Growth modifications and oxidative stress in seedlings of different maize hybrids subjected to cadmium and copper stress

CL MATAYOSHI; EA HERNÁNDEZ; M LOIS; MP BENAVIDES; LB PENA; SM GALLEGO

Buenos Aires

Congreso; 2da Reunión Conjunta de Sociedades de BioCiencias; 2017

10 Sociedades Científicas de nuestro país

Maize is one of the most important agronomical crops. It is used in the human diet and it is considered an interesting source for the production of biofuels. Since early seedling growth is critical in plant life cycle, the effect of Cd (a redox inactive metal) and Cu (a redox active metal) on growth parameters of 10 commercial Zea mays L. hybrids (labelled H1 to H10) was analyzed at this stage. Maize seeds were germinated on filter paper in plastic dishes containing distilled water. Seedlings of a comparable size with roots of 1-2 cm length were selected and transferred to hydroponic culture without (control, C) or containing an aqueous solution of 100 μM CdCl2 or CuCl2. They were grown in a controlled climate room at 24±2°C in darkness during 72 h. For statistical analysis of growth parameters, a hierarchical model factorial design was applied, taking ?H? as factor A, and ?treatments (C, Cd, Cu)? as factor B nested in A. Despite metals significantly decreased root and coleoptile length, fresh and dry weight, no statistically significant interaction was detected between genotypes and metals treatment. Metals increased oxidative protein damage in roots and decreased transcript accumulation of the gene family from the enzyme methionine sulfoxide reductase (MSR): ZmMSRA4, ZmMSRA5.1, ZmMSRB1, ZmMSRB5.1 in the root apex. Further analysis in root apex of H10 showed that protein conjugation pattern with SUMO and ubiquitin were modified during metal treatment. In addition to previous data obtained in our laboratory, the present results indicate that the oxidative posttranslational modifications (PTM) produced during abiotic stress could be a nexus between stress recognition and growth reprogramming. Despite further studies are needed, we propose that this could be an interesting mechanism where oxidative PTM regulates another PTMs like sumoylation and ubiquitination as part of the signalling process during abiotic stress.Keywords: Maize, Abiotic Stress, Metals, Oxidative posttranslational modification