Functional studies of AtTCP8, a transcription factor involved in plant development and architecture

ALEJANDRA CAMOIRANO; DANIEL GONZALEZ; IVANA VIOLA

Foz do Iguaçu

Congreso; 11th Congress of International Plant Molecular Biology (IPMB); 2015

Transcription factors of the TCP family can be found only in plants and are involved in growth and development. Initially, they were thought to play a role in cell growth and proliferation but now it is known that they are also involved in the regulation of hormone homeostasis, the circadian cycle, plant immunity, germination, and senescence, thus regulating plant growth and development in response to both internal and external stimuli.TCPs have a conserved domain of 59 aa that is involved in DNA binding and dimerization. Based on distinctive features present both within and outside this domain, TCPs are divided into two classes: I and II. Among both subfamilies, proteins of class I are much less studied. Our interest has specifically fallen on a member of class I of Arabidopsis thaliana: AtTCP8, since little is known about its function and the molecular mechanisms through which it operates. We found that plants that express TCP8 from the 35SCaMV promoter flower earlier than wild-type and have changes in the number and shape of leaves and in plant architecture. In agreement with these results, FT and SOC1, two genes involved in the promotion of flowering, showed increased expression in these plants. Plants transformed with a promoter:GUS fusion showed reporter activity mainly in meristems and vascular tissues, including expression along the entire plant life cycle, such as roots, rosette and cauline leaves, and flowers. Taken together, our results suggest that this transcription factor regulates several aspects of plant development and architecture in Arabidopsis.