Frost Resistance
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Frost Resistance
Frost resistance is the ability of plants to survive cold temperatures. Generally, land plants of the northern hemisphere have higher frost resistance than those of the southern hemisphere. An example of a frost resistant plant is '' Drimys winteri'' which is more frost-tolerant than naturally occurring conifers and vessel-bearing angiosperms such as the '' Nothofagus'' that can be found in its range in southern South America. The physiological process of cold acclimatization is induced in fall and early winter by low above- zero temperatures (cold) and includes complex reprogramming of the cellular environment to induce enhanced frost tolerance. Temperate climate fruit trees reach their highest resistance in the middle of winter. Since freezing belongs to dehydration stresses, cold acclimation process is associated with an enhanced accumulation of osmolytes ( sugars, proline, polyamines, and hydrophilic proteins). The loss of frost resistance occurs after warming. Rapid tempe ...
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Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's North Pole. Owing to Earth's axial tilt of 23.439281°, winter in the Northern Hemisphere lasts from the December solstice (typically December 21 UTC) to the March equinox (typically March 20 UTC), while summer lasts from the June solstice through to the September equinox (typically on 23 September UTC). The dates vary each year due to the difference between the calendar year and the astronomical year. Within the Northern Hemisphere, oceanic currents can change the weather patterns that affect many factors within the north coast. Such events include El Niño–Southern Oscillation. Trade winds blow from east to west just above the equator. The winds pull surface water with them, creating currents, which flow westward due to the Coriolis e ...
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Dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mild dehydration can also be caused by immersion diuresis, which may increase risk of decompression sickness in divers. Most people can tolerate a 3-4% decrease in total body water without difficulty or adverse health effects. A 5-8% decrease can cause fatigue and dizziness. Loss of over ten percent of total body water can cause physical and mental deterioration, accompanied by severe thirst. Death occurs at a loss of between fifteen and twenty-five percent of the body water.Ashcroft F, Life Without Water in Life at the Extremes. Berkeley and Los Angeles, 2000, 134-138. Mild dehydration is characterized by thirst and general discomfort and is usually resolved with oral rehydration. Dehydration can cause hypernatremia (high levels of sodium ...
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Peach
The peach (''Prunus persica'') is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, non-fuzzy varieties), nectarines. The specific name ''persica'' refers to its widespread cultivation in Persia (modern-day Iran), from where it was transplanted to Europe. It belongs to the genus ''Prunus'', which includes the cherry, apricot, almond, and plum, in the rose family. The peach is classified with the almond in the subgenus '' Amygdalus'', distinguished from the other subgenera by the corrugated seed shell (endocarp). Due to their close relatedness, the kernel of a peach stone tastes remarkably similar to almond, and peach stones are often used to make a cheap version of marzipan, known as persipan. Peaches and nectarines are the same species, though they are regarded commercially as different fruits. The skin of nectarines lac ...
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Apricot
An apricot (, ) is a fruit, or the tree that bears the fruit, of several species in the genus ''Prunus''. Usually, an apricot is from the species '' P. armeniaca'', but the fruits of the other species in ''Prunus'' sect. ''Armeniaca'' are also called apricots. Etymology ''Apricot'' first appeared in English in the 16th century as ''abrecock'' from the Middle French ''aubercot'' or later ''abricot'', from Spanish '' albaricoque'' and Catalan ''a(l)bercoc'', in turn from Arabic الْبَرْقُوق (al-barqūq, "the plums"), from Byzantine Greek βερικοκκίᾱ (berikokkíā, "apricot tree"), derived from late Greek ''πραικόκιον'' (''praikókion'', "apricot") from Latin '' ersica ("peach")praecocia'' (''praecoquus'', "early ripening"). Species Apricots are species belonging to ''Prunus'' sect. ''Armeniaca''. The taxonomic position of '' P. brigantina'' is disputed. It is grouped with plum species according to chloroplast DNA sequences, but more closely r ...
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Proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residues ...
