Physiological and molecular mechanisms underlying the integration of light and temperature cues in seeds of Arabidopsis thaliana.

TOGNACCA RS; BOTTO JF; ESTRAVIS-BARCALÁ M; ARANA MV; SANCHEZ RA

CORRIENTES

Congreso; XXXI Reunión Argentina de Fisiología Vegetal; 2016

Seeds sense a number of cues that provide information about the environment which are integrated in the regulation of developmental processes such as dormancy and germination. In several species, light and temperature are signals of outmost relevance for the modulation of dormancy level. Despite of its ecological and economic importance, the genetic mechanisms involved in the light-mediated control of dormancy in combination with temperature are scarcely known. Here we show that daily temperature cycles promote red-mediated germination, through the phytochrome B, in Arabidopsis seeds. Using a set of circadian clock loss of function mutants, we show that the synergism between light and temperature cycles is strongly reduced in toc1 and prr7 mutant seeds, but it is present other clock mutants, indicating that this response is regulated by specific clock components, belonging to the evening loop. Experiments in course in our lab indicate that daily temperature cycles reduce the expression of DOG1, and that the effect of daily temperature cycles is negatively regulated by DOG1. The synergism between light and temperature reported here may provide the individuals with the ability to adjust patterns ofgermination to environments of ecological relevance.