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Genetically Modified Tomato
A genetically modified tomato, or transgenic tomato, is a tomato that has had its genes modified, using genetic engineering. The first trial genetically modified food was a tomato engineered to have a longer shelf life (the Flavr Savr), which was on the market briefly beginning on May 21, 1994. The first direct consumption tomato was approved in Japan in 2021. Primary work is focused on developing tomatoes with new traits like increased resistance to pests or environmental stresses. Other projects aim to enrich tomatoes with substances that may offer health benefits or be more nutritious. As well as aiming to produce novel crops, scientists produce genetically modified tomatoes to understand the function of genes naturally present in tomatoes. Wild tomatoes are small, green and largely unappetizing, but after centuries of breeding there are now thousands of varieties grown worldwide. Agrobacterium-mediated genetic engineering techniques were developed in the late 1980s that coul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomatoes ARS
The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word , from which the English word ''tomato'' derived. Its domestication and use as a cultivated food may have originated with the indigenous peoples of Mexico. The Aztecs used tomatoes in their cooking at the time of the Spanish conquest of the Aztec Empire, and after the Spanish encountered the tomato for the first time after their contact with the Aztecs, they brought the plant to Europe, in a widespread transfer of plants known as the Columbian exchange. From there, the tomato was introduced to other parts of the European-colonized world during the 16th century. Tomatoes are a significant source of umami flavor. They are consumed in diverse ways: raw or cooked, and in many dishes, sauces, salads, and drinks. While tomatoes are fruits—bota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromoplast
Chromoplasts are plastids, heterogeneous organelles responsible for pigment synthesis and storage in specific photosynthetic eukaryotes. It is thought that like all other plastids including chloroplasts and leucoplasts they are descended from symbiotic prokaryotes. Function Chromoplasts are found in fruits, flowers, roots, and stressed and aging leaves, and are responsible for their distinctive colors. This is always associated with a massive increase in the accumulation of carotenoid pigments. The conversion of chloroplasts to chromoplasts in ripening is a classic example. They are generally found in mature tissues and are derived from preexisting mature plastids. Fruits and flowers are the most common structures for the biosynthesis of carotenoids, although other reactions occur there as well including the synthesis of sugars, starches, lipids, aromatic compounds, vitamins, and hormones. The DNA in chloroplasts and chromoplasts is identical. One subtle difference in DNA wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomato Paste
Tomato paste is a thick paste made by cooking tomatoes for several hours to reduce the water content, straining out the seeds and skins, and cooking the liquid again to reduce the base to a thick, rich concentrate. It is used to impart an intense tomato flavour to a variety of dishes, such as pasta, soups and braised meat. It is used heavily in Italian cultured food. By contrast, tomato purée is a liquid with a thinner consistency than tomato paste, while tomato sauce is even thinner in consistency. History and traditions Tomato paste is traditionally made in parts of Sicily, southern Italy and Malta by spreading out a much- reduced tomato sauce on wooden boards that are set outdoors under the hot August sun to dry the paste until it is thick enough, when it is scraped up and held together in a richly colored, dark ball. Today, this artisan product is harder to find than the industrial version (which is much thinner). Commercial production uses tomatoes with thick pericarp wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNAi
RNA interference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expression by double-stranded RNA, through translational or transcriptional repression. Historically, RNAi was known by other names, including ''co-suppression'', ''post-transcriptional gene silencing'' (PTGS), and ''quelling''. The detailed study of each of these seemingly different processes elucidated that the identity of these phenomena were all actually RNAi. Andrew Fire and Craig C. Mello shared the 2006 Nobel Prize in Physiology or Medicine for their work on RNAi in the nematode worm ''Caenorhabditis elegans'', which they published in 1998. Since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in suppression of desired genes. RNAi is now known as precise, efficient, stable and better than antisense therapy for gene suppression. Antisense RNA produced intracellularly by an expression vector ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are absent in many eukaryotes, including animals, but are present in some other ones like fungi, algae and plants, and in most prokaryotes (except mollicute bacteria). A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters. The composition of cell walls varies between taxonomic group and species and may depend on cell type and developmental stage. The primary cell wall of land plants is composed of the polysaccharides cellulose, hemicelluloses and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae possess cell walls made of glycoproteins and polysaccharides such as carrageenan and agar that are absent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectin
