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Identification of an essential component of the elicitation active site of the EIX protein elicitor
Author(s) -
Rotblat Barak,
EnshellSeijffers David,
Gershoni Jonathan M.,
Schuster Silvia,
Avni Adi
Publication year - 2002
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2002.01490.x
Subject(s) - elicitor , pentapeptide repeat , biology , biochemistry , polyclonal antibodies , plant defense against herbivory , computational biology , peptide , microbiology and biotechnology , enzyme , genetics , gene , antibody
Summary Defense mechanisms of plants against pathogens often entail cell wall strengthening, ethylene biosynthesis, expression of pathogen‐related proteins and hypersensitive responses (HR). Pathogen‐derived elicitors trigger these defense responses. The Elicitor Ethylene‐inducing Xylanase (EIX) elicits HR and other plant defense responses in some tobacco and tomato cultivars independently of its xylan degradation activity. The elicitation epitope on the EIX protein responsible for inducing the HR response has been elucidated. Through the generation of EIX‐specific polyclonal antibodies and screening of combinatorial phage display peptide libraries an essential sequence of the EIX elicitation activity has been identified. This sequence consists of the pentapeptide TKLGE mapped to an exposed β‐strand of the EIX protein. Substitution of the pentapeptide TKLGE to VKGT inhibited the elicitation activity but not the β‐1‐4‐endoxylanase activity of the EIX protein further demonstrating that elicitation and enzyme activity are independent properties. Elucidation of a peptide sequence that is essential for elicitation of HR creates the opportunity to understand the control and signaling of plant defense.