Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Localization of DIR1 at the tissue, cellular and subcellular levels during Systemic Acquired Resistance in Arabidopsis using DIR1:GUS and DIR1:EGFP reporters | Champigny et al. BMC Plant Biology 2011 11 125 http 1471-2229 11 125 BMC Plant Biology RESEARCH ARTICLE Open Access Localization of DIR1 at the tissue cellular and subcellular levels during Systemic Acquired Resistance in Arabidopsis using DIR1 GUS and DIR1 EGFP reporters h I V r I n I Z1 k k 1 4 I_I Z I b H Z r c hz M r1 4 A r I f h ỉ fs n m m z l 1 ì z Z I_I n iv z r 1 h z Z I f z l Mm I m 2 D fs mt Z z I I I I rn z k z3 5 Marc J Cnampigny reamer Shearer asit MOndmmdO Karen names Melody Neumann Roger irnimony Sheng Yang He3 Pierre Fobert4 Nancy Dengler2 and Robin K Cameron1 Abstract Background Systemic Acquired Resistance SAR is an induced resistance response to pathogens characterized by the translocation oT a long-distance signal from induced leaves to distant tissues to prime them Tor increased resistance to future infection. DEFECTIVE in INDUCED RESISTANCE 1 DIR1 has been hypothesized to chaperone a small signaling molecule to distant tissues during SAR in Arabidopsis. Results DIR1 promoter DIR1-GUS dir1-1 lines were constructed to examine DIR1 expression. DIR1 is expressed in seedlings flowers and ubiquitously in untreated or mock-inoculated mature leaf cells including phloem sieve elements and companion cells. Inoculation of leaves with SAR-inducing avirulent or virulent Pseudomonas syringae pv tomato Pst resulted in Type III Secretion System-dependent suppression of DIR1 expression in leaf cells. Transient expression of fluorescent fusion proteins in tobacco and intercellular washing fluid experiments indicated that DIR1 s ER signal sequence targets it for secretion to the cell wall. However DIR1 expressed without a signal sequence rescued the dir1-1 SAR defect suggesting that a cytosolic pool of DIR1 is important for the SAR response. Conclusions Although expression of DIR1 decreases during SAR induction the protein localizes to all living cell types of the vasculature including companion cells and sieve elements and therefore DIR1 .
