, as estimated by the F statistic. Analysis of molecular variance indicated that variation between both groups of populations was not statistically significant, whereas variations between populations of the same group or within populations were significant for both genes studied. Our data indicate that selection affects the haplotype distribution and that adaptation to a new host can be as important or more as the geographical origin. Variation of the CTV populations after host change or aphid transmission may explain in part the wide biological variability observed among CTV isolates. (+info)Nucleotide sequences and taxonomy of satsuma dwarf virus. (2/761)
The nucleotide sequences of genomic RNA1 (6795 nt) and RNA2 (5345 nt) of satsuma dwarf virus (SDV), a tentative member of the genus Nepovirus, were determined. The deduced genome organization of SDV showed similarities to the organization in como-, faba- and nepoviruses. There is extensive amino acid sequence similarity in the N-terminal regions of the proteins encoded by RNA1 and RNA2, as reported previously only for tomato ringspot nepovirus. However, unlike definitive nepoviruses, which have a single coat protein, SDV has two coat proteins. SDV RNA2 does not contain the long (> 1300 nt) 3' non-coding region characteristic of some nepoviruses. Phylogenetic analysis of SDV RNA polymerase placed SDV apart from como-, faba- and nepoviruses. These unique features suggest that SDV is distinct from the Comovirus, Fabavirus and Nepovirus genera, and needs to be separated into a new genus, probably within the family Comoviridae. (+info)The complete genome sequence of the major component of a mild citrus tristeza virus isolate. (3/761)
The genome of the Spanish mild isolate T385 of citrus tristeza virus (CTV) was completely sequenced and compared with the genomes of the severe isolates T36 (Florida), VT (Israel) and SY568 (California). The genome of T385 was 19,259 nt in length, 37 nt shorter than the genome of T36, and 33 and 10 nt longer than those of VT and SY568, respectively, but their organization was identical. T385 had mean nucleotide identities of 81.3, 89.3 and 94% with T36, VT and SY568, respectively. The 3' UTR had over 97% identity in all isolates, whereas the 5' UTR of T385 had 67% identity with VT, 66.3% with SY568 and only 42.5% with T36. In the coding regions, the nucleotide differences between T385 and VT were evenly distributed along the genome (around 90% identity); this was not observed between T385 and the other isolates. T385 and T36 had nucleotide identities around 90% in the eight 3'-terminal ORFs of the genome, but only 72.3% in ORF 1a, a divergence pattern similar to that reported previously for T36 and VT. T385 and SY568 had nucleotide identities close to 90% in the 5'- and 3'-terminal regions of the genome, whereas the central region had over 99% identity. Our data suggest that the central region in the SY568 genome results from RNA recombination between two CTV genomes, one of which was almost identical to T385. (+info)New defective RNAs from citrus tristeza virus: evidence for a replicase-driven template switching mechanism in their generation. (4/761)
Defective RNAs (D-RNAs) ranging in size from 1968 to 2759 nt were detected in four citrus tristeza virus (CTV) isolates by hybridization of electroblotted dsRNAs with two probes specific for the 5'- and 3'-terminal genomic regions. The RNAs that hybridized with both probes were eluted, cloned and sequenced. Comparison with the sequences of the corresponding genomic regions of the helper virus showed, in all cases, over 99% nucleotide identity and direct repeats of 4-5 nt flanking or in the vicinity of the junction sites. The presence of the repeats from two separate genome locations suggests a replicase-driven template switching mechanism for the generation of these CTV D-RNAs. Two of the CTV isolates that differed greatly in their pathogenicity contained an identical D-RNA, suggesting that it is unlikely that this D-RNA is involved in symptom modulation, which may be caused by another factor. (+info)cDNA sequence and expression of a cold-responsive gene in Citrus unshiu. (5/761)
A cDNA clone encoding a protein (CuCOR19), the sequence of which is similar to Poncirus COR19, of the dehydrin family was isolated from the epicarp of Citrus unshiu. The molecular mass of the predicted protein was 18,980 daltons. CuCOR19 was highly hydrophilic and contained three repeating elements including Lys-rich motifs. The gene expression in leaves increased by cold stress. (+info)Dietary folate from vegetables and citrus fruit decreases plasma homocysteine concentrations in humans in a dietary controlled trial. (6/761)
