Production and characterization of transgenic maize plants designed to improve iron nutrition

Abstract

The increasing need to find alternative solutions to the devastating effects of iron deficiency anemia has led to the generation of crops with improved nutritional quality traits. Iron is one of the required but limited mineral elements in most diets consumed by people in developing countries who have limited access to supplements or iron-rich diets. With much of the world's population dependent on maize as a major source of their daily calorie intake, research toward improving its nutritional value is deemed necessary. The major objective of this research was to produce and characterize transgenic maize lines with improved iron content. To do this, two studies were carried out. In the first study, maize seed endosperms expressing the soybean ferritin (SoyFer1, GenBank accession number M64337) and the E. coli phytase (appA, Genbank accession number L03375) transgenes, individually and in combination, were produced by stable genetic transformation using particle bombardment. The endosperm-specific super gamma zein promoter was used to drive transgene expression. Transgene presence was confirmed by polymerase chain reaction (PCR), while transgene expression was confirmed in seed samples by western blot analysis. The activity of the phytase enzyme was determined using enzyme bioassays specific for the phytase. The PCR analyses results confirmed the presence of the soybean ferritin and E. coli phytase transgene DNA, implying successful integration into the maize genome. Protein analysis results further confirmed the expression of the transgenes in the maize seed endosperms. The highest phytase enzyme activity obtained from maize seeds

Itinerant-localized dual character of a strongly correlated superfluid Bose gas in an optical lattice

“…Extending the standard basis operator method developed by Haley and Erdös [15] to the boson Hubbard model, we calculate the superfluid density of states at T = 0. This method has been recently used by Sheshadri [7], Kanobe [16] and their coworkers to study the SI transition and the rf-spectrum in the Mott phase, respectively. In the superfluid phase near the SI transition, we show the coexistence of the itinerant gapless Bogoliubov mode and a band with a finite threshold energy, which reflects the localized character of atomic states.…”

“…∆E n−1,n may be regarded as the energy to add a hole to the ground state. The SI transition is determined by the condition when (8) has a gapless excitation at p = 0, which gives [3,7,9,16] The lowest value of U/zt to realize the Mott phase equals U/zt = 3 + 2 √ 2 = 5.83 (n = 1) [1,7,9]. We show the SI phase boundary given by (10) in Fig.…”

“…2. Because of the step function in (13), the second term is dominated by hole excitations at T = 0 [16]. Figure 4 shows the rf-spectrum near the Mott phase with n = 1.…”