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Systemic induction of salicylic acid‐related plant defences in potato in response to Rhizoctonia solani AG 3 PT
Author(s) -
Genzel F.,
Franken P.,
Witzel K.,
Grosch R.
Publication year - 2018
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/ppa.12746
Subject(s) - rhizoctonia solani , biology , pathogen , jasmonic acid , inoculation , salicylic acid , colonization , alternaria solani , microbiology and biotechnology , plant defense against herbivory , botany , horticulture , gene , blight , genetics
The necrotrophic pathogen Rhizoctonia solani affects potato ( Solanum tuberosum ) quality worldwide. The pathogen infects below‐ground parts of potato during growth. Very little information is available on the extent of colonization of roots by R. solani AG 3 PT and especially on the defence responses in roots following sprout inoculation with the pathogen. It was hypothesized that infection of the primary sprout results in colonization of the roots by the pathogen, and that R. solani as a necrotroph induces jasmonic acid/ethylene ( JA / ET )‐related defence responses in sprouts and in the root. Seven well‐described genes of general defence responses against fungal pathogens were selected for this study. The expression of these genes was investigated at the transcript level and, for four genes, at the protein level in roots and sprouts at 3, 6 and 13 days post‐inoculation (dpi). In addition, the density of colonization of roots with R. solani AG 3 PT was analysed. Roots were quickly colonized by R. solani following sprout inoculation; however, the rapidly growing root was not further extensively colonized by the pathogen. Furthermore, an increase in transcript and protein levels of the defence‐related genes associated with JA / ET ‐ ( PR ‐2 ) and SA ‐dependent pathways ( PR ‐1 , PR ‐3 and PR ‐10 ) was detected in roots and sprouts at 3 and 6 dpi. However, the susceptible potato cultivar was not able to maintain the elevated transcript level of defence‐related genes in roots and sprouts. The results underline that not only the JA / ET ‐ but also the SA ‐dependent pathway plays a role during interaction of the necrotrophic pathogen R. solani AG 3 PT with its host potato.