Bacteria that colonize the leaves of terrestrial plants often occur in clusters whose size varies from a few to thousands of cells. For the formation of such bacterial clusters, two non-mutually exclusive but very different mechanisms may be proposed: aggregation of multiple cells or clonal reproduction of a single cell. Here we assessed the contribution of both mechanisms on the leaves of bean...

Adviser: Brigitte Tenhumberg Food acquisition is a complicated task. The profitability of potential food items depends on numerous factors, including the spatial distribution, probability of detection and capture, and suitability of the food. Animals faced with such challenges can use relatively simple mechanisms to maximize foraging efficiency. However, mechanisms that maximize foraging effici...

Protein-energy malnutrition is the most serious nutritional body depletion disorder among infants and young children in developing countries, attributable to inadequate energy and nutrient intake, partly due to high dietary bulk of weaning and infant foods. The gruels fed to children are typically of low nutrient and energy density due to the low flour incorporation rate required for drinking v...

The objective of the present work was to determine the effect of NH4NO3 toxicity on nitrogen metabolism in Phaseolus vulgaris L. cv. Strike. The NH4NO3 was applied to the nutrient solution at 6 (N1), 12 (N2), 18 (N3), and 24 mM (N4). The availability of NO3− and NH4+ in the roots and leaves of green bean proved to be influenced by the different NH4NO3 treatments, being the NO3− and NH4+ translo...

Climate changes, mostly related to high temperature, are predicted to have major negative impacts on coffee crop yield and bean quality. Recent studies revealed that elevated air [CO2] mitigates the impact of heat on leaf physiology. However, the extent of the interaction between elevated air [CO2] and heat on coffee bean quality was never addressed. In this study, the single and combined impac...

Histone proteins were studied by microphotometry of plant tissue sections stained with fast green at pH 8.1. For comparative purposes the Feulgen reaction was used for deoxyribose nuclei acid (DNA); the Sakaguchi reaction for arginine; and the Millon reaction for estimates of total protein. Analysis of Tradescantia tissues indicated that amounts of nuclear histone fell into approximate multiple...

The calcium content and distribution across the abscission zones of (2-chloroethyl) phosphonic acid-treated bean (Phaseolus vulgaris L. var. Contender) leaves were lower and not uniformly distributed as compared to the control. Calcium chloride-treated bean leaves had a higher calcium content, with more calcium localized in the potential abscission layer. Ethephon treatment promoted abscission ...