Structural and Functional Evaluation of Humic Acids in Interaction with Toxic Metals in a Cultivar of Agricultural Interest/Avaliacao estrutural e funcional dos acidos humicos na interacao com metais toxicos em um cultivar de interesse agricola
There are plants with the capacity to tolerate stress conditions due to toxic metals by developing mechanisms that allow them to maintain homeostasis. The purpose of this paper was to verify, after the addition of humid acids, as possible stimulators of these mechanisms, the activity of phenylalanin...
Gespeichert in:
Veröffentlicht in: | Revista ciencias técnicas agropecuarias 2017-07, Vol.26 (3), p.39 |
---|---|
Hauptverfasser: | , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | There are plants with the capacity to tolerate stress conditions due to toxic metals by developing mechanisms that allow them to maintain homeostasis. The purpose of this paper was to verify, after the addition of humid acids, as possible stimulators of these mechanisms, the activity of phenylalanine-ammonium-liase and nitrate reductase enzymes, content of total nitrate, proline, (as components both of the antioxidant system of bean) as well as nitrogen, in plants subjected to stress by [Pb.sup.2+]. Bean seeds were planted in a typical red Ferrallitic soil, artificially contaminated with 100 mg [kg.sup.-1] of [Pb.sup.2+]. Fifteen days after germination, the plants were treated with humic acid solutions at concentrations of 20, 40 and 60 mg [L.sup.-1] through foliar spraying, on the first and first trifoliate leaves. Every fifteen days enzyme activities were analyzed. Results showed a decrease of biochemical-physiological effects caused by [Pb.sup.2+] in the enzymatic systems of plants treated with humic acids, stating categorically that they may mitigate the stress provoked by metals in the phenological stages evaluated in bean crop, being 40 mg [L.sup.-1] the most prominent dosage. Keywords: humic substance, oxidative stress, defense mechanism RESUMO. Existem plantas que tem a capacidade de tolerar condições de estresse por metais tóxicos, desenvolvendo mecanismos que permitem manter a homeostase. Objetivou-se com o presente trabalho verificar a partir da adição de ácidos húmicos - como possíveis estimuladores destes mecanismos - a atividade das enzimas fenilalanina-amonio-liase, nitrato reductase, conteúdo de nitratos totais e prolina, como componentes tanto do sistema de defensa antioxidante de plantas de feijão como do nitrogênio, submetidas a estresse por [Pb.sup.2+]. Sementes de feijão foram semeadas num solo Ferralítico vermelho típico contaminado artificialmente com 100 mg [kg.sup.-1] de [Pb.sup.2+]. Após 15 dias de germinadas, as plantas foram tratadas com soluções de ácidos húmicos nas concentrações de 20, 40 e 60 mg [L.sup.-1] mediante aspersäo foliar na folha primária e na primeira folha trifoliolada e a cada 15 dias foram analisadas a atividade das enzimas. Os resultados evidenciaram uma atenuação dos efeitos bioquímico-fisiológicos causados pelo [Pb.sup.2+] nos sistemas enzimáticos das plantas tratadas com ácidos húmicos, concluindo que os mesmos podem amenizar o estresse provocado pelo metal nas fases fenológicas avaliadas no cultivo do feij |
---|---|
ISSN: | 1010-2760 |