title: Circadian clock-regulated phosphate transporter PHT4;1 plays an important role in Arabidopsis defense.
abstract: The Arabidopsis accelerated cell death 6-1 (acd6-1) mutant shows constitutive defense, cell death, and extreme dwarf phenotypes. In a screen for acd6-1 suppressors, we identified a mutant that was disrupted by a T-DNA in the PHOSPHATE TRANSPORTER 4;1 (PHT4;1) gene. The suppressor mutant pht4;1-1 is dominant, expresses truncated PHT4;1 transcripts, and is more susceptible to virulent Pseudomonas syringae strains but not to several avirulent strains. Treatment with a salicylic acid (SA) agonist induced a similar level of resistance in Col-0 and pht4;1-1, suggesting that PHT4;1 acts upstream of the SA pathway. Genetic analysis further indicates that PHT4;1 contributes to SID2-dependent and -independent pathways. Transgenic expression of the DNA fragment containing the PHT4;1-1 region or the full-length PHT4;1 gene in wild-type conferred enhanced susceptibility to Pseudomonas infection. Interestingly, expression of PHT4;1 is regulated by the circadian clock. Together, these data suggest that the phosphate transporter PHT4;1 is critical for basal defense and also implicate a potential role of the circadian clock in regulating innate immunity of Arabidopsis.
authors: Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
authors: Guo-Ying
authors: GY
authors: Wang
authors: Jiang-Li
authors: JL
authors: Shi
authors: Gina
authors: G
authors: Ng
authors: Stephanie L
authors: SL
authors: Battle
authors: Chong
authors: C
authors: Zhang
authors: Hua
authors: H
authors: Lu
mesh_terms: D017487:Ankyrins / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D057906:Circadian Clocks / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D005799:Genes, Dominant / Q000235:genetics; D008027:Light; D010641:Phenotype; D028061:Phosphate Transport Proteins / Q000235:genetics / Q000378:metabolism*; D011549:Pseudomonas / Q000187:drug effects / Q000472:pathogenicity / Q000528:radiation effects; D020156:Salicylic Acid / Q000494:pharmacology; D013489:Suppression, Genetic / Q000187:drug effects / Q000528:radiation effects; D014774:Virulence / Q000187:drug effects / Q000528:radiation effects
chemical_list: D017487:Ankyrins; D029681:Arabidopsis Proteins; D028061:Phosphate Transport Proteins; D020156:Salicylic Acid; C480953:ACD6 protein, Arabidopsis; C529796:ANTR-1 protein, Arabidopsis