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Distribution of isoflavones in lupin hypocotyls. Possible control of cell wall peroxidase activity involved in lignification
Author(s) -
Ferrer M. Angeles,
Pedreño M. Angeles,
Calderón Antonio A.,
Muñoz Romualdo,
Barceló Alfonso
Publication year - 1990
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1990.tb00033.x
Subject(s) - isoflavones , hypocotyl , genistein , peroxidase , phloem , chemistry , biochemistry , formononetin , botany , biology , daidzein , enzyme , endocrinology
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.