Efeito do alumínio sobre compostos nitrogenados em Urochloa spp.

Abstract

ResumoA superfície terrestre apresenta, em sua composição, aproximadamente 7% de alumínio (Al), na forma de óxidos de alumínio ou aluminossilicatos, entretanto, sua disponibilidade é extremamente dependente do pH do solo. O cerrado é um bioma que apresenta solos com pH baixo e possui grande quantidade de Al +3 disponível; dessa forma, a produção vegetal pode se tornar limitada. Os vegetais possuem mecanismo para tolerar quantidades excessivas de Al +3 no solo; um dos mecanismos utilizados para esse propósito é a exsudação de ácidos orgânicos, que são capazes de formar complexos com o Al +3 , e, assim, ele se torna indisponível para as plantas. Uma vez disponível, o Al +3 pode afetar o metabolismo de nitrogênio (N), levando a perdas na produção. Portanto, este estudo teve por objetivo avaliar o efeito do Al +3 sobre compostos relacionados ao metabolismo de N em três espécies do gênero Urochloa (U. brizantha, U. decumbens e U. humiducola). O delineamento experimental foi inteiramente casualizado em esquema fatorial 2 x 3 (com e sem Al +3 e 3 espécies de Urochloa); a dose de Al AbstractAluminum effect on nitrogenous compounds in Urochloa spp. Earth's surface has, in its composition, around 7% of aluminum (Al), in the form of aluminum oxides or aluminosilicates, however, its availability is greatly dependent on soil pH. Cerrado is a biome presenting low pH soils and it has high amounts of Al +3 available; thus, plant production may become limited. Plants have mechanism to tolerate excessive amounts of Al +3 in soil; one of the mechanisms used for this purpose is the exudation of organic acids, which are able to form complexes with Al +3 , and, thus, it becomes unavailable to plants. Once

Aluminum stress differentially affects physiological performance and metabolic compounds in cultivars of highbush blueberry

“…It has been documented that Al causes harmful effects in the assimilation of nitrogen and impacts nitrogen metabolism as a whole 55,56 . Besides, Al-tolerant plants growing in acid soils prefer NH 4 + to NO 3 − forms, whereas those growing in neutral or calcareous soils are Al-sensitive and prefer NO 3 − to NH 4 + 57,58 .…”

Nitrogen compounds, proteins and amino acids in corn subjected to doses of aluminum

“…In addition, aluminum can cause harmful effects in the assimilation of nitrogen in the plants (Pal'ove- Balang and Mistrik, 2011). That causes a reduction in the concentration of nitrate in the presence of aluminum (Souza et al, 2014). Thus, high concentrations of this element cause alterations in the biochemical process of nitrogen, which is considered important in the production of the protein precursor (Camargo and Almeida, 1983;Sphear and Souza, 2004).…”

Impact of Aluminum Toxicity on Physiological Aspects of Barley (Hordeum vulgare L.) Cultivars and its Alleviation through Ascorbic Acid and Salicylic Acid Seed Priming

“…Al also reduces the enzymatic activity of carbohydrate metabolism. Sucrose synthase and Invertase are important enzymes thatcauses a reduction in nitrate concentration (Souza et al, 2014). Al alters protein and amino acid content due to changes in enzymes of protein metabolism (Azmat et al, 2015).…”