INVESTIGADORES
PENA liliana Beatriz
congresos y reuniones científicas
Título:
Cadmium decreased root growth by inducing hormonal imbalance in maize seedlings
Autor/es:
CL MATAYOSHI; LB PENA; MS ZAWOZNIK; V ARBONA; A GÓMEZ-CADENAS; SM GALLEGO
Lugar:
Salta
Reunión:
Congreso; XIV PABMB Congress- LV Annual Meeting of the Argentinean Society for Biochemistry and Molecular Biology Research; 2019
Institución organizadora:
SAIB
Resumen:
Plant growth is controlled by redox and hormonal balance. Cadmium toxicity is closely associated to growth reduction and previous studies showed that cadmium -although is a redox inactive metal- induced redox imbalance. The objective of the present study was to evaluate root hormonal balance response to cadmium. For this purpose, Zea mays L. (maize) seeds were germinated on filter paper moistened with distilled water in plastic plates. Seedlings with roots of 1-2 cm length were selected and transferred to hydroponic culture containing diluted (1/10) Hoagland solution without (control, C) or containing 50 and 100 μM CdCl2. Plants were grown in a controlled climate room at temperature of 24 ± 2 °C in darkness. Hormonal determinations were performed after 72 h of treatment. Moreover, global SUMO1 and ubiquitin (Ub) proteins conjugation were assayed. The root apex (5 mm) segment (A) and the rest of the root tissue (R) were processed separately. Cadmium decreased root length (66 and 70 % for 50 and 100μM CdCl2, respectively) respect to the C. Jasmonic acid (JA) concentration remained similar to C, but JA-isoleucine conjugate (JA-Ile) was significantly reduced in both, A (81 and 91% for 50 and 100μM CdCl2) and R (74 and 64% for 50 and 100μM CdCl2). Gibberellins (GA) GA4 content significantly decreased in A (63 and 80% for 50 and 100μM CdCl2) as well as in R (65 and 47% for 50 and 100μM CdCl2). The precursor GA20 was markedly enhanced in R by about 53% (without difference between concentrations), whereas GA3 and GA7 levels remained similar to C. On the other hand, indole-3-acetic acid increased significantly in a dose-dependent manner in both, A (27 and 82% for 50 and 100μM CdCl2) and R (200 and 350% for 50 and 100μM CdCl2). Furthermore, abscisic acid content increased in A (181 and 80% for 50 and 100μM of CdCl2 respectively) but more remarkable in R (418 and 649% for 50 and 100μM CdCl2). Finally, salicylic acid showed an increment of 89% in the A under 50μM of CdCl2, but a reduction of 33% with 100μM of CdCl2. Global SUMO1- and Ub-conjugated proteins were increased in A, but decreased in R during the metal treatment. Summing up, cadmium induced not only redox but also hormonal imbalance, which led to root growth inhibition. Furthermore, protein conjugation with SUMO and Ub modifiers upon Cd-exposure would be involved as part of a general cell defence mechanism against metal toxicity.