SEED HEAT-PRIMING INDUCES CHANGES IN ANTIOXIDANT SYSTEM IN MAIZE SEEDLINGS

ML EGGEL; MV PÉREZ CHACA; LB PENA

Mendoza

Congreso; XL Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

Sociedad de Biología de Cuyo

In addition to soil moisture, an abiotic factor that influences seed germination is temperature. Different priming techniques: osmo, hydro, chemical, hormonal and nutrient techniques have been used to improve seed germination and crop yield. The increased levels of carbon dioxide (CO2) trigger a rise in temperatures and an increase of drought episodes, causing climate change. Seeds between harvest and sowing may experience temperature increases for short periods during storage. Our objective was to evaluate the redox state during post-germinative seedling development after heat-priming of maize seeds. Maize seeds (Zea mays L.) variety NS 7818 VIP3 from Nidera were subjected to pretreatment with 40 or 50 °C for 3 and 7 d. Seeds with and without heat-priming were superficially disinfected, and germinated on cotton and paper towels saturated with distilled water at 28 °C for 96 h. The determinations were made using the apical 2 cm of the roots. Ascorbate peroxidase (APX) and catalase (CAT) activities were determined as ascorbic and H2O2 consumed respectively. Lipid peroxidation was quantified by measuring the thiobarbituric acid reactive substances (TBARS). Root growth was induced by heat-priming at 40 °C in maize seedlings. Pretreatments disrupted cellular redox balance, modifying antioxidant enzyme activities. All pretreatments induced at least 2 fold the APX activity significantly (P