Journal of Soil and Plant Interactions

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To date, limited research has been done worldwide on uptake and translocation of nanoparticles (NPs) by plants. To evaluate such processes, soybean (Glycine max L.) was cultured in modified Hoagland nutrient solution containing Fe3O4 NPs with concentration of 60 mg/L, and 33 mg/L iron chelate (Fe-EDTA) was taken as control. After 28 days, the strength of magnetic signal was measured in different organs of the soybean by vibrating sample magnetometer (VSM) instrument. Result showed no magnetization signal from the control plants, but signals with various strengths were found in the tissue samples of the treated plants. Strong magnetic signal in soybean leaves clearly indicated the uptake and translocation of Fe3O4 NPs by roots and xylem. The strongest magnetic signal (138 memu/g) was detected in roots, and transfer coefficient of NPs from roots to leaves was about 0.9 percent. Exudates and surface charge of roots caused accumulation of magnetite NPs on soybean roots' surface. A small fraction of particles moved through simplastic pathways into the xylem and streamed to leaves via sap flow. NPs were accumulated in the crown more than other aerial parts, due to vascular change in structure (root to shoot). In summary, results demonstrated that Fe3O4 NPs can be taken up by soybean and be translocated to other plant tissues in molecular form

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Recently, attentions have been taken on the investigations regarding the use of nano-sized compounds in different fields including agricultural sector. Due to the importance of evaluating the fate and operation of nano-particles in plant systems, in this survey, responses of 13 wheat genotypes to the effect of nano-iron chelate fertilizer in the Hoagland solution under the conditions of ordinary iron chelate and nano-iron chelate, with concentration of 22.5 mg/L, was studied. This experiment was carried out in Research Greenhouse of Soilless Culture Research Center, Isfahan University of Technology, Iran, in the spring of 2013. Results showed that there were considerable positive and negative variations among wheat genotypes in response to application of nano-sized iron chelate fertilizer. Under the application of iron chelate, among the different measured traits, number of tillers and root/shoot ratio had the highest coefficient of variations, and the lowest values were observed for chlorophyll flourescence and green leaf surface. Under the application of nano-iron chelate, number of tillers and root/shoot ratio had the highest coefficient of variations, and the lowest value was observed for chlorophyll flourescence content. Nano-iron chelate fertilizer caused reduction of average dry matter yield of shoots, leaf area and root volume by 14.1, 9.5 and 8.9 percent, respectively, and increased root/shoot ratio by 13.7% for some wheat varieties, in comparison with the ordinary iron chelate. In response to nano-iron chelate fertilizer, compared to ordinary iron chelate, Line-9-shoory produced the highest total dry matter (14.49% increase) and Star variety had the lowest total dry matter (-51.82%).

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In order to determine the best source of iron fertilizer for green pepper under alkaline conditions, the experiment was conducted as factorial with three factors include of iron fertilizer (control, Fe-EDDHA and nano iron chelate), sodium bicarbonate (0 and 10 mM) and two cultivars (Bonanza and Griffaton) with three replications. Plants were treated with bicarbonate 45 days after planting for 2 month. The results indicated that the maximum vegetative parameters (root and shoot fresh and dry weight), reproductive parameters (number of fruits, fruit length, fruit weight and fruit diameter) and physiological paramneters (RWC, PI and F_v/F_m) were found in control treatment. Under the alkaline condition maximum and the minimum chlorophyll a and b and carotenoid contents were obtained in control and Fe-EDDHA treatment, respectively. Sodium bicarbonate significantly decreased the Fe concentration in root and shoot of pepper. According the results obtained from this work, Fe-EDDHA was the best iron fertilizer under the alkaline conditions and nano chelate iron was next in this situation.