Elevated total plasma homocysteine (tHcy) concentrations are considered a risk factor for neural tube defects (NTD) and cardiovascular disease. Supplementation with folic acid decreases the risk of women having children with NTD. In both sexes, it decreases tHcy levels. We investigated the efficacy of natural dietary folate in improving folate and homocysteine status. We performed a 4-wk dietary controlled, parallel design intervention trial with 66 healthy subjects (18-45 y) divided into 3 treatment groups: the dietary folate group, the folic acid group and the placebo group. Each day each group was fed a different diet. The dietary folate group received a diet high in vegetables and citrus fruit (total folate content approximately 560 microgram) plus a placebo tablet. The folic acid group received a diet naturally low in folate (approximately 210 microgram) plus 500 microgram folic acid and placebo tablet on alternate days, i.e., 250 microgram folic acid/d. And the placebo group received the same low-folate diet as the folic acid group plus a placebo tablet. After 4 wk of intervention, folate status improved, and tHcy concentrations decreased in both the dietary folate and the folic acid groups. From the amount of additional folate (350 microgram/d) and folic acid (250 microgram/d) consumed, the relative bioavailability of dietary folate compared to folic acid was calculated to be 60-98%, depending on the endpoint used. In conclusion, increasing the consumption of vegetables and citrus fruit, both good sources of folate, will improve folate status and decrease tHcy concentrations. This may contribute to the prevention of cardiovascular disease and NTD in the general population (+info)Plasma and hepatic cholesterol and hepatic activities of 3-hydroxy-3-methyl-glutaryl-CoA reductase and acyl CoA: cholesterol transferase are lower in rats fed citrus peel extract or a mixture of citrus bioflavonoids. (7/761)
The cholesterol-lowering effects of tangerine peel extract and a mixture of two citrus flavonoids were tested. Male rats were fed a 1 g/100 g high-cholesterol diet for 42 d with supplements of either tangerine-peel extract or a mixture of naringin and hesperidin (0.5 g/100 g) to study the effects of plasma and hepatic lipids, hepatic enzyme activities, and the excretion of fecal neutral sterols. Both the tangerine-peel extract and mixture of two flavonoids significantly lowered the levels (mean +/- SE) of plasma (2.44 +/- 0. 59 and 2.42 +/- 0.31 mmol/L, vs. 3.80 +/- 0.28 mmol/L, P < 0.05), hepatic cholesterol (0.143 +/- 0.017 and 0.131 +/- 0.010 mmol/g vs. 0.181 +/- 0.003 mmol/g, P < 0.05), and hepatic triglycerides (0.069 +/- 0.007 and 0.075 +/- 0.006 mmol/g vs. 0.095 +/- 0.002 mmol/g, P < 0.05) compared to those of the control. The 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase (1565.0 +/- 106. 0 pmol. min-1. mg protein-1 and 1783.0 +/- 282 pmol. min-1. mg protein-1 vs. 2487.0 +/- 210.0 pmol. min-1. mg protein-1, P < 0.05) and acyl CoA: cholesterol O-acyltransferase (ACAT) activities (548.0 +/- 65.0 and 615.0 +/- 80.0 pmol. min-1. mg protein-1 vs. 806.0 +/- 105.0 pmol. min-1. mg protein-1, P < 0.05) were significantly lower in the experimental groups than in the control. These supplements also substantially reduced the excretion of fecal neutral sterols compared to the control (211.1 +/- 26.7 and 208.2 +/- 31.6 mg/d vs. 521.9 +/- 53.9 mg/d). The inhibition of HMG-CoA reductase and ACAT activities resulting from the supplementation of either tangerine-peel extract or a combination of its bioflavonoids could account for the decrease in fecal neutral sterol that appears to compensate for the decreased cholesterol biosynthesis in the liver. (+info)Implicit testing of odor memory: instances of positive and negative repetition priming. (8/761)
The study provides a test and evaluation of a new repetition priming procedure designed to solve problems in investigating olfactory-specific priming. Although the results did not reveal any overall priming effect, a post-hoc analysis showed that incorrectly identified odors were more quickly processed than control odors, whereas correctly identified odors were processed more slowly These results are discussed and interpreted as instances of positive and negative repetition priming respectively. (+info)'Citrus' is a genus of flowering plants in the rue family, Rutaceae. It includes several species of shrubs and trees that produce fruits known as citrus fruits. Some common examples of citrus fruits are oranges, lemons, limes, grapefruits, and pomelos. These fruits are popular for their juicy pulp and fragrant zest, which are used in a wide variety of culinary applications around the world.
