Ellagitannins: defences of Betula nana against Epirrita autumnata folivory?

Abstract

1 The induced resistance of the subarctic mountain birch Betula pubescens ssp. czerepanovii is a well-characterized phenomenon, whereas the induced responses of Betula nana L., one of the parental species of mountain birch, have not yet been characterized. Betula nana is more resistant to several classes of insectivorous herbivores than the mountain birch, although the mechanisms responsible for the better ability to resist herbivores are not known. 2 The present study aimed to determine the metabolic changes that are induced by early season herbivory in B. nana leaves and to study the effects of rapidly induced resistance on the growth of Epirrita autumnata larvae. 3 Defoliation of B. nana was accomplished by E. autumnata larvae and leaf samples for chemical analyses were collected when the defoliating larvae were at their third and fifth instar. At the same time, laboratory assays for the growth and consumption rates of E. autumnata larvae were conducted. 4 The wounding of leaves by E. autumna larvae induced the production of ellagitannins (ETs) in B. nana. Intriguingly, the concentrations of protein-bound amino acids were also induced by herbivory; however, an increase in proteins was not mirrored in the growth rate of larvae, which was less on the induced foliage. The decreased growth rate of larvae was apparently linked to the increased concentrations of oxidatively-active ETs and the high concentration of ETs may explain the better resistance of this parental species compared with the hybrid mountain birch with its lower levels of ETs.

Variably hungry caterpillars: predictive models and foliar chemistry suggest how to eat a rainforest

“…In fact, many outbreak geometrid species are associated with plant genera rich in ellagitannins that are primarily responsible for oxidative activity [52], e.g. Betula [53] and Quercus [54,55]. In contrast with the proanthocyanidins (syn.…”

Polyphenols in Strawberry (Fragaria × ananassa) Leaves Induced by Plant Activators

“…Polyphenolic compounds have been, and still are, important mediators in the adaptation and survival responses of plants in acute and chronic challenges. Polyphenols, such as ellagitannins, appear to play an important role in plant defense against insect pests and plant pathogens . Also, plants growing naturally in high latitudes, high temperature, and high light conditions or under low nitrogen and phosphorus availability , may contain relatively high concentrations of phenolic compounds.…”

Seasonal Variation of Plant Defense Inductor Ellagitannins in Strawberry Leaves under Field Conditions for Phytosanitary Technological Applications

“…14−17 Ellagitannins are hydrolysable tannins composed of hexahydroxydiphenoyl (HHDP) and galloyl groups esterified to glucose or other monosaccharide, which release ellagic acid upon hydrolysis. 18 In plants, ellagitannins play generally protective roles against the microbial pathogen and insect pests, 19,20 linked to their redox activity and their property to bind and precipitate proteins. 18,21 HeT exhibits antimicrobial activity through a redox reaction on microbial membranes and inhibition of the respiratory chain.…”

“…Such a compound belongs to the ellagitannin group, the class of polyphenols more abundant in Fragarina x ananassa, mainly present in the leaves. − Ellagitannins are hydrolysable tannins composed of hexahydroxydiphenoyl (HHDP) and galloyl groups esterified to glucose or other monosaccharide, which release ellagic acid upon hydrolysis . In plants, ellagitannins play generally protective roles against the microbial pathogen and insect pests, , linked to their redox activity and their property to bind and precipitate proteins. , …”