Hormones plant

Ethylene occurs naturally in small amounts as a plant hormone Hormones are substances that act as messengers to regulate biological processes Ethylene IS involved in the ripening of many fruits in which it IS formed in a complex series of steps from a com pound containing a cyclopropane ring... 

For a review see Ethylene—An Unusual Plant Hormone in the April 1992 issue of the Journal of Chemical Education (pp 315-318)... 

J. W. MitcheU and G. A. Livingston, Methods of Studying Plant Hormones and Growth-Regulating Substances, Agriculture Handbook No. 336, USD A,... 

N. Takahashi, ed., Chemisty of Plant Hormones, CRC Press, Boca Raton, Fla., 1986. 

A. Cro2ier andj. R. Hillman, eds.. The Biosynthesis and Metabolism of Plant Hormones, Oxford University Press, Oxford, U.K., 1984. 

An alkene, sometimes caJled an olefin, is a hydrocarbon that contains a carbon-carbon double bond. Alkenes occur abundantly in nature. Ethylene, for instance, is a plant hormone that induces ripening in fruit, and o-pinene is the major component of turpentine. Life itself would be impossible without such alkenes as /3-carotene, a compound that contains 11 double bonds. An orange pigment responsible for the color of carrots, /3-carotene is a valuable dietary source of vitamin A and is thought to offer some protection against certain types of cancer. 

Ethene is used to make a host of organic compounds it is also the starting material for the preparation of polyethylene (Chapter 23). Since it is a plant hormone, ethene finds application in agriculture. It is used to ripen fruit that has been picked green to avoid spoilage in shipping. Exposure to ethene at very low concentrations produces the colors we associate with ripe bananas and oranges. 

The phenomenon of leaf and fruit drop is known as abscission and has been suspected for some time to be under hormonal control. Dr. Addicott s description of the structure and properties of Abscisin II, the abscission hormone isolated from cotton, climaxes over 12 years of his own investigations on the subject and represents perhaps the greatest advance in plant hormone research in the past decade. It also provides an unusual and unsuspected structural model to guide... 

Abscisin II is a plant hormone which accelerates (in interaction with other factors) the abscission of young fruit of cotton. It can accelerate leaf senescence and abscission, inhibit flowering, and induce dormancy. It has no activity as an auxin or a gibberellin but counteracts the action of these hormones. Abscisin II was isolated from the acid fraction of an acetone extract by chromatographic procedures guided by an abscission bioassay. Its structure was determined from elemental analysis, mass spectrum, and infrared, ultraviolet, and nuclear magnetic resonance spectra. Comparisons of these with relevant spectra of isophorone and sorbic acid derivatives confirmed that abscisin II is 3-methyl-5-(1-hydroxy-4-oxo-2, 6, 6-trimethyl-2-cyclohexen-l-yl)-c s, trans-2, 4-pen-tadienoic acid. This carbon skeleton is shown to be unique among the known sesquiterpenes. 

Maksimov I. V. Yarullina L. G. (2007) Salycilic acid and local resistance to pathogens / / Salycilic acid a plant hormone, Springer-Verlag. Berlin. Heidelberg. P. 323 - 334. 

The biosynthesis and metabolism of plant hormones. Edited by A. Crozier and J.R. Hillman... 

Engelsma, G. In "Regulation of Secondary Product and Plant Hormone Metabolism" Luckner, M. Schreiber, K., Eds. Pergamon New York, 1979 pp. 163-72. 

Department of Chemistry, University of Maryland, College Park, MD 20742 Plant Hormone Laboratory, U.S. Department of Agriculture, Beltsville, MD 20705... 

In view of the great agricultural importance today of the synthetic plant growth substances in controlling the growth of plants of economic importance, details of the history of this development of investigations on plant hormones are presented. 

Ethene is produced naturally by fruits such as tomatoes and bananas as a plant hormone for the ripening process of these fruits. 

---