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Elicitor induced defence responses in medicago sativa
Author(s) -
Tang M.,
Smith C. J.
Publication year - 2001
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.2001.00062.x
Subject(s) - elicitor , medicago sativa , scopoletin , biochemistry , phenylalanine ammonia lyase , cytosol , biology , peroxidase , chemistry , botany , enzyme , medicine , alternative medicine , pathology
Summary• The effects are reported here of an elicitor prepared from liquid cultures of an isolate of Verticillium albo‐atrum , which is nonpathogenic to Medicago sativa , on accumulation of H 2 O 2 , medicarpin, deposition of phenolic polymer and phenylalanine ammonia‐lyase (PAL) activity in cultured cells of Medicago sativa L. cv. Kabul (lucerne). • PAL activity and phytoalexins were assayed spectrophotometically and by HPLC, respectively. The scopoletin fluorescence‐quenching and thioglycolic acid methods were used to measure H 2 O 2 and phenolic polymer deposition, respectively. • Studies with inhibitors suggested that an NAD(P)H oxidase and a peroxidase were involved in the elicitor stimulated accumulation of H 2 O 2 and that an increase in cytosolic Ca 2+ , but not H 2 O 2 , was part of a signalling pathway leading to the induction of defence responses. • Both the influx of Ca 2+ and release of Ca 2+ from intracellular stores forms part of the signalling pathway leading from perception of elicitor to induction of defence responses. Although H 2 O 2 is not part of the pathway, evidence is presented that O 2 − is part of the signal transduction chain.