DISECTION OF THE FUNCTIONS OF EACH PHYTOCHROME

CHRISTIAN DAMIAN LORENZO; GUADALUPE RODRIGUEZ FERRANTE; MAXIMILIANO SANCHEZ LAMAS; CERDAN, PABLO DIEGO

Rosario

Simposio; Simposio Genómica Funcional de Plantas; 2017

IBR-CEFOBI-UNR-CONICET

To sense the changes in environmental conditions, plants had to develop different mechanisms that allow them to sense and integrate key information such as temperature and light. Arabidopsis has 13 photoreceptors capable of perceiving light, from the UV region of the spectrum to the far-red light region. Phytochromes are a small family of photoreceptors (phyA-phyE in Arabdopsis), which particularly perceive red and far-red light, whose ratio changes in shaded environments.Although the different phytochromes have overlapping roles, they have partially diverged. In addition, they have synergistic and antagonistic roles,, which allowed the emergence of new properties of the phytochrome system. Taking into account the dimeric nature of phytochromes, some of the interactions among phytochromes could result from the formaton of heterodimers. Hence, we decided to study the pair-wise interactions at the protein level and also using genetic tools, such as genetic backgrounds bearing only one or two phytochromes at a time,Our results revealed some of the emerging properties. Although phyA and phyB had the most prominent roles in the promotion of germination, phyC, phyD and phyE finetuned the response. In one hand, they acted synergistically to promote phyA and phyB responses but afterwards, they buffered this promotion by reducing the sensitivity to Gibberellins. phyC had a unique role in acting with phyB to induce the flowering response to long days, whereas phyA buffered the flowering response against temperature changes by antagonizing the role of phyE as a flowering represor at lower temperatures