The 7B-1 mutation in tomato (Solanum lycopersicum L.) confers a blue light-specific lower sensitivity to coronatine, a toxin produced by Pseudomonas syringae pv. tomato.
The spontaneous mutant 7B-1 in tomato (Solanum lycopersicum=Lycopersicon esculentum) is a photoperiod-dependent male-sterile mutant previously reported as resistant to various abiotic stresses specifically under blue light. Since this finding improved the potential of 7B-1's use in breeding programmes, its susceptibility to stress induced by coronatine (COR), the phytotoxine produced by several Pseudomonas syringae strains, was assessed in this study. The 7B-1 mutant was found to be less sensitive than the corresponding wild type (WT) to COR treatment in a blue light-dependent manner. Treatment of WT and 7B-1 plants with COR induced a strong accumulation of salicylic acid (SA), jasmonic acid (JA), and abscisic acid (ABA) in hypocotyls. Interestingly, accumulation of ABA and SA in the 7B-1 mutant was distinctly greater than in WT, especially in blue light. Based on the cross-talk between SA- and JA-signalling pathways, expression analysis of NPR1 and COI1 genes, respectively involved in these pathways, was investigated in COR-stressed plants. The blue light-specific lower sensitivity of 7B-1 plants to COR was found to be associated with blue light-specific overexpression of the NPR1 gene. These data suggest that the SA-dependent NPR1-dependent pathway could be involved in the lower sensitivity of the 7B-1 mutant to COR. The role of anthocyanins and ABA accumulation during the response to COR is also discussed in the present study.
Bergougnoux
Véronique
V
Palacky University in Olomouc, Faculty of Science, Department of Cell Biology and Genetics, Laboratory of Molecular Physiology, Slechtitelů 11, 783 71 Olomouc, Czech Republic.
Hlavácková
Vladimíra
V
Plotzová
Renáta
R
Novák
Ondrej
O
Fellner
Martin
M
D000040:Abscisic Acid / Q000378:metabolism; D000596:Amino Acids / Q000494:pharmacology*; D000872:Anthocyanins / Q000378:metabolism; D001427:Bacterial Toxins / Q000494:pharmacology*; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D007192:Indenes / Q000494:pharmacology*; D008027:Light; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects*; D008954:Models, Biological; D009154:Mutation / Q000235:genetics*; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000187:drug effects / Q000382:microbiology / Q000528:radiation effects; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D044224:Pseudomonas syringae / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000596:Amino Acids; D000872:Anthocyanins; D001427:Bacterial Toxins; D003517:Cyclopentanes; D007192:Indenes; D054883:Oxylipins; D010940:Plant Proteins; C058487:coronatine; C011006:jasmonic acid; D000040:Abscisic Acid