Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Identification of potential target genes for the tomato fruit-ripening regulator RIN by chromatin immunoprecipitation | Fujisawa et al. BMC Plant Biology 2011 11 26 http 1471-2229 11 26 BMC Plant Biology RESEARCH ARTICLE Open Access Identification of potential target genes for the tomato fruit-ripening regulator RIN by chromatin immunoprecipitation Masaki Fujisawa Toshitsugu Nakano Yasuhiro Ito Abstract Background During ripening climacteric fruits increase their ethylene level and subsequently undergo various physiological changes such as softening pigmentation and development of aroma and flavor. These changes occur simultaneously and are caused by the highly synchronized expression of numerous genes at the onset of ripening. In tomatoes the MADS-box transcription factor RIN has been regarded as a key regulator responsible for the onset of ripening by acting upstream of both ethylene- and non-ethylene-mediated controls. However except for LeACS2 direct targets of RIN have not been clarified and little is known about the transcriptional cascade for ripening. Results Using immunoprecipitated IPed DNA fragments recovered by chromatin immunoprecipitation ChIP with anti-RIN antibody from ripening tomato fruit we analyzed potential binding sites for RIN CArG-box sites in the promoters of representative ripening-induced genes by quantitative PCR. Results revealed nearly a 5- to 20-fold enrichment of CArG boxes in the promoters of LeACS2 LeACS4 PG TBG4 LeEXPl and LeMAN4 and of RIN itself indicating direct interaction of RIN with their promoters in vivo. Moreover sequence analysis and genome mapping of 51 cloned IPed DNAs revealed potential RIN binding sites. Quantitative PCR revealed that four of the potential binding sites were enriched 4- to 17-fold in the IPed DNA pools compared with the controls indicating direct interaction of RIN with these sites in vivo. Near one of the four CArG boxes we found a gene encoding a protein similar to thioredoxin y1. An increase in the transcript level of this gene was observed with ripening in normal fruit but not in the rin .
