Due to the very important effects of boron on root growth, it is expected to be effective on the absorption of nutrients (ions). Due to the reduced root growth, a decrease in the water uptake efficiency of the plants may also occur.
In addition to these general effects, it is known that boron nutrition specifically reduces the intake of some elements. For example, Boron strongly affects the membrane-dependent ATPase enzyme activity, which has an important role in the ion uptake of plants. This enzyme significantly affects the ion uptake, especially potassium and phosphorus uptake of the roots from the nutritional medium. It is known that decreases in potassium uptake occur in plants under boron deficiency due to its reducing effects on ATPase enzyme activity. There are research findings showing that ATPase enzyme activity is dramatically affected by very short-term Boron applications (for example, within minutes) in physiological trials with model plants and plant cell cultures. Boron is presumed to possibly have direct effects on the structural and/or functional integrity of the enzyme.
According to the findings in the literature, plants under boron deficiency have less potassium than plants with good boron nutrition. This observation indicates that plants actually take less potassium from the environment under boron deficiency conditions. In addition, there are research results showing that the Potassium taken from the environment by the roots is then given back to the nutrition medium from the roots with the emergence of Boron deficiency in the plant. It is estimated that the increased amount of potassium outflow from the roots (efflux) occurs as a result of the membranes losing their stability due to Boron deficiency and therefore increasing their permeability.
In the project carried out between BOREN and Sabancı University, it was found that plants with Boron deficiency receive less Potassium and Phosphorus from the nutritional medium than plants with good boron nutrition. These results point out that even if there is high amount of Potassium in the environment, the plants must have a good Boron nutritional status in order for Potassium to be taken up and used by plants at a sufficient level.
There is a synergistic relationship between Potassium and Nitrate in plants, both during absorption by the roots and during transport from the roots to the green parts. In other words, as the potassium intake of the plants increases, there is a general increase in the nitrate intake from the environment. Consistent with this information, it has been found that the reductions in Potassium uptake under boron deficiency conditions adversely affect the Nitrate (Nitrogen) uptake of the roots. The results show that a good Boron nutrition has an indispensable importance for the efficiency of nutrient utilization of plants, especially Potassium and Nitrogen.