TCP14 AND TCP15 PARTICIPATE IN TEMPERATURE-DEPENDENT DEVELOPMENTAL RESPONSES IN ARABIDOPSIS THALIANA

LUCIA FERRERO; IVANA L. VIOLA; DANIEL H. GONZALEZ

Cordoba

Congreso; LII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2016

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

TCP proteins integrate a family of transcription factors that belong exclusively to plants. These proteins are mainly involved in the regulation of developmental processes and hormone responses and they can be grouped into two major classes, I and II. In this work, we studied the role of class I TCP proteins in hypocotyl development, focusing in TCP15 from Arabidopsis thaliana.We analyzed the growth of the hypocotyl of mutant plants in AtTCP14 and AtTCP15, tcp14-tcp15, in different conditions as darkness and high temperature. We observed that these plants were unable to modulate the elongation of the hypocotyl in darkness and this was not reversed with a treatment with gibberellins or auxins. This defect in hypocotyl elongation was also observed when these plants were grown at 29°C, a condition in which the concentration of endogenous auxins it is increased. We also analyzed in these plants the transcript levels of genes involved in the biosynthesis, signalling or response to auxins and gibberellins. In addition, we observed that the expression of AtTCP15 is altered in the PIF4 mutant pif4-2 whose hypocotyls are also unable to respond to heat. Reciprocally PIF4 transcript levels are altered in the mutant tcp15-3. Our results have enabled us to raise several hypotheses about what would be the molecular mechanism by which these proteins regulate hypocotyl elongation in these conditions.