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Phosphite primed defence responses and enhanced expression of defence genes in Arabidopsis thaliana infected with Phytophthora cinnamomi
Author(s) -
Eshraghi L.,
Anderson J.,
Aryamanesh N.,
Shearer B.,
McComb J.,
Hardy G. E. StJ.,
O’Brien P. A.
Publication year - 2011
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1111/j.1365-3059.2011.02471.x
Subject(s) - callose , biology , phytophthora cinnamomi , jasmonic acid , salicylic acid , arabidopsis thaliana , inoculation , zoospore , botany , methyl jasmonate , phytophthora , microbiology and biotechnology , gene , spore , horticulture , biochemistry , cell wall , mutant
This paper describes the effect of phosphite (Phi), a systemic chemical, on the induction of defence responses in Phytophthora cinnamomi ‐infected Arabidopsis thaliana accessions Ler and Col‐0. Application of Phi to non‐inoculated A . thaliana seedlings of accession Ler elevated transcription of defence genes in the salicylic acid ( PR1 and PR5 ) and jasmonic acid/ethylene ( THI2.1 and PDF1.2 ) pathways. Furthermore, a systemic increase in the expression of the PR1 gene was demonstrated in Phi‐treated seedlings using the transgenic line PR1 :: GUS in the presence/absence of the pathogen by 72 h after inoculation. The cells of Phi‐treated A. thaliana Ler leaves responded to P. cinnamomi zoospore inoculation with a rapid increase in callose deposition and hydrogen peroxide (H 2 O 2 ) production. Phi treatment resulted in the production of callose papillae 6 h earlier than in non‐Phi‐treated inoculated seedlings and enhanced the production of H 2 O 2 in the leaves of A. thaliana at the site of hyphal penetration and in cells away from the inoculation point. By 24 h after infection, clear differences in the amount of H 2 O 2 production were observed between the Phi‐treated and non‐Phi‐treated plants. These rapid host responses did not occur in non‐Phi‐treated inoculated seedlings. There was also a significant ( P < 0·001) decrease in lesion size in Phi‐treated plants. These results indicate that Phi primes the plant for a rapid and intense response to infection involving heightened activation of a range of defence responses.