title: Elongator Plays a Positive Role in Exogenous NAD-Induced Defense Responses in Arabidopsis.
abstract: Extracellular NAD is emerging as an important signal molecule in animal cells, but its role in plants has not been well-established. Although it has been shown that exogenous NAD(+) activates defense responses in Arabidopsis, components in the exogenous NAD(+)-activated defense pathway remain to be fully discovered. In a genetic screen for mutants insensitive to exogenous NAD(+) (ien), we isolated a mutant named ien2. Map-based cloning revealed that IEN2 encodes ELONGATA3 (ELO3)/AtELP3, a subunit of the Arabidopsis Elongator complex, which functions in multiple biological processes, including histone modification, DNA (de)methylation, and transfer RNA modification. Mutations in the ELO3/AtELP3 gene compromise exogenous NAD(+)-induced expression of pathogenesis-related (PR) genes and resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola ES4326, and transgenic expression of the coding region of ELO3/AtELP3 in elo3/Atelp3 restores NAD(+) responsiveness to the mutant plants, demonstrating that ELO3/AtELP3 is required for exogenous NAD(+)-induced defense responses. Furthermore, mutations in genes encoding the other five Arabidopsis Elongator subunits (ELO2/AtELP1, AtELP2, ELO1/AtELP4, AtELP5, and AtELP6) also compromise exogenous NAD(+)-induced PR gene expression and resistance to P. syringae pv. maculicola ES4326. These results indicate that the Elongator complex functions as a whole in exogenous NAD(+)-activated defense signaling in Arabidopsis.
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A.
authors.forename: Chuanfu
authors.initials: C
authors.lastname: An
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A.
authors.forename: Yezhang
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A.
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A.
authors.forename: Chenggang
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, P.O. Box 110700, Gainesville, FL 32611, U.S.A.
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Mou
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant / Q000187:drug effects* / Q000502:physiology; D005810:Multigene Family; D009154:Mutation; D009243:NAD / Q000494:pharmacology*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D021122:Protein Subunits; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D021122:Protein Subunits; D009243:NAD; D020156:Salicylic Acid