tailieunhanh - báo cáo khoa học: "Role of TRIPTYCHON in trichome patterning in Arabidopsis"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Role of TRIPTYCHON in trichome patterning in Arabidopsis | Pesch and Hulskamp BMC Plant Biology 2011 11 130 http 1471 -2229 11 130 BMC Plant Biology RESEARCH ARTICLE Open Access Role of TRIPTYCHON in trichome patterning in Arabidopsis Martina Pesch and Martin Hulskamp Abstract Background Trichome patterning in Arabidopsis thaliana is governed by three types of activators R2R3MYB bHLH and WD40 proteins and six R3MYB inhibitors. Among the inhibitors TRIPTYCHON TRY seems to fulfill a special function. Its corresponding mutants produce trichome clusters whereas all other inhibitors are involved in trichome density regulation. Results To better understand the role of TRY in trichome patterning we analyzed its transcriptional regulation. A promoter analysis identified the relevant regulatory region for trichome patterning. This essential region contains a fragment required for a double negative feedback loop such that it mediates the repression of TRY CPC autorepression. By transforming single cells of pTRY GUS lines with p35S GL1 p35S GL3 and p35S TTG1 in the presence or absence of p35S TRY or p35S CPC we demonstrate that TRY and CPC can suppress the TRY expression without the transcriptional down regulation of the activators. We further show by promoter CDS swapping experiments for the R3MYB inhibitors TRY and CPC that the TRY protein has specific properties relevant in the context of both cluster formation and trichome density. Conclusions Our identification of a TRY promoter fragment mediating a double negative feedback loop reveals new insight in the regulatory network of the trichome patterning machinery. In addition we show that the autorepression by TRY can occur without a transcriptional down regulation of the activators suggesting that the differential complex formation model has a biological significance. Finally we show that the unique role of TRY among the inhibitors is a property of the TRY protein. Background Trichome patterning in Arabidopsis thaliana has become a well-studied model system .