Pectin ( grc, πηκτικός ': "congealed" and "curdled") is a heteropolysaccharide, a structural acid contained in the primary lamella, in the middle lamella, and in the cell walls of terrestrial plants. The principal, chemical component of pectin is galacturonic acid (a sugar acid derived from galactose) which was isolated and described by Henri Braconnot in 1825. Commercially produced pectin is a white-to-light-brown powder, produced from citrus fruits for use as an edible gelling agent, especially in jams and jellies, dessert fillings, medications, and sweets; and as a chemical stabiliser in fruit juices and milk drinks, and as a source of dietary fiber. Biology Pectin is composed of complex polysaccharides that are present in the primary cell walls of a plant, and are abundant in the green parts of terrestrial plants. Pectin is the principal component of the middle lamella, where it binds cells. Pectin is deposited by exocytosis into the cell wall via vesicles produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antisense
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, sense may have slightly different meanings. For example, negative-sense strand of DNA is equivalent to the template strand, whereas the positive-sense strand is the non-template strand whose nucleotide sequence is equivalent to the sequence of the mRNA transcript. DNA sense Because of the complementary nature of base-pairing between nucleic acid polymers, a double-stranded DNA molecule will be composed of two strands with sequences that are reverse complements of each other. To help molecular biologists specifically identify each strand individually, the two strands are usually differentiated as the "sense" strand and the "antisense" strand. An individual strand of DNA is referred to as positive-sense (also positive (+) or simply sense) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformation (genetics)
In molecular biology and genetics, transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s). For transformation to take place, the recipient bacterium must be in a state of competence, which might occur in nature as a time-limited response to environmental conditions such as starvation and cell density, and may also be induced in a laboratory. Transformation is one of three processes that lead to horizontal gene transfer, in which exogenous genetic material passes from one bacterium to another, the other two being conjugation (transfer of genetic material between two bacterial cells in direct contact) and transduction (injection of foreign DNA by a bacteriophage virus into the host bacterium). In transformation, the genetic material passes through the intervening medium, and uptake is completely dependent on the recipient bacterium. As of 2014 about 8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygalacturonase
Endo-polygalacturonase (EC 3.2.1.15, pectin depolymerase, pectolase, pectin hydrolase, and poly-α-1,4-galacturonide glycanohydrolase; systematic name (1→4)-α-D-galacturonan glycanohydrolase (endo-cleaving)) is an enzyme that hydrolyzes the α-1,4 glycosidic bonds between galacturonic acid residues: :(1,4-α-D-galacturonosyl)''n''+''m'' + H2O = (1,4-α-D-galacturonosyl)''n'' + (1,4-α-D-galacturonosyl)''m'' Polygalacturonan, whose major component is galacturonic acid, is a significant carbohydrate component of the pectin network that comprises plant cell walls. Therefore, the activity of the endogenous plant PGs works to soften and sweeten fruit during the ripening process. Similarly, phytopathogens use PGs as a means to weaken the pectin network, so that digestive enzymes can be excreted into the plant host to acquire nutrients. Structure This enzyme's multiple parallel β sheets form a helical shape that is called a β helix. This highly stable structure, thanks to nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climacteric (botany)
Generally, fleshy fruits can be divided into two groups based on the presence or absence of a respiratory increase at the onset of ripening. This respiratory increase—which is preceded, or accompanied, by a rise in ethylene—is called a climacteric, and there are marked differences in the development of climacteric and non-climacteric fruits. Climacteric fruit can be either monocots or dicots and the ripening of these fruits can still be achieved even if the fruit has been harvested at the end of their growth period (prior to ripening on the parent plant). Non-climacteric fruits ripen without ethylene and respiration bursts, the ripening process is slower, and for the most part they will not be able to ripen if the fruit is not attached to the parent plant. Examples of climacteric fruits include apples, bananas, melons, apricots, tomatoes, as well as most stone fruits. Non-climacteric fruits on the other hand include citrus fruits, grapes, and strawberries (However, non-climac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fruit Ripening
Ripening is a process in fruits that causes them to become more palatable. In general, fruit becomes sweeter, less green, and softer as it ripens. Even though the acidity of fruit increases as it ripens, the higher acidity level does not make the fruit seem tarter. This effect is attributed to the Brix-Acid Ratio. Climacteric fruits ripen after harvesting and so some fruits for market are picked green (e.g. bananas and tomatoes). Underripe fruits are also fibrous, not as juicy, and have tougher outer flesh than ripe fruits (see Mouth feel). Eating unripe fruit can lead to stomachache or stomach cramps, and ripeness affects the palatability of fruit. Science 1 Methylcyclopropene is used as a synthetic 127x127px, leftDeveloping fruits produce compounds like alkaloids and tannins. These compounds are antifeedants, meaning that they discourage animals who would eat them while they are still ripening. This mechanism is used to make sure that fruit isn't eaten before the seeds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
