ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
The distribution of 4 key isoflavones (luteone, genistein, 2′-hydroxygenistein and wighteone) in lupin (Lupinus albus L. cv. multolupa) hypocotyls shows a gradient that diminishes from young to old tissues. A spatial gradient occurs within the hypocotyl, and a temporal gradient in both the outermost vascular and epidermal tissues. Not only does a gradient exist in respect to the quantity of isoflavones, but there is also a gradient in respect to the type of isoflavone. Thus, wighteone is mainly associated with the non-meristematic zones of the lupin hypocotyl. A close relationship was found between the distribution and the localization in the walls of phloem cells of both peroxidase (EC 1.11.1.7) and isoflavones. This observation suggests an in vivo peroxidase-isoflavone interconnection. In fact, lupin isoflavones are able to inhibit the peroxidase-catalyzed oxidation of the lignin precursor coniferyl alcohol, probably due to the co-oxidation of isoflavones in the reaction media. The results are discussed on the basis of a possible role for isoflavones in controlling cell wallperoxidase activity involved in the lignification of phloem cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1990.tb00033.x
