72 research outputs found
Proposed physiologic functions of boron in plants pertinent to animal and human metabolism.
Boron has been recognized since 1923 as an essential micronutrient element for higher plants. Over the years, many roles for boron in plants have been proposed, including functions in sugar transport, cell wall synthesis and lignification, cell wall structure, carbohydrate metabolism, RNA metabolism, respiration, indole acetic acid metabolism, phenol metabolism and membrane transport. However, the mechanism of boron involvement in each case remains unclear. Recent work has focused on two major plant-cell components: cell walls and membranes. In both, boron could play a structural role by bridging hydroxyl groups. In membranes, it could also be involved in ion transport and redox reactions by stimulating enzymes like nicotinamide adenine dinucleotide and reduced (NADH) oxidase. There is a very narrow window between the levels of boron required by and toxic to plants. The mechanisms of boron toxicity are also unknown. In nitrogen-fixing leguminous plants, foliarly applied boron causes up to a 1000% increase in the concentration of allantoic acid in leaves. In vitro studies show that boron inhibits the manganese-dependent allantoate amidohydrolase, and foliar application of manganese prior to application of boron eliminates allantoic acid accumulation in leaves. Interaction between borate and divalent cations like manganese may alter metabolic pathways, which could explain why higher concentrations of boron can be toxic to plants
Constituyentes del aceite esencial de Lavándula Lanata Boiss
We studied the essential oil of Lavandula Lanata Boiss, in which thirty four substances were identified, camphor, lavandulol and 3-octanone being the most abundant of them. The percentages of these compounds were found to vary considerably depending on the vegetative stage on which the plant was collected.Hemos estudiado la composición química del aceite esencial de Lavandula Lanata Boiss, habiendo identificado treinta y cuatro sustancias, de las cuales, lavandulol, 3-octanona y alcanfor son las más abundantes. Se ha encontrado que el porcentaje de estos componentes varía considerablemente en función de la época de recogida de la planta
Constituyentes del aceite esencial de Lavándula Lanata Boiss
Hemos estudiado la composición química del aceite esencial de Lavandula
Lanata Boiss, habiendo ·identificado treinta y cuatro sustancias, de las cuales,
lavandulol, 3-octanona y alcanfor son las más abundantes. Se ha encontrado
que el porcentaje de estos componentes varía considerablemente en función
de la época de recogida de la planta.We studied the essential oil of Lavandula Lanata Boiss, in which thirty
four substances were identified, camphor, lavandulol and 3-octanone being the
most abundant of them. The percentages of these compounds were found to
vary considerably depending on the vegetative stage on which the plant was
collected
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