Structural Characteristics and Content of Polyphenolic Compounds in Healthy Organs and Galls Induced by Allodiplosis crassa Kieff. and Jörg (Cecydomyiidae, Diptera) on Geoffroea decorticans (Hook. and Arn.) Burkart (Leguminosae)

Abstract

Chañar (Geoffroea decorticans- Fabaceae) is a tree from South America that is normally infected with galls originated by insects. One of its parasites is Allodiplosis crassa (Cecidomyiidae, Diptera) which produces globular galls with sticky prolongations. Since this plant has medicinal uses in Argentina, its infestation could alter the quality of the plant drug. The surface of insect-induced galls usually contains defensive features such as trichomes, increased hardness and an increase in the content of polyphenolic compounds. The objective of this research is to assess the structural and histochemical features of the gall and to compare the content of polyphenolic metabolites in the gall, in the healthy leaf and in lignified stems of G. decorticans. The methanolic extract from the galls showed the highest amount of polyphenolic and proanthocyanidins and the lowest amount of hydroxycinnamic derivatives and flavonoids compared to the methanolic extract of the leaves. The photographs taken from the external surface of the gall showed that some prolongations have heads. The histochemical analysis showed that the prolongations have a high amount of proanthocyanidins and flavonoids; and that the heads are reactive to Sudan III. These phytochemical and histological characteristics may have a defensive role against harmful fungi and parasites that attack the larvae of the A. crassa. The results of this study show the presence of defensive features in an insect-induced gall of a medicinal plant with potential implications in the pharmacological activity of this species. This is the first report of a histochemical and phytochemical study in G. corticans galls.

Dynamics of Polyphenol Biosynthesis by Calli Cultures, Suspension Cultures and Wild Specimens of the Medicinal Plant Ligaria cuneifolia (Ruiz & Pav.) Tiegh. (Loranthaceae). Analysis of Their Biological Activity

“…HCA were higher in leaves, and were not affected by the phenological stage. These results correlate with those found in Geoffroea decorticans extracts, in which leaves showed higher levels of HCA derivatives when compared to stems [33]. Chapel [16], working with Calluna vulgaris (L.) Hull, reported that the higher amounts of polyphenolic compounds, including HCA, were found in stems and leaves at all phenological stages except during flowering, while no significant differences in PA content were observed among different organs and phenological stages.…”