MONITORING OXIDATIVE STRESS PARAMETERS AS CHLOROPHYLL LEVEL IN CADMIUN TREATED Glycine max L. PLANTS BY MOLECULAR FLUORESCENCE

FELICI, EMILIANO; CHIEN CHUN WANG; ZIRULNIK, FANNY; GOMEZ, MARÍA ROXANA; FERNANDEZ, LILIANA

Congreso; XXXII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2014

Heavy metals induce different types of stress in plants. The monitoring of chlorophyll levels is a good indicator of an imbalance in the redox homeostasis and therefore of oxidative stress. The aim of this work was to determine the increase of chlorophyll level that reveal the oxidative stress caused for Cd exposure by using molecular fluorescence. Soybean seeds were germinated and developed under controlled conditions until were used. On the 4th day of germination were placed in hydroponic conditions with Hoagland nutrient solution. On the 10th day, were exposed to Cd (40 µM) during 4, 6, 24, 72 h and 6 days. To obtain extracts, 250 mg of leaves were homogenized under ice-cold conditions in ethanol absolute. Homogenates were centrifuged for 10 min and the supernatants were analyzed. A Shimadzu RF-5301PC spectrofluorimeter equipped with a Xenon discharge lamp and quartz cells was used for molecular fluorescence measurements. Under optimal conditions, calibration curve for chorophyll was performed according to general procedure. Detection was performed at em=435 nm using ex=660 nm. Chlorophyll level determined by fluorescence showed a reduction in the chlorophyll level after 24 h, demonstrating oxidative damage in the plant. This parameter is related with a significant decrease in Mg uptake at leaf level indicating chloroplast damage. In this model, Cd exposure alters the normal physiological status of soybean plants.