Premium
Hypersensitive lignification response as the mechanism of non‐host resistance of wheat against oat crown rust
Author(s) -
Moerschbacher Bruno M.,
Noll Ulrike,
Ocampo Carlos A.,
Flott Berenike E.,
Gotthardt Uwe,
Wüslefeld Andreas,
Reisener HansJoachim
Publication year - 1990
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1990.tb05249.x
Subject(s) - haustorium , stem rust , biology , phenylalanine ammonia lyase , rust (programming language) , peroxidase , plant disease resistance , wheat leaf rust , hypersensitive response , botany , septoria , microbiology and biotechnology , host (biology) , biochemistry , virulence , enzyme , cultivar , gene , ecology , programming language , computer science
Seven‐day‐old seedlings of the near‐isogenic wheat ( Triticum aestivum L.) lines Prelude and Prelude‐Sr5, susceptible and resistant to wheat stem rust, respectively, were inoculated with uredospores of the oat crown rust fungus Puccinia coronata Cda. f. sp. avenae Fraser & Led. Fluorescence microscopy revealed that the majority of colonies developed intercellular infection structures including haustorial mother cells and haustoria after penetration of wheat mesophyll cells. All penetrated cells became necrotic, and exhibited bright yellow autofluorescence. This autofluorescence was not extractable with alkali, and fluorescent cells stained positively with phloroglucinol/HCI, suggesting that hypersensitive cell death was correlated with cellular lignification. Accordingly, the lignin biosynthetic enzymes phenylalanine ammonia‐lyase (EC4.3.1.5). 4‐coumarate:CoA ligase (EC6.2.1.12), cinnamyl‐alcohol dehydrogenase (EC1.1.1.149), and peroxidases (EC1.11.1.7) increased in activity during the expression of resistance. The induced pattern of peroxidase iso/ymes closely resembled that observed for highly incompatible wheat/wheat stem rust interactions. Furthermore, an elieitor was extracted from oat crown rust germlings. which induces lignification when injected into the intercellular space of wheat leaves. This elieitor appears to be functionally similar to that isolated from wheat stem rust germlings. The results suggest that the non‐host resistance of wheat to the xenopara‐site oat crown rust closely resembles the race/cullivar‐speeific resistant mechanism of highly resistant wheat varieties to wheat stem rust.