Vermicomposts present a high content of humic substances and their effects on soil properties are well-documented. However, direct effects of humic substances on plant metabolism are less known. The aim of this work was to evaluate the use of humates isolated from cattle manure vermicompost with 0.1 mol L-1 KOH on root growth and ATP metabolism of lettuce seedlings. After germination, lettuce seedlings were treated with different humate concentrations (0 to 100 mg L-1 of C) for 15 days. The root growth and the H+-ATPase […]

Cattle manure availability is one of the most limiting factors for vermicompost production. The effects of the partial substitution of manure with sugarcane bagasse or residues of Gliricidia sepium on the quality of vermicomposts and the bioactivity of their humates were evaluated by analyzing the root growth and H+-ATPase activity of lettuce seedling roots. The substitutions of manure by sugar cane bagasse and legume cover crops residues did not affect the chemical properties of humates. Humates isolated from the different […]

The influence of two species of arbuscular mycorrhizal fungi (AMF) on the ATPase and pyrophosphatase activities of corn root microsomes was investigated at 20, 30, 40, and 60 days after planting. The microsomes were isolated by cell fractionation from corn roots colonized with Glomus clarum or Gigaspora margarita. Both fungi led to a significant increase in the ATPase and pyrophosphatase activities though the highest activities were observed in roots colonized with G. clarum. Kinetics analysis suggested that mycorrhizal colonization promoted a […]