Citrus fruits are also known for their high vitamin C content and other health benefits. They contain various bioactive compounds such as flavonoids and carotenoids, which have antioxidant properties and may help protect against chronic diseases like cancer and cardiovascular disease. Additionally, citrus fruits are a good source of dietary fiber, which can aid in digestion and help regulate blood sugar levels.
In medical terms, citrus fruits may be recommended as part of a healthy diet to help prevent nutrient deficiencies and promote overall health. However, it's important to note that some people may have allergies or sensitivities to citrus fruits, which can cause symptoms like mouth irritation, hives, or anaphylaxis in severe cases. Additionally, citrus fruits can interact with certain medications, so it's always a good idea to consult with a healthcare provider before making any significant changes to your diet.
'Citrus sinensis' is the scientific name for the fruit species more commonly known as sweet oranges. These are popular fruits that belong to the Rutaceae family and have originated in Southeast Asia. Sweet oranges are widely cultivated and consumed all over the world, both fresh and as juice. They have a sweet taste and juicy pulp, enclosed in a thick and fragrant orange-colored peel. Some well-known varieties of 'Citrus sinensis' include Navel, Valencia, and Blood oranges.
A closterovirus is a type of virus that primarily infects plants. These viruses are characterized by their long, flexuous (flexible) filamentous particles, which can be up to several thousand nanometers in length. Closteroviruses have a positive-sense single-stranded RNA genome and are transmitted by insect vectors, such as aphids.
Closteroviruses infect a wide range of plants, including important crops like citrus, beet, and grapevines. They can cause various symptoms in infected plants, such as stunting, leaf yellowing, and reduced yield. Some closteroviruses also have satellite RNAs or associated viruses that can affect the severity of the disease.
Examples of closteroviruses include citrus tristeza virus (CTV), beet yellows virus (BYV), and grapevine leafroll-associated virus 3 (GLRaV-3). Due to their economic importance, closteroviruses have been extensively studied, and significant efforts have been made to develop control strategies for these viruses.
Hesperidin is a flavonoid, specifically a type of flavanone glycoside, that is commonly found in citrus fruits such as oranges, lemons, and grapefruits. It is particularly abundant in the peel and membranes of these fruits. Hesperidin has been studied for its potential health benefits, including its antioxidant, anti-inflammatory, and cardiovascular protective properties. However, more research is needed to fully understand its effects and potential therapeutic uses.
'Citrus paradisi' is the scientific name for a citrus fruit also known as the grapefruit. Grapefruits are a hybrid of pomelo and orange, believed to have originated in Barbados in the 18th century. They are known for their tangy, slightly bitter taste and juicy pulp.
Grapefruits are popular for their nutritional benefits as they are high in vitamin C, fiber, and antioxidants like lycopene and flavonoids. Some studies suggest that consuming grapefruit may help with weight loss, reduce the risk of certain cancers, and improve heart health. However, it's important to note that grapefruits can interact with certain medications, so it's always best to consult with a healthcare provider before adding them to your diet if you are taking medication.
