Differences in ionomic responses to nutrient deficiencies among plant species under field conditions.

The ionome is defined as the mineral element composition of an organism or tissue and is genetically and environmentally influenced. Although nutrient deficiency changes the plant ionome, the differences among different species have not been elucidated fully. In the present study, we examined the ionomic responses to nutrient deficiency in wheat (Triticum aestivum L.), maize (Zea mays L.), sunflower (Helianthus annuus L.), and soybean (Glycine max (L.) Merr.) to understand the differences in response to nutrient deficiency among different plant species. The plants were cultivated in fields with four fertilizer treatments: complete fertilization, without nitrogen, without phosphorus, and without potassium. Each plant species was sampled just before the flowering stage, and mineral concentrations of each organ were analyzed. The species-specific and nonspecific changes in accumulation by the treatment were observed in different elements. Under phosphorus deficiency, sunflower showed a different variation in the ionome profile than the other species, particularly in the increased accumulation of many metal elements. Increased accumulation of many elements was observed in all plant species under potassium deficiency. Under nitrogen deficiency, leaf molybdenum accumulation was increased in non-leguminous plants. An unknown role of molybdenum in the metabolic responses to the nitrogen deficiency was predicted. To carry out further research based on the results of such ionomics studies may reveal the unknown function of essential elements in metabolic responses in plants. [ABSTRACT FROM AUTHOR]