Plant, naturalized tissues

Although not abundant in quantity, iodine is distributed in rocks, soils, waters, plants, animal tissues, and foodstuffs (3,4). Excepting the possible occurrence of elemental iodine vapor in the air near certain iodine-rich springs, iodine never occurs free in nature. It is always found combined with other elements. 

The biochemical industiy derives its products from two primaiy sources. Natural produces are yielded by plants, animal tissue, and fluids, and obtained via fermentation from bacteria, molds and fungi, and from man imahan cells. Products can also be obtained by recombinant... 

If herbivore attack can lead to reduced food quality of plants, then it seems reasonable that naturally attacked plants should exhibit decreased food quality compared to naturally unattacked ones. On the other hand, there is considerable evidence that herbivores preferentially attack plants or tissues of high food quality Q). In other words, plant food quality can probably act both as a dependent and an independent variable as far as degree of herblvory is concerned. Therefore, conclusions drawn from comparisons of foliage properties of naturally attacked versus naturally unattacked plants are likely to be confounded by the interaction of these two effects. To avoid this problem the following experiments were conducted by subjecting plants to attack by Insects placed on them by the Investigators. 

T ignin is one of the most abundant natural products constituting about one-fourth of the woody tissue in plants. Nature has chosen a unique synthetic technique to prepare this cross-linked polymeric material from coniferyl alcohol and related substances. The mechanism of lignin formation is not completely known yet, and the structural characterization of lignin has been only partially successful despite considerable research. 

Stockigt J, Obitz P, Falkenhagen H, Lutterbach R and EndreB S (1995) Natural products and enzymes from plant cell cultures. Plant Cell Tissue Organ Culture 43, 97-109. 

Finally, fermentation of endophytic fungi from higher plants has also been considered for the production of plant natural products. Fungal fermentation is much simpler than plant tissue culture but, at least for paclitaxel, production by fermentation of various Taxus endophytic fungi was lower compared with that of plant cells.35... 

David McCaskill and Rodney Croteau, Strategies for bioengineering the development and metabolism of glandular tissues in plants. Nature Biotechnology, 17 (1999), 31-36. 

Natural vanilla flavor and natural vanillin are in high demand and alternative production routes such as using PTC or microbial systems are being sought [60]. De novo synthesis of vanillin and vanilla plant cells and plant callus tissue are important commercial products biosynthesized by PTC. Alternatively, hair roots of vanilla plant have been used as a biocatalyst to convert the precursor ferulic acid into vanillin [104]. 

A breakthrough occurred, however, in the research on plant natural product biosynthesis when tissue and cell suspension cultures were developed by M.H. Zenk. ° Such cultures easily provided continuously fresh Rauvolfia cell material at kg level in a few weeks in cell culture laboratories where Erlenmeyer flasks were used for cell growth (Figure 2). 

Payen s classic work on cellulose was described in his articles entitled "Study of the Composition of the Natural Tissues of Plants and of Lignin" and "Concerning a Means for Isolating the Elemental Tissue of Wood" which were published in 1838 in Comptes Rendus. Payen treated plant tissues, cotton linters, root tips, and various woods with chemicals, including nitric acid in some instances, followed by extraction with ammonia or alkali, water, and solvents, to obtain a fibrous substance, named cellulose. He demonstrated that this "elemental" product from plant... 

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