Role of AtTCP15 in the regulation of carpel development and cytokinin responses in Arabidopsis thaliana.

UBERTI MANASSERO, NG; GONZÁLEZ, DH

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2012

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

TCP-domain proteins constitute a family of transcription factors specific of plants. They can be divided into two classes, I and II. The precise function and mechanism of action of many class I TCP proteins is not well understood. In order to elucidate this, we transformed Arabidopsis plants with the coding region of AtTCP15 fused to the EAR repressor domain, under the control of its own promoter (p15::TCP15-EAR). We obtained plants with altered gynoecia that showed an overgowth of the replum, forming narrow structures ended in stigmatic papillae. Application of cytokinin to p15::TCP15-EAR plants generated an overproduction of stigmatic papillae along the medial zone and a pronounced arrest in carpel elongation. Production of similar structures was observed after treatment of a knockout mutant in AtTCP15. Interestingly, plants ectopically expressing AtTCP15 showed defects in carpel fusion under normal conditions and abnormal proliferation of carpel-like structures in the gynoecium when treated with cytokinin.According to this, several cytokinin response regulators (ARRs) showed changes in expression in plants with altered AtTCP15 function. Taken together, these results suggest an important role of AtTCP15 in regulating cell proliferation and diferentiation in the gynoecium through the modulation of cytokinin response pathways.