Titanium for Plants: A Helper in Nitrogen Fixation
Titanium (Ti)
For the plant – a helper in nitrogen fixation
Titanium is constantly present in the tissues of plants and animals. In terrestrial plants, its concentration is about 10–4%, in marine plants – from 1.2 • 10–3 to 8 • 10–2%, in the tissues of terrestrial animals – less than 2 • 10–4%, and in marine animals – from 2 • 10–4 to 2 • 10–2%.
There is little clear evidence of the biological role of titanium in the plant organism, although its possible catalytic function in nitrogen fixation by symbiotic microorganisms, in the photo-oxidation of nitrogen compounds in higher plants, and in some processes of photosynthesis has been described.
An increase in chlorophyll content has been noted in tomato plants grown hydroponically after spraying them with a titanium chelate solution.
It is believed that titanium has relatively low biological availability for plants and moves poorly within them.
The levels of titanium content in plants vary from 0.15 to 80 mg/kg of dry weight.
Symptoms of titanium excess toxicity for plants have been described, among which are chlorotic and necrotic spots observed on leaves (manifesting at titanium concentrations above 200 mg/kg of dry weight).
Titanium hyperaccumulator plants:
• species of the genus horsetail Equisetum L., Equisetaceae (herb);
• stinging nettle Urtica dioica L., Urticaceae (leaves);
• diatoms Bacillariophyta Haeckel (thalli, content – from 15 to 1500 mg/kg).
• species of the genus horsetail Equisetum L., Equisetaceae (herb);
• stinging nettle Urtica dioica L., Urticaceae (leaves);
• diatoms Bacillariophyta Haeckel (thalli, content – from 15 to 1500 mg/kg).
Medicinal plants containing titanium:
• common barberry Berberis vulgaris L., Berberidaceae (roots, leaves, fruits, content in fruits – 0.07 mg%);
• common ginseng Panax ginseng CAMey., Araliaceae (roots);
• species of hawthorn Crataegus L., Rosaceae (fruits, depending on the species, content ranges from 0.36 to 0.96 mg%);
• black elderberry Sambucus nigra L., Sambucaceae (fruits, content – 0.02–0.05 mg%);
• spherical cladophora Cladophora aegagropila (L.) Trev., Cladophoraceae, division green algae Chlorophyta (titanium content in thallus exceeds 0.03%).
• common barberry Berberis vulgaris L., Berberidaceae (roots, leaves, fruits, content in fruits – 0.07 mg%);
• common ginseng Panax ginseng CAMey., Araliaceae (roots);
• species of hawthorn Crataegus L., Rosaceae (fruits, depending on the species, content ranges from 0.36 to 0.96 mg%);
• black elderberry Sambucus nigra L., Sambucaceae (fruits, content – 0.02–0.05 mg%);
• spherical cladophora Cladophora aegagropila (L.) Trev., Cladophoraceae, division green algae Chlorophyta (titanium content in thallus exceeds 0.03%).
The titanium content in the fruits of various hawthorn species ranges from 0.36 to 0.96 mg%, in common barberry – 0.07 mg%, and in black elderberry – 0.05–0.02 mg%.