CHRONOBIOLOGICAL STUDY OF PHYSIOLOGICAL VARIABLES AND ANTIOXIDANT METABOLISM IN Glycine max L.

GATICA AGUILAR CV; PEREZ CHACA V; ANZULOVICH AC; PARDO D; GOLINI RS

MODALIDAD VIRTUAL

Congreso; XXXIX REUNION CIENTIFICA DE LA SOCIEDAD DE BIOLOGIA DE CUYO; 2021

The Earth rotation exposes most of the planet's species to the environmental daily oscillations. These external oscillations synchronize theinternal biological clocks that generate biological rhythms in the organisms, to anticipate the environmental changes. Among these rhythms,the circadian, 24h-rhythms, are the most studied. In plants, the initiation of photosynthesis after sunrise (periodic process) triggers theaccumulation of metabolites, including the production of reactive oxygen species (ROS). ROS represent a constant threat to plants, as theyreact with different cellular components generating oxidative stress. However, plants have developed mechanisms to maintain redoxhomeostasis. The oscillations in ROS production, removal and signaling would involve the plant biological clock. The functions of clockoscillators in agriculturally important species, such as soybean (Glycine max L.), are increasingly recognized. Soybean is one of the mostimportant and cultivated legumes in the world and constitutes the main export item of Argentina, one of the main producing countriesworldwide. Therefore, the objective of this work was to study the influence of the biological clock on the physiology and antioxidantmetabolism of Glycine max L. throughout a 24-hour period. For this purpose, soybean cultures were grown in hydroponics for 7 days understandard environmental conditions, with a 14h-light:10h-dark photoperiod. Biochemical (antioxidant enzyme activity, lipid peroxidationand H2O2 levels), physiological (photosynthetic pigment concentration) and molecular (primer design, identification of transcription factorbinding sites) parameters, were determined in soybean leaves. Interestingly, we found that Catalase activity (p