Hormone ethylene

B. Jackson J. E. Summers L. A. C. J. Voesenek, Potamogeton Pectinatus A Vascular Plant that Makes No Ethylene. In Biology and Biotechnology of the Plant Hormone Ethylene A. K. Kanellis, C. Chang, H. Kende, D. Grierson, Eds. Kluwer Academic Publishers Netherlands, 1997. 

Farmer, 2001). Even nectar production may be effected by such hormones (Heil et al, 2001). The gaseous hormone ethylene plays an important role in plant development, but also in defense (Mattoo and Suttle, 1991). Upon perception of a pathogen, plants show enhanced ethylene production, which has been shown to be involved in the induction of defense reactions (Boiler, 1991). Wild tobacco plants engineered with an Arabidopsis sp. ethylene-insensitive gene do not show typical leaf development arrestment in the presence of leaves of other tobacco plants, demonstrating the importance of ethylene in plant development (Knoester et al.,... 

Boiler, T. (1991). Ethylene in pathogenesis and disease resistance. In The Plant Hormone Ethylene, eds. A. K. Matoo and J. C. Suttle, pp. 293-314. Boca Raton, FL CRC Press. 

Cyclization. A second kind of reaction is represented by the conversion of S-adenosylmethionine to aminocyclopropanecarboxylic acid, a precursor to the plant hormone ethylene (see Chapter 24).159 The quinonoid intermediate cyclizes with elimination of methylthioadenosine to give a Schiff base of the product (Eq. 14-27).160-161a The cyclization step appears to be a simple SN2-like reaction.162... 

Some common plant hormones. All of these hormones are low-molecular-weight compounds. One hormone, ethylene, is a gas. 

Hamilton, A.J., Lycett, G.W. Grierson, D. (1990). Antisense gene that inhibits synthesis of the hormone ethylene in transgenic plants. Nature 346, 284-7. 

Hormones are chemicals made by plants and animals. Hormones control living processes. The ripening of fruit is a process controlled by hormones. Ethylene gas is a hormone made by fruits while they are ripening. 

But chrysanthemic acid derivatives are by far not the only examples of cyclopropane-containing structures in nature. In fact, the highly strained three-membered carbocycle is virtually ubiquitous. It occurs, for example, in every green plant in the form of 1-aminocyclopropanecarboxylic acid (ACC) 2, a direct precursor to the plant hormone ethylene [3]. In addition, the cyclopropane unit is found in a variety of other natural products, inter alia in terpenes and in various cyclopropanated fatty acids [4]. The biochemical precursors of the latter are unsaturated fatty acids, and in view of the existence of polyunsaturated fatty... 

Phisalaphong M, Linden JC (1999) Ethylene and methyl jasmonate interaction and binding models for elicited biosynthetic steps of paclitaxel in suspension cultures of Taxus canadensis. In Kanellis AK, Chang C, Klee H, Bleecker AB, Pech JC, Grierson D (eds.) Biology and biotechnology of the plant hormone ethylene. Kluwer Academic Publishers, Dordrecht, p 85... 

G. Capitani, E. Hohenester, L. Feng, P. Storici, J.F. Kirsch, and J.N. Jansonius. 1999. Structure of 1-aminocyclopropane-l-carboxylate synthase, a key enzyme in the biosynthesis of the plant hormone ethylene J. Mol. Biol. 294 745-756. (PubMed)... 

Most of the compounds cited in this introductory section are produced in metabolic processes where the cyclopropane-containing metabolite appears to be the stable end product or secondary product with as yet unobvious metabolic function. However, this is not the case in at least two types of systems, in which cyclopropyl species are key and necessary intermediate structures in high flux metabolic pathways. The first example is the squalene (76) and phytoene (88) biosynthesis where presqualene pyrophosphate (77) and prephytoene pyrophosphate (89) are obligate cyclopropanoid intermediates in the net head-to-head condensations of two farnesyl pyrophosphate (73) or two geranylgeranyl pyrophosphate (66) molecules respectively. The second example is in plant hormone metabolism where C(3) and C(4) of the amino acid methionine are excised as the simple hormone ethylene via intermediacy of 1-aminocyclopropane-l-carboxylic acid (9). Both examples will be discussed in detail in the Section II. 

The simple cyclopropanoid amino acid ACPC (9) is a constituent of many fruits and plant tissues where it serves as the immediate precursor of the plant hormone ethylene (139) That 02-dependent fragmentation is covered in Section III of this chapter. Biosynthesis of ACPC (9) is the issue here. It has long been known that the ethylene... 

Cyclization. A second kind of reachon is represented by the conversion of S-adenosylmethionine to aminocyclopropanecarboxylic acid, a precursor to the plant hormone ethylene (see Chapter 24). ... 

Kacperska, A. Kubacka-Zebalska, M. Curr. Plant Sci. Biotechnol. Agric. (Cellular and Molecular Aspects of the Plant Hormone Ethylene), 1993,16,211-16. 

AdoMet is also a precursor to the plant hormone, ethylene. A similar mechanism is probably involved in making rare fatty acids containing a cyclopropane ring. 

Both these compounds, 143a and b, needed to investigate the mechanism of biosynthesis of the plant growth hormone ethylene, have been prepared according to the reaction scheme in equation 6599. 144a and b have been prepared by reduction of unlabelled or deuterated ethyl bromoacetate with lithium aluminium deuteride-anhydrous aluminium chloride. Subsequently, 143a and 143b have been synthesized with 4-methylbenzene-... 

---