Pathogen-responsive expression of a putative ATP-binding cassette transporter gene conferring resistance to the diterpenoid sclareol is regulated by multiple defense signaling pathways in Arabidopsis.
The ATP-binding cassette (ABC) transporters are encoded by large gene families in plants. Although these proteins are potentially involved in a number of diverse plant processes, currently, very little is known about their actual functions. In this paper, through a cDNA microarray screening of anonymous cDNA clones from a subtractive library, we identified an Arabidopsis gene (AtPDR12) putatively encoding a member of the pleiotropic drug resistance (PDR) subfamily of ABC transporters. AtPDR12 displayed distinct induction profiles after inoculation of plants with compatible and incompatible fungal pathogens and treatments with salicylic acid, ethylene, or methyl jasmonate. Analysis of AtPDR12 expression in a number of Arabidopsis defense signaling mutants further revealed that salicylic acid accumulation, NPR1 function, and sensitivity to jasmonates and ethylene were all required for pathogen-responsive expression of AtPDR12. Germination assays using seeds from an AtPDR12 insertion line in the presence of sclareol resulted in lower germination rates and much stronger inhibition of root elongation in the AtPDR12 insertion line than in wild-type plants. These results suggest that AtPDR12 may be functionally related to the previously identified ABC transporters SpTUR2 and NpABC1, which transport sclareol. Our data also point to a potential role for terpenoids in the Arabidopsis defensive armory.
Campbell
Emma J
EJ
Cooperative Research Centre for Tropical Plant Protection, The University of Queensland, St. Lucia, Queensland 4072, Australia.
Schenk
Peer M
PM
Kazan
Kemal
K
Penninckx
Iris A M A
IA
Anderson
Jonathan P
JP
Maclean
Don J
DJ
Cammue
Bruno P A
BP
Ebert
Paul R
PR
Manners
John M
JM
D018528:ATP-Binding Cassette Transporters / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D000085:Acetates / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004224:Diterpenes / Q000494:pharmacology*; D005030:Ethylenes / Q000494:pharmacology; D005658:Fungi / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000187:drug effects / Q000235:genetics; D007113:Immunity, Innate / Q000235:genetics; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D020156:Salicylic Acid / Q000494:pharmacology; D012639:Seeds / Q000187:drug effects / Q000235:genetics; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000235:genetics* / Q000502:physiology
D018528:ATP-Binding Cassette Transporters; D000085:Acetates; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D018076:DNA, Complementary; D004224:Diterpenes; C455514:EDS5 protein, Arabidopsis; D005030:Ethylenes; D026901:Membrane Transport Proteins; C105496:NPR1 protein, Arabidopsis; D054883:Oxylipins; C482841:PDR12 protein, Arabidopsis; C072239:methyl jasmonate; C036216:ethylene; C070760:sclareol; D020156:Salicylic Acid