PRIMING IN WHEAT (Triticum aestivum L) SEEDS WITH SPERMINE AS A TOLERANCE STRATEGY TO CADMIUM STRESS.

GOMEZ MANSUR NABILA MARIA; SPICHAL LUKAS; NOVAK ONDRA; RECALDE LAURA; CAVAR SANJA; BENAVIDES PATRICIA; DE DIEGO NURIA; PENCIK ALEX; GALLEGO SUSANA

Congreso; IV Reunión conjunta de sociedades de biología de la República Argentina; 2020

Previous exposure of seeds/plants to certain chemicals compounds (H2O2, NO, etc.) could induce homeostasis alteration that allows them to tolerate a future abiotic stress, a phenomenon known as pre-conditioning or priming. Cadmium (Cd) is a pollutant that produces oxidative stress and interferes with the entry, transport and use of nutrients. The current work is part of a project whose principal aim is to evaluate if polyamines (PAs) applied to wheat seeds could induce a priming event and improve the response to abiotic stress produced by Cd. In order to test this, wheat seeds (Triticum aestivum L) were primed with distilled water (C) or 25µM spermine (Spm) for 3h in a shaker (120 rpm), 24 ± 2 ° C, darkness. Then seeds were germinated (30 h, 24±2°C, darkness) and afterwards 3 seedlings were transferred to each pot with vermiculite. They were carried to a growing chamber (14/10 h light/darkness, 24±2 °C, 50% relative humidity) and were watered with Hoagland ¼'s solution (C and Spm) with or without the addition of 200µM Cl2Cd (Cd and Spm-Cd). After 7d from the beginning of the experiment, they were harvested, the roots were washed with distilled water and separated from the aerial part. Results showed a significant increase in root length in Spm-Cd vs. Cd. Cd content in root and leaf was similar for Cd and Spm-Cd, while the contents of Mg, Ca, Fe and Zn were modified. The homeostasis of the free and conjugated PAs were altered in both organs by Spm and Cd. For example, Spm (with and without Cd) increased the level of cadaverine and diaminopropane (DAP) regarding C and Cd. The Spm-Cd treatment increased the activity of superoxide dismutase (SOD), guaiacol peroxidase (GPOX), the content of indol acetic acid (IAA), and decreased abscisic acid (ABA) in roots. In leaves, ABA increased in Spm-Cd regarding to the others treatments. In conclusion priming with Spm improved tolerance in presence of Cd, proved an improvement in growth, redox and hormonal balance in wheat plants. The use of priming with Spm could help a better establishment of the plant in soil, providing a better acclimatization to Cd stress.