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Hydrophile
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are not attracted to water and may seem to be repelled by it. Hygroscopics ''are'' attracted to water, but are not dissolved by water. Molecules A hydrophilic molecule or portion of a molecule is one whose interactions with water and other polar substances are more thermodynamically favorable than their interactions with oil or other hydrophobic solvents. They are typically charge-polarized and capable of hydrogen bonding. This makes these molecules soluble not only in water but also in other polar solvents. Hydrophilic molecules (and portions of molecules) can be contrasted with hydrophobic molecules (and portions of molecules). In some cases, both hydrophilic and hydrophobic properties occur in a single molecule. An example of these amphiph ...
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Polyamine
A polyamine is an organic compound having more than two amino groups. Alkyl polyamines occur naturally, but some are synthetic. Alkylpolyamines are colorless, hygroscopic, and water soluble. Near neutral pH, they exist as the ammonium derivatives. Most aromatic polyamines are crystalline solids at room temperature. Natural polyamines Low-molecular-weight linear polyamines are found in all forms of life. The principal examples are the triamine spermidine and the tetraamine spermine. They are structurally and biosynthetically related to the diamines putrescine and cadaverine. Polyamine metabolism is regulated by the activity of the enzyme ornithine decarboxylase (ODC). Polyamines are found in high concentrations in the mammalian brain. File:Spermidine-2D-skeletal.svg, spermidine File:Spermine.svg, spermine Synthetic polyamines Several synthetic polyamines are used in chemical industry and the research laboratory. They are mainly of interest as additives to motor oil and as co-rea ...
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Proline
Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group but is rather a secondary amine. The secondary amine nitrogen is in the protonated form (NH2+) under biological conditions, while the carboxyl group is in the deprotonated −COO− form. The "side chain" from the α carbon connects to the nitrogen forming a pyrrolidine loop, classifying it as a aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it from the non-essential amino acid L-glutamate. It is encoded by all the codons starting with CC (CCU, CCC, CCA, and CCG). Proline is the only proteinogenic secondary amino acid which is a secondary amine, as the nitrogen atom is attached both to the α-carbon and to a chain of three carbons that together form a five-membered ring. History and etymology Proline was first isolated in 1900 by Richard Willstätter who obtained the amino ...
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Sugars
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two molecules of glucose). White sugar is a refined form of sucrose. In the body, compound sugars are hydrolysed into simple sugars. Longer chains of monosaccharides (>2) are not regarded as sugars, and are called oligosaccharides or polysaccharides. Starch is a glucose polymer found in plants, the most abundant source of energy in human food. Some other chemical substances, such as glycerol and sugar alcohols, may have a sweet taste, but are not classified as sugar. Sugars are found in the tissues of most plants. Honey and fruits are abundant natural sources of simple sugars. Sucrose is ...
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Osmolytes
Osmolytes are low-molecular weight organic compounds that influence the properties of biological fluids. Their primary role is to maintain the integrity of cells by affecting the viscosity, melting point, and ionic strength of the aqueous solution. When a cell swells due to external osmotic pressure, membrane channels open and allow efflux of osmolytes which carry water with them, restoring normal cell volume. Osmolytes also interact with the constituents of the cell, e.g. they influence protein folding. Common osmolytes include amino acids, sugars and polyols, methylamines, methylsulfonium compounds, and urea. Case studies Natural osmolytes that can act as osmoprotectants include trimethylamine ''N''-oxide (TMAO), dimethylsulfoniopropionate, sarcosine, betaine, glycerophosphorylcholine, myo-inositol, taurine, glycine, and others. Remarkably, TMAO has the capacity to restore glucocorticoid binding to mutant receptors. Bacteria accumulate osmolytes for protection against a high ...
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Folia Horticulturae
''Folia Horticulturae'' is a quarterly peer-reviewed open access scientific journal of the Polish Society of Horticultural Science publishing original research papers, short communications and review papers from all branches of horticulture. Works must cover the subject of one of the main branches of horticultural crops: fruit production, vegetable production, herbs and medicinal plants, ornamental plants, and plants used in landscape architecture, as well as papers that combine aspects of plant cultivation, plant protection, breeding, seed and nursery, and storage of horticultural commodities. The journal is abstracted and indexed in AGRICOLA, CABI, and EBSCO databases EBSCO Information Services, headquartered in Ipswich, Massachusetts, is a division of EBSCO Industries Inc., a private company headquartered in Birmingham, Alabama. EBSCO provides products and services to libraries of very many types around the .... According to the '' Journal Citation Reports'', the jour ...
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