PHYSIOLOGICAL RESPONSE OF SANTOLINA (Santolina chamaecyparissus) EXPOSED TO LEAD

CORTEZ, FACUNDO; ORDEN, AGUSTINA; CANTARELLI, MIGUEL ANGEL; MOLDES, CARLOS ALBERTO

Ciudad Autónoma de Buenos Aires

Jornada; XXIV ANNUAL MEETING OF THE ARGENTINEAN SOCIETY OF BIOLOGY (SAB); 2022

Sociedad Argentina de Biología

The objective of this work is to determine the physiological response of the santolina plants (Santolina chamaecyparissus) against lead (Pb) stress. The experiment was set up with seedlings in pots of 1 kg with a substrate of sand:vermiculite (3:1) in a greenhouse. 30 days later, 1 g of Nitrofull fertilizer with macro and micronutrients was applied to each of the plants. After 32 days, a PbCl2 solution was used, where the final concentration of Pb in the substrate was 0, 250, 500, 1000, and 2000 ppm. After 25 weeks, the volume of each plant was estimated using image analysis software as a growth parameter. In addition, samples of each treatment were collected, and lipid peroxidation was determined as a stress indicator. Enzymatic activity of catalase, ascorbate peroxidase, and guaicol peroxidase was also measured. The data was analyzed through univariate and multivariate statistics (P < 0.05), which indicated that the concentrations up to 1000 ppm of the metal did not present a significant difference with respect to the control treatment in the growth parameter and in the enzymatic measurements. However, in the samples that contained 2000 ppm, it was possible to observe that there were significant differences with respect to the others, where the value of the growth parameter decreased, and the values of the enzymatic measurements increased. In the treatments from 250 to 2000 ppm of Pb, the concentration of the metal in the aerial part was lower than in the substrate, and the measured value never exceeded the value of 1000 ppm taken as a reference for the plant to be a hyperaccumulator. Significant differences in the growth parameters and in the enzymatic activity with respect to the control treatment were found from 2000 ppm. Therefore, this specie is not considered a bioaccumulator of Pb, although it can tolerate its presence in large amounts and can be used for phytoremediation.