Regulatory networks of TCP transcription factors during Arabidopsis seedling development

VIOLA I.

Rosario

Simposio; RAFV Conference 2023, XXXIV Argentinian Meeting of Plant Physiology; 2023

Sociedad Argentina de Fisiología Vegetal

After germination, exposure to light promotes the opening and expansion of the cotyledons and the development of the photosynthetic apparatus in a process called de-etiolation. This process is crucial for seedling establishment and photoautotrophic growth. However, transition to light is a challenge for dark-germinated seedlings, since light can be harmful to the plant during the de-etiolation process. When the plant grows in dark conditions, illumination can produce photooxidative damage, which affects the accumulation of chlorophyll, photosynthesis and, eventually, the growth or survival of the plant. To avoid this, a number of key regulatory factors are required for the control of chlorophyll biosynthesis during this transition. TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTORS (TCP) transcription factors constitute a plant-specific protein family that participates in the regulation of numerous processes of growth and development during the life cycle of plants, acting through the recruitment of other factors and the modulation of different hormonal pathways. In our laboratory, we found that different TCP proteins participate in processes associated with de-etiolation, like cotyledon opening and expansion, as well as the induction of genes encoding components of the photosynthetic apparatus, physically interacting with the transcription factor GLK1 and integrating into the transcriptional network associated with this transcription factor. TCP proteins also affect the accumulation of chlorophyll precursors in etiolated seedlings supporting a role of these proteins in the protection from photooxidative damage after light exposure. The molecular mechanisms related to the action of TCP transcription factors in these processes will be discussed