Pathogen-Induced Accumulation of an Ellagitannin Elicits Plant Defense Response

MAMANI DE MARCHESE, MA. ALICIA; FILIPPONE, MA. PAULA; GRELLET BOURNONVILLE, CARLOS F.; WELIN, B; CASTAGNARO, A.P.; DÍAZ RICCI, JUAN C.

MOLECULAR PLANT-MICROBE INTERACTIONS

AMER PHYTOPATHOLOGICAL SOC

Lugar: Minnesota; Año: 2012 vol. 25 p. 1430 - 1439

0894-0282

In an incompatible interaction between Colletotrichum fragariae and strawberry plants the accumulation of phenolic compounds in plant leaves was observed. A particularly abundant penta-esterified ellagitannin that accumulated in response to pathogen attack was identified as 1-0-galloyl-2,3;4,6-bis-hexahydroxydiphenoyl-a-D-glucopyranose (HeT) by mass spectroscopy and nuclear magnetic resonance. Foliar application of purified HeT prior to inoculation with a virulent pathogen was shown to increase resistance towards C. acutatum in strawberry plants and to Xanthomonas citri subsp. citri in lemon plants. The induced resistance in strawberry was associated with a rapid oxidative burst, callose deposition, a transient increase of salicylic acid in phloem and induction of gene expression responsive to salicylic acid. Results obtained suggested that HeT could be a common plant defense response molecule capable of inducing pathogen resistance in different plant species.