Effects of aluminum on the physiology and biochemistry of shoots of Eucalyptus grandis x E. urophylla cultivated in vitro

elementos considerados tóxicos para as plantas, como o alumínio, levando a baixo pH do solo e prejudicando a disponibilidade de outros nutrientes minerais. O objetivo deste trabalho foi avaliar o efeito do alumínio na fisiologia e bioquímica de brotações de Eucalyptus grandis x E. urophylla, cultivadas in vitro, consistindo-se de parte aérea pouco desenvolvida e ausência de sistema radicular. O experimento foi delineado inteiramente casualizado, com quatro tratamentos e quatro repetições por tratamento. Cada tratamento correspondeu a 0; 0,25; 0,5 e 1,0 mM de Al Cl3.6H2O. As coletas foram realizadas aos 4, 8, 12, 16, 20, 24 e 28 dias de cultivo, avaliando-se a concentração dos nutrientes no material vegetal após o período de cultivo, a curva de crescimento do clone, atividade da enzima fosfatase ácida, o efeito do alumínio no metabolismo das poliaminas (putrescina, espermidina e espermina) e quantificação do teor de proteínas solúveis totais. Pela análise dos resultados, pode-se concluir que a adição de AlCl3.6H2O alterou o meio de cultura, indisponibilizando principalmente os nutrientes cálcio, fósforo e potássio, reduzindo a absorção dos mesmos pela planta e com isso, alterou o metabolismo celular, principalmente em processos altamente dependentes destes elementos, ocasionando perdas de estrutura, maior atividade de fosfatase ácida, acúmulo de poliaminas e redução do teor de proteínas solúveis totais. O estudo mostrou que usando a técnica de cultivo in vitro é possível estudar os mecanismos de adaptação das plantas a solos que contém problemas com toxidez de alumínio.The forest activity is generally developed in low fertility soils, usualIy with mineral toxicity, mainly aluminum, low soil pH changes in the availability of other mineral nutrients. The aim of this work was to evaluate the effects of aluminum on the physiology and biochemistry of Eucalyptus grandis x E. urophylla epicormic shoots cultivated in vitro. The trial was established using a statistical design completely randomized, with four treatments, four replicates for alI evaluated variables. Each treatment corresponded to 0; 0.25; 0.5 and 1.0 mM of AlCl3.6H2O. The data were collected at 4, 8, 12, 16, 20, 24 and 28 days of culture, evaluating the mineral nutrient content, the clone relative growth rate, the acid phosphatase activity, the polyamines contents (putrescine, spermidine and spermine) and total soluble protein content. The analysis of the results showed that the addiction of the AlCl3.6H2O changed the culture medium, reduced calcium, phosphate and potassium availability and absorption. The cell metabolism was changed mainly in process highly dependent on these nutrients, leading to structural losses, higher acid phosphatase activity, increase in polyamines content and reduced total soluble protein content

Efeito do alumínio no crescimento de brotações de Eucalyptus grandis x E. urophylla cultivadas in vitro

The aim of this work was to evaluate the effects of aluminum on the growth of Eucalyptus shoots cultivated in vitro through nutrient and total soluble protein content. The trial had a totally randomized design with four treatments and four replicates. The treatments were: 0.0; 0.25; 0.5 and 1.0 mM of AlCl 3.6H 2O. Shoots without roots of a Eucalyptus grandis x E urophylla clone were used for the in vitro culture. Evaluations were made on the 4th, 8th, 12th, 16th, 20th, 24th and 28th day of culture. The Al addition to the culture media reduced mainly Ca, P and K availability and absorptions by the shoots. The cellular metabolism was affected, conducted to morphological alterations in shoots (browning, mass calluses formation and shoots not friable), dry matter increased and a decreased in total protein soluble

Efeito do alumínio no conteúdo de poliaminas livres e atividade da fosfatase ácida durante o crescimento de brotações de Eucalyptus grandis × E. urophylla cultivadas in vitro

This paper is aiming to evaluate the effects of different levels of the aluminum on the growth of the Eucalyptus grandis x E. urophylla shoots cultivated in vitro. Evaluations were carried out on pH and chemicals modifications of the culture medium by Geochem program, polyamines contents (putrescine, espermidine e espermine) and acid phosphatase ativity on the shoots. The trial had a totally randomized design with four treatments and four replicates. The treatments were: 0.0, 6.75,13.50 and 27 mg.L -1 of AlCl 3.6H 2. Evaluations were carried out on the 4th, 8th, 12th, 16th, 20th, 24th and 28th day of culture. The addition of the aluminium, in all concentrations, affected the culture medium ionic equilibrium, the morphology of the shoots, reduced the pH on the medium, induced an increase in polyamines content and higher acid phosphatase activity