Uma abordagem sobre os mecanismos de tolerância ao alumínio e papel mitigador do silício em milho pipoca

Abstract

The cultivation of popcorn maize (Zea mays L. var. everta) is widely intended for human consumption, but its productivity can be affected in acidic soils, where aluminum (Al) toxicity is a problem. In this study, we investigated the effects of Al on two popcorn maize lineages: 11-133, Al-tolerant, and 11-60, Al-sensitive. We observed that Al did not affect the shoot growth, but it caused yellowing in the older leaf blade of the sensitive lineage. The tolerant lineage showed Al chelation mechanisms, resulting in minor alterations in the root structure and lower presence of reactive oxygen species (ROS) and malondialdehyde (MDA), which is attributed to a more efficient enzymatic system, mainly due to the glutathione (GSH) metabolism. In the second experiment, we investigated the mitigating role of silicon (Si) against Al in popcorn plants. We observed that in the presence of Al there was a reduction in the root growth rate, but the addition of Si mitigated this negative effect, resulting in a reduction in the Al concentration in at root tips and a lower morphoanatomical impact. Si also modulated the metabolism of plants exposed to Al, increasing fructose, sucrose, total amino acids, and nitrate concentrations, while total protein concentrations decreased in Si-treated plants. These results indicate the potential of Si as a strategy to improve the development of crops in acidic soils and mitigate the negative effects of Al toxicity on popcorn plants.