Class I TCP proteins regulate organ growth and development in Arabidpsis thaliana

UBERTI MANASSERO, NG; GONZÁLEZ, DH

San Miguel de Tucumán, Tucumán, Argenitna

Congreso; XLV Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular (SAIB); 2009

Class I TCP proteins regulate organ growth and development in Arabidopsis thaliana Uberti Manassero NG, Gonzalez DH Instituto de Agrobiotecnología del Litoral (IAL-CONICET-UNL). Santa Fe E-mail: norauberti@yahoo.com.ar                          TCP-domain proteins constitute a family of plant transcription factors generally involved in the regulation of cell growth and proliferation. Arabidopsis thaliana contains 25 different TCP proteins that can be divided into two classes. In order to analyze the role of class I TCP transcription factors, we transformed Arabidopsis plants with constructs that express AtTCP11 and AtTCP15 fused to the EAR repressor domain under the control of either the 35SCaMV or their own promoters. Transformed plants over-expressing AtTCP11-EAR exhibit lobed and asymmetric leaves, short pedicels and stems, and shortened siliques with a reduced number of seeds respective to wild-ype plants. Expression of AtTCP15-EAR from the 35SCaMV promoter arrested seedling growth at early developmental stages. Supporting the idea that AtTCP15 is crucial for proper plant development, lines that express AtTCP15-EAR from its own promoter have a severe phenotypic alterations showing asymmetric upward-curled leaves, reduced stem and pedicel elongation and, in the strongest cases, downward pointing flowers with organ alterations. We also generated plants that contain promoter fusions to the gus gene to analyze the expression patterns conferred by both promoters. Taken together, the results indicate that the class I TCP proteins under study play an important role in the regulation of organ growth and development.