A plant disease is a disorder that affects the normal growth and development of plants, caused by pathogenic organisms such as bacteria, viruses, fungi, parasites, or nematodes, as well as environmental factors like nutrient deficiencies, extreme temperatures, or physical damage. These diseases can cause various symptoms, including discoloration, wilting, stunted growth, necrosis, and reduced yield or productivity, which can have significant economic and ecological impacts.
Rhizobiaceae is a family of bacteria that have the ability to fix nitrogen. These bacteria are gram-negative, motile, and rod-shaped. They are commonly found in the root nodules of leguminous plants, where they form a symbiotic relationship with the plant. The bacteria provide the plant with fixed nitrogen, while the plant provides the bacteria with carbon and a protected environment.
The most well-known genus of Rhizobiaceae is Rhizobium, which includes several species that are important for agriculture because of their ability to fix nitrogen in the root nodules of legumes. Other genera in this family include Bradyrhizobium, Mesorhizobium, and Sinorhizobium.
It's worth noting that while Rhizobiaceae bacteria are generally beneficial, they can sometimes cause disease in plants under certain conditions. For example, some strains of Rhizobium can cause leaf spots on certain crops.
'Citrus aurantiifolia' is the scientific name for a species of citrus fruit known as Key lime or Mexican lime. It is a small, thorny evergreen tree that typically grows to around 5 meters in height. The fruit of this tree is small and round, with a green, thin, and wrinkled skin that turns yellow when ripe. The interior of the fruit is juicy, tart, and aromatic, making it popular for use in various culinary applications, particularly in the preparation of Key lime pie.
The Key lime is native to Southeast Asia but was brought to the Americas by Spanish explorers in the 16th century. It is now widely cultivated in tropical and subtropical regions around the world, including Florida and Mexico, where it is a significant commercial crop. The Key lime tree is also valued for its attractive flowers and decorative foliage.
I'm sorry for any confusion, but "fruit" is not a medical term per se. It is a common term used to describe the part of a plant that develops from the ovary after flowering and contains seeds. However, in a nutritional or dietary context, "fruits" are often referred to as foods that are typically sweet and juicy, and come from plants' flowers. They are rich in fiber, vitamins, and minerals, making them an essential part of a healthy diet. But in a strict medical sense, there isn't a specific definition for "fruit."
"Poncirus" is a genus of small, spiny trees or shrubs that belong to the family Rutaceae. While it is not a medical term, it is commonly found in the field of botany. The most common species is "Poncirus trifoliata," also known as the hardy orange or trifoliate orange. This plant is native to China and Japan and is often used in horticulture for its hardiness and attractive flowers and fruit. Although the fruits and leaves have been used in traditional medicine in some cultures, there is limited scientific evidence supporting their medicinal use.
Flavones are a type of flavonoid, which is a class of plant and fungal metabolites. They are characterized by a phenylbenzopyrone structure, consisting of two benzene rings (A and B) linked through a heterocyclic pyrone ring (C). Flavones specifically have a double bond between the second and third carbon atoms in the C ring, which contributes to their planar structure.
Flavones are found in various plants, including fruits, vegetables, and herbs, and they have been studied for their potential health benefits. Some common flavones include luteolin, apigenin, and chrysin. These compounds have been shown to have antioxidant, anti-inflammatory, and anticancer properties in laboratory studies, but more research is needed to determine their effectiveness and safety in humans.
Limonin is not a medical term, but a chemical compound found in various plants, including citrus fruits. It is a type of limonoid, which is a class of naturally occurring compounds that are known for their bitter taste and potential health benefits. Specifically, limonin is found in the seeds and membranes of citrus fruits such as oranges, lemons, and grapefruits.
