Research Paper

Leaf surface secretion of flavonoids in Myricaria bracteata and M. longifolia (Tamaricaceae)

Evgeniya A. Karpova, Alexander A. Krasnikov, Elena M. Lyakh, Alexander A. Chernonosov

Published on: 03 August 2022

Page: 413 - 421

DOI: 10.6165/tai.2022.67.413

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2022 vol.67 no.3 pp.413-421

Abstract

Flavonoids of the salt glands and tissues of Myricaria bracteata and Myricaria longifolia were studied by histochemical assays and chromatographic analysis. Histochemical staining indicated flavonoid accumulation in the salt glands, within vascular bundles, and in subepidermal parenchyma layers of the leaves. Exudate flavonoids of the leaves were characterized for the first time. Phenolic profiles of these species proved to be similar and showed high levels of ellagic acid and total flavonoids, including hyperoside, isoquercitrin, astragalin, avicularin, isorhamnetin 3-O-rutinoside, quercetin, naringenin, and luteolin. Astragalin and hyperoside are major phenolic compounds in the leaves. The latter were found to constitute ~0.2−0.3% of total phenolics of the leaves; meanwhile, exudate flavonoids make up ~0.5% of total flavonoids. The high similarity of phenolic composition between the whole-leaf extracts and the exudates indicates the homogeneous origin of these compounds. The observed tissue distribution of flavonoids and their presence in the salt glands confirm the role of these glands in leaf surface secretion of flavonoids.

Keyword: Myricaria, Tamaricaceae, leaf exudate, salt glands, flavonoids

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