Circadian Clock-Regulated Phosphate Transporter PHT4;1 Plays an Important Role in Arabidopsis Defense
Circadian Clock-Regulated Phosphate Transporter PHT4;1 Plays an Important Role in Arabidopsis Defense作者机构:Department of Biological Sciences University of Maryland Baltimore County 1000 Hilltop CircLe Baltimore MD 21250 USA
出 版 物:《Molecular Plant》 (分子植物(英文版))
年 卷 期:2011年第4卷第3期
页 面:516-526页
核心收录:
学科分类:08[工学] 09[农学] 0901[农学-作物学] 0836[工学-生物工程] 090102[农学-作物遗传育种]
基 金:国家自然科学基金
主 题:Biological clock disease resistance signal transduction Pseudomonas syringae phosphate transporter salicylic acid.
摘 要:The Arabidopsis accelerated cell death 6-1 (acd6-1) mutant shows constitutive defense, cell death, and ex- treme 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. Treat- ment 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 -in- dependent 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 reg- ulated 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.