Molybdenum for Plants: Detoxification of Nitrates
Molybdenum (Mo)
For the plant – detoxification of nitrates.
In the plant organism molybdenum is a component of enzymes, under the action of which the reduction of nitrate nitrogen occurs in cells (nitrate reductases, nitrogenases, oxidases, and molybdoferredoxins), plays a significant role in nitrogen metabolism and the synthesis of protein substances, facilitates the absorption of nitrogen dissolved in water, nitrogen fixation, participates in the synthesis of nucleic acids and in various redox reactions.
Under the influence of molybdenum, the content of carbohydrates, carotene, ascorbic acid, protein substances, chlorophyll increases in plants, and the intensity of photosynthesis rises.
The content of molybdenum in plants ranges from 0.001 to 0.1 mg% (on a dry matter basis). It accumulates mainly in young growing organs (seeds of plants are particularly rich in it).
In case of molybdenum deficiency in plants, a large amount of nitrates accumulates, spots appear on old and medium-aged leaves, their edges curl upwards, small veins lose their green color, and bright yellow spots form between the veins. Molybdenum is especially important for leguminous plants, as it concentrates in the nodules of legumes, promoting their formation.
Large doses of molybdenum are highly toxic to plants. Excess molybdenum causes spotting in tomatoes and leaf filaments in cauliflower.
Plants that produce cardiac glycosides and saponins selectively accumulate molybdenum.
Plants that are super-accumulators of molybdenum include:
• marsh ledum Ledum palustre L., Ericaceae (shoots);
• species of the genus astragal Astragalus L., Fabaceae (herb);
• medicinal sweet clover Melilotus officinalis (L.) Pall., Fabaceae (herb);
• bird knotweed (= common knotgrass) Polygonum aviculare L., Polygonaceae (herb);
• buckthorn Rhamnus cathartica L., Rhamnaceae (fruits);
• stinging nettle Urtica dioica L., Urticaceae (leaves);
• peppermint Mentha piperita L., Lamiaceae (leaves).
• marsh ledum Ledum palustre L., Ericaceae (shoots);
• species of the genus astragal Astragalus L., Fabaceae (herb);
• medicinal sweet clover Melilotus officinalis (L.) Pall., Fabaceae (herb);
• bird knotweed (= common knotgrass) Polygonum aviculare L., Polygonaceae (herb);
• buckthorn Rhamnus cathartica L., Rhamnaceae (fruits);
• stinging nettle Urtica dioica L., Urticaceae (leaves);
• peppermint Mentha piperita L., Lamiaceae (leaves).
Medicinal plants containing molybdenum:
• species of hellebore Helleborus L., Ranunculaceae (rhizome with roots);
• common barberry Berberis vulgaris L., Berberidaceae (roots, leaves, fruits, content in ash of fruits – 0.1 mg%);
• lesser periwinkle Vinca minor L., Apocynaceae (herb);
• spring adonis Adonis vernalis L., Ranunculaceae (herb);
• lily of the valley Convallaria majalis L., Convallariaceae (leaves, herb, flowers);
• purple foxglove Digitalis purpurea L., woolly foxglove Digitalis lanata Ehrh., Scrophulariaceae (leaves);
• gray wallflower Erysimum canescens Roth., Brassicaceae (herb);
• species of strophanthus Strophanthus DC., Apocynaceae (seeds);
• species of rosehip Rosa L., Rosaceae (fruits, content in ash – 0.1–0.6 mg%);
• species of hawthorn Crataegus L., Rosaceae (fruits, content in ash – 0.3–0.5 mg%);
• rowan Sorbus aucuparia L., Rosaceae (fruits, content in ash – 0.1 mg%);
• common viburnum Viburnum opulus L., Caprifoliaceae (fruits, content in ash – 0.1 mg%);
• black elderberry Sambucus nigra L., Caprifoliaceae (fruits, content in ash – 0.2 mg%).
• species of hellebore Helleborus L., Ranunculaceae (rhizome with roots);
• common barberry Berberis vulgaris L., Berberidaceae (roots, leaves, fruits, content in ash of fruits – 0.1 mg%);
• lesser periwinkle Vinca minor L., Apocynaceae (herb);
• spring adonis Adonis vernalis L., Ranunculaceae (herb);
• lily of the valley Convallaria majalis L., Convallariaceae (leaves, herb, flowers);
• purple foxglove Digitalis purpurea L., woolly foxglove Digitalis lanata Ehrh., Scrophulariaceae (leaves);
• gray wallflower Erysimum canescens Roth., Brassicaceae (herb);
• species of strophanthus Strophanthus DC., Apocynaceae (seeds);
• species of rosehip Rosa L., Rosaceae (fruits, content in ash – 0.1–0.6 mg%);
• species of hawthorn Crataegus L., Rosaceae (fruits, content in ash – 0.3–0.5 mg%);
• rowan Sorbus aucuparia L., Rosaceae (fruits, content in ash – 0.1 mg%);
• common viburnum Viburnum opulus L., Caprifoliaceae (fruits, content in ash – 0.1 mg%);
• black elderberry Sambucus nigra L., Caprifoliaceae (fruits, content in ash – 0.2 mg%).