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Silencing of OPR3 in tomato reveals the role of OPDA in callose deposition during the activation of defense responses against Botrytis cinerea
Author(s) -
Scalschi Loredana,
Sanmartín Maite,
Camañes Gemma,
Troncho Pilar,
SánchezSerrano José J.,
GarcíaAgustín Pilar,
Vicedo Begonya
Publication year - 2015
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 - 10.1111/tpj.12728
Subject(s) - callose , jasmonic acid , gene silencing , solanum , botrytis cinerea , genetically modified crops , biology , pathogen , plant defense against herbivory , microbiology and biotechnology , salicylic acid , transgene , biochemistry , botany , gene
Summary C is ‐(+)‐12‐oxo‐phytodienoic acid ( OPDA ) is likely to play signaling roles in plant defense that do not depend on its further conversion to the phytohormone jasmonic acid. To elucidate the role of OPDA in S olanum lycopersicum (tomato) plant defense, we have silenced the 12‐oxophytodienoate reductase 3 ( OPR 3 ) gene. Two independent transgenic tomato lines ( Si OPR 3‐1 and Si OPR 3‐2 ) showed significantly reduced OPR 3 expression upon infection with the necrotrophic pathogen B otrytis cinerea . Moreover, Si OPR 3 plants are more susceptible to this pathogen, and this susceptibility is accompanied by a significant decrease in OPDA levels and by the production of JA ‐Ile being almost abolished. OPR 3 silencing also leads to a major reduction in the expression of other genes of the jasmonic acid ( JA ) synthesis and signaling pathways after infection. These results confirm that in tomato plants, as in A rabidopsis, OPR 3 determines OPDA availability for JA biosynthesis. In addition, we show that an intact JA biosynthetic pathway is required for proper callose deposition, as its pathogen‐induced accumulation is reduced in Si OPR 3 plants. Interestingly, OPDA , but not JA , treatment restored basal resistance to B . cinerea and induced callose deposition in Si OPR 3‐1 and Si OPR 3‐2 transgenic plants. These results provide clear evidence that OPDA by itself plays a major role in the basal defense of tomato plants against this necrotrophic pathogen.