Soybean proteins are widely used for human and animal feeds worldwide. The use of soybean protein has been expanded in the food industry due to their excellent nutritional benefits. But, antinutritional and allergenic factors are present in the raw mature soybean. P34 protein, referred as Gly m Bd 30K, has been identified as a predominant immunodominant allergen. The objective of this research is to identify the genetic mode of P34 protein for the improvement of soybean cultivar with a very low level of P34 protein. Two F2 populations were developed from the cross of "Pungsannamulkong" x PI567476 and "Gaechuck2ho" x PI567476 (very low level of P34 protein). Relative amount of P34 protein was observed by Western blot analysis. The observed data for the progeny of "Pungsannamulkong" and PI567476 were 133 seeds with normal content of P34 protein and 35 seeds with very low level of P34 protein (X2=1.157, P=0.20-0.30). For the progeny of "Gaechuck#1" and PI567476, the observed data were 177 seeds with normal content of P34 protein and 73 seeds with very low level of P34 protein (X2=2.353, P=0.10-0.20). From pooled data, observed data were 310 seeds with normal content of P34 protein and 108 seeds with very low level of P34 protein (X2=0.156, P=0.50-0.70). The segregation ratio (3:1) and the Chi-square value obtained from the two populations suggested that P34 protein in mature soybean seed is controlled by a single major gene. Single gene inheritance of P34 protein was confirmed in 32 F2 derived lines in F3 seeds, which were germinated from the low level of P34 protein obtained from the cross of "Pungsannamulkong" and PI567476. These results may provide valuable information to breed for new soybean line with low level of P34 protein and identification of molecular markers linked to P34 locus.
Transient expression profiles for several chimeric β-glucuronidase (GUS) gene constructs were determined in microspore-derived embryos of wheat following microprojectile bombardment. The constructs analyzed consisted of the uidA (GUS) reporter gene driven by six different promoters [Cauliflower Mosaic Virus 35S (CaMV35S), Nopaline synthase (NOS), Mannopine synthase (MAS), Chlorella Mosaic Virus Adenin methyltransferase (AMT), maize Ubiquitin 1 (UBI1), and enhanced 35S (E35S)]. The total numbers of GUS blue spot were determined manually under a dissecting microscope after histochemical staining for GUS. Results suggest that the E35S promoter is the most active and UBI1 promoter is the second active in embryos or embryogenic calli derived from wheat microspore. In addition, by flurometric assay on GUS, the E35S promoter was the best. Therefore, both UBI1 and E35S promoter are suitable for constitutive expression of the gene of interest in microspore-derived embryos of wheat. This information describing promoter functionality in wheat will be important when designing gene constructs for traits modification and when choosing appropriate cultivars for improvement through gene transfer experiments.
The effect of osmotic condition on β-glucuronidase (GUS) transient expression was evaluated in microspore-derived embryos of wheat. Microspore explants were treated on medium containing various mannitol concentrations prior to and post bombardment with plasmid DNA pAHC25 containing uidA gene controlled by maize ubiquitin 1 (UBI1) promoter. GUS expression in the bombarded explants was examined by histochemical and fluorometric assays. Increased GUS expression was observed with mannitol treatment when compared to untreated explants. The histochemical study showed that the number of blue (GUS) foci were the highest in the bombarded explants treated with 0.6 M mannitol medium. The fluorometric assay of bombarded explants also proved 3.5-fold increase in GUS activity with 0.6 M mannitol treatment when compared to without mannitol treatment. These results indicate that 0.6 M mannitol is beneficial for improving transformation efficiency of wheat microspore-derived embryos or embryogenic calli through biolistic transformation.
Transformed cassava plants were successfully produced from friable embryogenic calli derived from leaf lobes byAgrobacterium tumefaciens-mediated transformation. We used A. twnefaciens strain LBA4404 containing pCAMmPHY whichcontained a binary vector with
Characteristics related to grain quality and starch viscosity were investigated in three independent japonica transgenicrice lines expressing a Protox gene from Bacillus subtilis and compared to the control. In this study, we found that there were nosigni
apical meristem using Agrobacterium tumefaciens-mediated transformation method. The plant expression vector used in the studycontained GUS gene and NPTI for selection under the control of CaMV35S promoter. Transformed calli and plantlets wereselected on G