Flavonoids are a group of secondary metabolites found in many higher plants. The multiple roles of their flavone subclass include protection against UV damage, regulation of auxin transport, and modulation of flower color. In soybean (Glycine max), flavone synthase II (FNS II) is the key enzyme responsible for flavone biosynthesis. Two FNS II genes from soybean cultivar Hefeng 47 were cloned according to basic local alignment search tool (BLAST) contexts using flavone synthase sequences reported in other species. These were named GmFNSII-1 and GmFNSII-2. Sequence alignments showed that the cDNA of GmFNSII-1 was identical to that of CYP93B16, whereas GmFNSII-2 was clearly distinct. Functional assays in yeast (Schizosaccharomyces pombe) suggested that these two enzymes could convert (2S)-naringenin into apigenin. The two GmFNSII genes had similar tissue-specific expression patterns, but GmFNSII-2 was significantly expressed in the roots after treatment with 0.4 M glucose. This demonstrates that the gene plays an important role in the response to defense signals in soybean. RNA interference-mediated suppression of those GmFNSII genes effectively regulated flavone and isoflavone production in hairy roots that arose from soybean cotyledons transformed with Agrobacterium rhizogenes (ATCC15834). Our study also highlights some of the challenges associated with metabolic engineering of plant natural products.

Domain IV nucleotides of human 7SL RNA comprise an approximately 50-nucleotide region with a highly conserved secondary structure consisting of two internal loops. We inserted these into a modified 3'-untranslated region of the human granulocyte-macrophage colony stimulating factor (hGM-CSF) gene. The expression vector, under the control of a tissue-specific promoter derived from the soybean ~' subunit of ~3-conglycinin, was introduced into Arabidopsis thaliana by Agrobacteriurn.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) transplantation is widely adopted for the curing of osteonecrosis of femoral head (ONFH) in recent years. Furthermore, it is known that introducing hepatocyte growth factor (HGF) into BM-MSCs will greatly improve the therapeutic effect of stem-cell therapy owing to the great angiogenic and anti-fibrotic capabilities of HGF. However, continuing overexpression of HGF in vivo may cause sarcomas, such as Kaposi's sarcoma. Aiming at enhancing the therapeutic effect and preventing the side effects of HGF-modified stem-cell transplantation on ONFH, we sought to construct a gene regulation system to control HGF expression in BM-MSCs rigorously and accurately. We selected baculovirus as the gene vector and introduced pTet-on advanced system into that. Finally, a virus vector vAc(rtTA2s-Ptight-HGF) was successfully built and delivered into BM-MSCs to regulate the accurate expression of HGF. As shown in the results, different levels of HGF expression were verified by ELISA and Western blot with different induction doses of doxycycline (DOX). There was a dose-response relationship between them, and the optimum dose of DOX to induce HGF expression in BM-MSCs in vitro was 1 µg/mL. We conclude that it is feasible to regulate HGF expression in BM-MSCs by baculovirus-mediated one-off transduction.

The human granulocyte-macrophage colony stimulating factor (hGM-CSF) containing either an endoplasmic reticulum (ER) retention signal or a phaseolin vacuolar sorting signal peptide was expressed in Arabidopsis thaliana under the control of a tissue-specific promoter, derived from the soybean α′ subunit of β-conglycinin. No significant differences in recombinant hGM-CSF (rhGM-CSF) accumulation were detected between transgenic plants carrying either one of the two signal peptides. Hybrid seed from crosses between single-copy transformants tailed with the ER retention signal tetrapeptide and single-copy transformed plants tagged with a phaseolin four carboxy-terminal residues showed gene additive effects. The highest expression level of rhGM-CSF was 0.05% of total soluble protein of immature siliques, indicating that the two signal peptides functioned independently in the protein-sorting pathway. Additionally, TF-1 cell proliferation data demonstrated that rhGM-CSF was biologically active.

The soybean aphid [Aphis glycines Matsumura (Hemiptera: Aphididae)] is an important pest insect of soybean [Glycine max (L.) Merr.] in China and North America. Identification of soybean aphid biotypes would facilitate more effective pest management. Although four soybean aphid biotypes have been discovered in North America to date, biotype determination has not been conducted in China. In this study, we analyzed the biotypes of soybean aphids collected from four different soybean‐growing areas in China in 2011. The responses of four soybean aphid isolates from Changchun (Jilin province), Jinan (Shandong province), and Shanghai and Guiyang (Guizhou province) were assessed by infesting 11 soybean genotypes in noncaged tests during 2 yr and infesting 7 genotypes in a caged test in 1 yr. We distinguished among the four isolates on the basis of their abilities to infest a set of host plants with the known resistance genes Rag1 through Rag6. The results showed that the biotype profiles of the four soybean aphid isolates were different from each other and that there are at least four biotypes of soybean aphid in China.