Resumen:
Purpose We investigated the interactive role of Si-mediated attenuation to aluminum (Al) toxicity in two sugarcane cultivars
(‘CTC9002’ and ‘CTC9003’) grown in hydroponic conditions.
Methods Two pot experiments were distributed in randomized blocks in a factorial design (4 × 2) with four replications. The
treatments consisted of 0, 10, 15, and 20 mg L−1 Al (as aluminum sulfate [Al2 (SO4)3·18H2O)], which were combined with the
absence and presence of Si [(2.0 mmol L−1 as potassium silicate (K2SiO3)].
Results Both sugarcane cultivars (‘CTC9002’ and ‘CTC9003’) were affected by Al toxicity (above 10 mg L−1), resulting in
nutritional disorders and decreasing plant growth, which were drastically reversed by Si addition in the growth medium. Si supplementation
decrease Al concentration and translocation to the shoots of both cultivars when Al and Si were simultaneously supplied in
the growth medium. We demonstrated that in shoots of both sugarcane seedlings, Si concentration are positively related to the lignin
concentrations (ranging from 12.0% to 41% in cv. ‘CTC9002’ and 12% to 47% in cv. ‘CTC9003’). In addition, Si fertilization
enhanced mineral nutrition and use efficiency of macros- and micronutrients, irrespective of the cultivar. Therefore, the use of cultivar
‘CTC9003’ under Si fertilization is more recommended to cope with the adverse effect caused by Al stress.
Conclusions The findings of this study suggest that Si fertilization in sugarcane seedlings is an economic and viable strategy
strongly recommended to cope with the adverse effect caused by Al toxicity at concentrations less than 20 mg L−1, which lead to
increase the shoot biomass production.
