El factor de transcripción AtTCP15 regula el desarrollo del gineceo a través de la homeostasis de auxinas y la respuesta a citoquininas

LUCERO, LE; UBERTI MANASSERO, NG; GONZÁLEZ, DH

Rosario, Santa Fe

Congreso; L Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2014

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

The TCP transcription factor family belongs exclusively to plants and is involved mainly in plant development. We studied the function of a poorly known member of A. thaliana, TCP15. To this end, we transformed plants with the coding region of TCP under the control of the 35SCaMV promoter; these plants present defects in the apical portion of gynoecia, where lack of fusion between the two carpels was observed. In contrast, the expression of TCP15 fused to the repressor domain EAR originates the development of outgrowths topped with stigmatic papillae from the replum. In Arabidopsis, the correct development of the gynoecium is regulated by an auxin gradient, with a maximum in the apical portion. Two auxin biosynthesis genes, YUC1 and YUC4, presented lower expression levels in 35S:AtTCP15 plants, and higher in TCP15-EAR. In addition, these plants showed lower expression of the auxin reporter DR5:GUS in gynoecia. The effects of overexpressing TCP15 or its repressor form on gynoecium development are enhanced after cytokinin treatment. In addition, treatment of a loss-of-function tcp14 tcp15 double mutant with cytokinin originates an increased development of outgrowths from the replum and the induction of the auxin biosynthesis gene YUC4. These results suggest that AtTCP15 participates in the proper development of the gynoecium by influencing the cross-talk between auxin and cytokinin.