Nickel for Plants: Nitrogen Supply
Nickel (Ni)
For the plant – nitrogen supply.
Nichel is an essential micronutrient for plants. In higher plants, nickel is included in the composition of the enzyme urease, which catalyzes the breakdown of urea into ammonia and carbon dioxide. It has been shown that in nickel-sufficient plants, urease activity is higher and, consequently, urea content is lower compared to nickel-deficient plants. Nickel activates a number of enzymes, including nitrate reductase, hydrogenase, and others, exerts a stabilizing effect on the structure of ribosomes, participates in the movement of nitrogen, and ensures its supply to plant tissues.
A number of experiments have established the positive effect of nickel application to the soil on the yield of agricultural crops, which is likely due to the stimulation of microbiological processes of nitrification and mineralization of nitrogen compounds in the soil.
The first indications of nickel’s presence in plants were made by V.I. Vernadsky. Nickel enters plants in the form of the ion Ni2+, but can also exist as Ni+ and Ni3+.
Typically, the nickel content in plants does not exceed 0.005 mg% (by weight), but some plants (for example, tea, cocoa, buckwheat, carrot, lettuce) contain it in significant amounts. Microorganisms also concentrate nickel, which can contain thousands and even hundreds of thousands of times more nickel than the surrounding environment.
Nickel deficiency leads to a decrease in plant growth rates and a reduction in biomass accumulation.
Nickel toxicity manifests as suppression of photosynthesis and transpiration processes, and the appearance of signs of leaf chlorosis. Excess nickel is the cause of the appearance of “boang” (literally – “empty nuts”) – a disease of coconut palms in Hawaii – and can cause flower reduction, for example, in the open-flowered Anemone.
Sources of nickel include the fruits and leaves of wild plants.
Nickel hyperaccumulator plants include:
• Bertoloni’s alyssum Alyssum bertolonii Desv., Brassicaceae (herb, content – 0.8% of dry weight and 11% in ash)
• floribundus hybanthus Hybanthus floribundus (Lindl.) F. Muell., Violaceae (herb, content in ash – 23%).
• Bertoloni’s alyssum Alyssum bertolonii Desv., Brassicaceae (herb, content – 0.8% of dry weight and 11% in ash)
• floribundus hybanthus Hybanthus floribundus (Lindl.) F. Muell., Violaceae (herb, content in ash – 23%).
Medicinal plants containing nickel:
• marshmallow Althaea officinalis L., Malvaceae (roots);
• greater burnet Sanguisorba officinalis L., Rosaceae (roots);
• field restharrow Ononis arvensis L., Fabaceae (roots);
• deadly nightshade Atropa belladonna L., Solanaceae (rhizomes with roots, herb, leaves);
• yellow horned poppy Glaucium flavum Crantz, Papaveraceae (herb);
• passionflower Passiflora incarnata L., Passifloraceae (herb);
• lance-leaved thermopsis Thermopsis lanceolata R.Br., Fabaceae (herb);
• motherwort Leonurus quinquelobatus Gilib. and heartwort Leonurus cardiaca L., Lamiaceae (herb);
• peppermint Mentha piperita L., Lamiaceae (leaves);
• rowan Sorbus aucuparia L., Rosaceae (fruits, content – 1–2 mg%);
• common apple Malus domestica Borkh., Rosaceae (leaves, content in ash – 2 mg%, absent in fruits);
• species of hawthorn Crataegus L., Rosaceae (flowers);
• Chinese magnolia vine Schisandra chinensis (Turcz.) Baill., Schisandraceae (fruits);
• common viburnum Viburnum opulus L., Caprifoliaceae (leaves – 1 mg%; fruits – 0.01 mg%);
• common barberry Berberis vulgaris L., Berberidaceae (fruits – 5 mg%);
• black elder Sambucus nigra L., Caprifoliaceae (fruits – 1–2 mg%);
• species of juniper Juniperus L., Cupressaceae (fruits).
• marshmallow Althaea officinalis L., Malvaceae (roots);
• greater burnet Sanguisorba officinalis L., Rosaceae (roots);
• field restharrow Ononis arvensis L., Fabaceae (roots);
• deadly nightshade Atropa belladonna L., Solanaceae (rhizomes with roots, herb, leaves);
• yellow horned poppy Glaucium flavum Crantz, Papaveraceae (herb);
• passionflower Passiflora incarnata L., Passifloraceae (herb);
• lance-leaved thermopsis Thermopsis lanceolata R.Br., Fabaceae (herb);
• motherwort Leonurus quinquelobatus Gilib. and heartwort Leonurus cardiaca L., Lamiaceae (herb);
• peppermint Mentha piperita L., Lamiaceae (leaves);
• rowan Sorbus aucuparia L., Rosaceae (fruits, content – 1–2 mg%);
• common apple Malus domestica Borkh., Rosaceae (leaves, content in ash – 2 mg%, absent in fruits);
• species of hawthorn Crataegus L., Rosaceae (flowers);
• Chinese magnolia vine Schisandra chinensis (Turcz.) Baill., Schisandraceae (fruits);
• common viburnum Viburnum opulus L., Caprifoliaceae (leaves – 1 mg%; fruits – 0.01 mg%);
• common barberry Berberis vulgaris L., Berberidaceae (fruits – 5 mg%);
• black elder Sambucus nigra L., Caprifoliaceae (fruits – 1–2 mg%);
• species of juniper Juniperus L., Cupressaceae (fruits).