Limonin has been studied for its potential medicinal properties, including its antioxidant, anti-inflammatory, and chemopreventive effects. However, more research is needed to fully understand its mechanisms of action and potential health benefits in humans. It's important to note that while limonin may have potential health benefits, it should not be used as a substitute for medical treatment or advice from a healthcare professional.
"Xanthomonas axonopodis" is a gram-negative, rod-shaped bacterium that belongs to the family Xanthomonadaceae. It is a plant pathogen that causes various diseases in a wide range of host plants, including crops such as cotton, beans, and pepper. The bacterium enters the plant through wounds or natural openings and multiplies within the plant tissue, causing symptoms such as leaf spots, stem cankers, and wilting. Some strains of X. axonopodis can also cause disease in humans, although this is rare. It is typically treated with copper-based bactericides or antibiotics.
Cyclohexenes are organic compounds that consist of a six-carbon ring (cyclohexane) with one double bond. The general chemical formula for cyclohexene is C6H10. The double bond can introduce various chemical properties and reactions to the compound, such as electrophilic addition reactions.
Cyclohexenes are used in the synthesis of other organic compounds, including pharmaceuticals, agrochemicals, and materials. Some cyclohexene derivatives also occur naturally, for example, in essential oils and certain plant extracts. However, it is important to note that pure cyclohexene has a mild odor and is considered a hazardous substance, with potential health effects such as skin and eye irritation, respiratory issues, and potential long-term effects upon repeated exposure.
Volatile oils, also known as essential oils, are a type of organic compound that are naturally produced in plants. They are called "volatile" because they evaporate quickly at room temperature due to their high vapor pressure. These oils are composed of complex mixtures of various compounds, including terpenes, terpenoids, aldehydes, ketones, esters, and alcohols. They are responsible for the characteristic aroma and flavor of many plants and are often used in perfumes, flavors, and aromatherapy. In a medical context, volatile oils may have therapeutic properties and be used in certain medications or treatments, but it's important to note that they can also cause adverse reactions if not used properly.
Xanthomonas is a genus of Gram-negative, rod-shaped bacteria that are widely distributed in various environments, including water, soil, and plant surfaces. They are known to cause diseases in plants, such as black rot in crucifers, bacterial spot in tomatoes and peppers, and citrus canker in citrus trees. Some species of Xanthomonas can also infect humans, although this is relatively rare. Infections in humans typically occur through contact with contaminated water or soil, and can cause various symptoms such as pneumonia, skin infections, and bloodstream infections. However, it's important to note that Xanthomonas species are not typically associated with human diseases and are mainly known for their impact on plants.
Viroids are the smallest known pathogens that can infect plants. They are similar to viruses in that they consist of nucleic acid, but unlike viruses, viroids do not contain protein and are not encapsidated within a protective coat. Instead, viroids are simply small, naked circles of RNA that can replicate inside plant cells by using the host's enzymes.
Viroids can cause various diseases in plants, such as stunting, leaf distortion, and reduced yield. They can be transmitted through seed, vegetative propagation, or mechanical means, such as grafting or pruning tools. Because of their small size and simple structure, viroids are difficult to detect and control, making them a significant challenge in plant pathology.
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.
I'm sorry for any confusion, but "Hemiptera" is not a medical term. It is a taxonomic order in the classification of living things, also known as "true bugs." This group includes species such as cicadas, aphids, and bedbugs. If you have a medical term in mind, please provide it so I can give you an accurate definition.
Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. They are major components of many essential oils found in plants, giving them their characteristic fragrances and flavors. Monoterpenes can be further classified into various subgroups based on their structural features, such as acyclic (e.g., myrcene), monocyclic (e.g., limonene), and bicyclic (e.g., pinene) compounds. In the medical field, monoterpenes have been studied for their potential therapeutic properties, including anti-inflammatory, antimicrobial, and anticancer activities. However, more research is needed to fully understand their mechanisms of action and clinical applications.