American
Society of Plant Biologists
Northeast 5ection
66th Annual
Meeting
P34 Phenolic Cycle in Plants and Their Environment.
Kefeli V., Kalevitch M.*, Borsari B.**
Slippery Rock Watershed Coalition, Slippery Rock, PA 16057,
* Robert Morris University, Moon Township, PA
** Slippery Rock University
Slippery
Rock, PA 16057
Phenolic substances
participate in oxidative processes (phenolic acids), may favor insect
attraction (flavonoids), inhibit plants growth (coumarins) or enhance
immunity relations (phytoalexins) and differentiation (lignin). The
purpose of this study is to illustrate the cycling of these molecules
in ecosystems, while seeking a better understanding of their fate within
soils. Plant organs dispose phenolic substances at the completion of
ontogenesis that become metabolized by microorganisms (bacteria and
fungi). Components of phenolic molecules become incorporated in soil
humus (probably as a result of microbial activity) and they may induce
new plant growth, via the root system. The greening of seedlings is
accompanied by phenolic substances present in chloroplasts. Extensive
experimentation with the isolated chloroplasts of willow (Salix rubra)
demonstrated the presence of chalcon isosalipurposide in the intact
and split chloroplasts. In leaves of albino cotton (Gossypium hirsurum)
seedlings, in which photosynthesis does not take place, phenolics were
detected. A plausible reason to explain their presence may derive from
phenylalanine contained in the seed cotyledons. Fungi are able to split
flavonoids from composted red maple (Acer rubrum) leaves. These
brown, heavy molecules compared to phenolic substances are clearly detectable
through chromatography.
May 3 - 4, 2002
Wellesley College
Wellesley, Massachusetts