The purpose of this study is to explore one bilingual person’s language development in relation to the changing environments in which she has lived. Bronfenbrenner's (1977, 1979, 1992) bioecological model provided insight as a theoretical framework in that the model emphasizes active interactions and strong interconnectedness between the individual and her surrounding environments, as well as interactions among environments (micro, meso, exo, and macrosystem). As a main data source, a two and half hour semi-structured interview was conducted with the participant, who is a Korean-English bilingual pursuing a graduate degree at an American university. The analysis of the interview data revealed that 1) the participant's developing characteristics (e.g., outgoing personality, age of language learning), 2) the changing environments (e.g., parents’ belief and philosophy, home residential location), and 3) the interactions between the participant and her environments (e.g., the participant’s intrinsic motivation and the mother’s philosophy) and interactions between inner and outer environments (e.g., school system and national educational policy) played out for the participant's reach on the current language development in Korean and English.

The plant-specific NAC (NAM, ATAF, and CUC)-domain proteins play important roles in plant development and stress responses. Comparative time-course expression analyses were carried out to analyze the expression levels of 62 soybean NAC genes during drought stress in order to search for the stress-inducible NAC genes. Ten GmSNAC (Glycine max stress-inducible NAC) genes having the significant differential expression in response to the drought stress and abscisic acid (ABA) hormone application were further investigated for their expression profiles with various stresses such as drought, high salinity, cold and with ABA treatments by the quantitative real-time PCR analyses. In this research, the full-length cDNAs of eight GmSNAC were isolated for the further studies. Eight GmSNAC proteins were tested for their transcription activation in the yeast assay system. Two GmSNAC proteins showed the very high transcriptional activities and the other two GmSNAC proteins displayed moderate levels of transactivation while the remaining four GmSNAC proteins lacked transactivation in yeast. Subcellular localization of eight GmSNAC proteins was analyzed via the green fluorescent protein-GmSNAC fusion protein in tobacco plant cell. Three GmSNAC proteins with the C-terminal transmembrane domain were localized to the nucleus and cytoplasmic fractions. The other five GmSNAC proteins were targeted to the nucleus. The function of GmSNAC49 gene was further investigated using the overexpression transgenic Arabidopsis. Germination rate in transgenic plants over-expressing GmSNAC49 was delayed in the media supplemented with mannitol or ABA compared with that of wild-type (WT) plants. The 35S:GmSNAC49 transgenic Arabidopsis displayed improved tolerance to drought stress compared to the WT. The results of this systematic analysis of the GmSNAC family responsive to abiotic stress will provide novel tools and resources for the development of improved drought tolerant transgenic soybean cultivars

The ubiquitin conjugating enzyme E2 (UBC E2) mediates selective ubiquitination, acting with E1 and E3 enzymes to designate specific proteins for subsequent degradation. In the present study, we characterized the function of the mung bean VrUBC1 gene (Vigna radiata UBC 1). RNA gel-blot analysis showed that VrUBC1 mRNA expression was induced by either dehydration, high salinity or by the exogenous abscisic acid (ABA), but not by low temperature or wounding. Biochemical studies of VrUBC1 recombinant protein and complementation of yeast ubc4/5 by VrUBC1 revealed that VrUBC1 encodes a functional UBC E2. To understand the function of this gene in development and plant responses to osmotic stresses, we overexpressed VrUBC1 in Arabidopsis (Arabidopsis thaliana). The VrUBC1-overexpressing plants displayed highly sensitive responses to ABA and osmotic stress during germination, enhanced ABA- or salt-induced stomatal closing, and increased drought stress tolerance. The expression levels of a number of key ABA signaling genes were increased in VrUBC1-overexpressing plants compared to the wild-type plants. Yeast two-hybrid and bimolecular fluorescence complementation demonstrated that VrUBC1 interacts with AtVBP1 (A. thaliana VrUBC1 Binding Partner 1), a C3HC4-type RING E3 ligase. Overall, these results demonstrate that VrUBC1 plays a positive role in osmotic stress tolerance through transcriptional regulation of ABA-related genes and possibly through interaction with a novel RING E3 ligase.

Heat shock transcription factors (HSFs) are the major heat shock factors regulating the heat stress response. They participate in regulating the expression of heat shock proteins (HSPs), which are critical in the protection against stress damage and many other important biological processes. In this study, a genome-wide analysis was carried out to identify all HSFs soybean genes. Twenty six nonredundant HSF genes (GmHsf) were identified in the latest soybean genome sequence. Chromosomal location, protein domain and motif organization of GmHsfs were analyzed in soybean genome. The phylogenetic relationships, gene duplications and expression profiles of GmHsf genes were also presented in this study. According to their structural features, the predicted members were divided into the previously defined classes A–C, as described in Arabidopsis. Using RT-PCR, the expression patterns of 26 GmHsf genes were investigated under heat stress. The data revealed that these genes presented different expression levels in response to heat stress conditions. Real-time (q)RT-PCR was performed to investigate transcript levels of five GmHsfs in response to multiple abiotic stresses. Differential expression of five GmHsfs implies their role during abiotic stresses. Subcellular localization using GFP-fusion protein demonstrated that GmHsf12 and GmHsf34 were restricted to the nucleus and GmHsf28 was localized in the nucleus and cytoplasm in plant. The results provide a fundamental clue for understanding of the complexity of the soybean HSF gene family and cloning specific function genes in further studies and applications.

A low temperature-inducible cDNA designated as VrUBC1 from mungbean (Vigna radiata) was isolated by subtractive hybridization method. By rapid amplification of cDNA end technique, the full-length cDNA of VrUBC1 was obtained. The full-length cDNA of VrUBC1 contains an open reading frame of 444 nucleotides in length and capable of specifying a 16.5-kDa protein of 148 amino acids (aa) with an isoelectric point of 7.72. VrUBC1 mRNA was induced by NaCl and ABA, but not by wounding and low temperature stress. It was shown that VrUBC1-GFP was localized to the cytoplasm in tobacco cell. To examine the function of VrUBC1, VrUBC1 was expressed in Escherichia coli as His-fusion protein. Purified VrUBC1-His recombinant protein was shown to have ubiquitination activity in vitro. For the in vivo functional analysis of VrUBC1, VrUBC1 was expressed in yeast ubc4/5 double mutant. Stress tolerance was tested in the VrUBC1 overexpressing Arabidopsis transgenic plants. We propose that VrUBC1 play an important role in protein degradation processes during abiotic stress in plants.

Photorespiration reduces carbon fixation rate, but is essential process in plant. Photorespiration involves reactions in chloroplasts, peroxisomes, and mitochondria. In photorepiratory peroxisome, alanine glyoxylate aminotransferase (AGT) catalyzes alanine and glyoxylate into glycine and pyruvate. We isolated a low temperature-inducible cDNA encoding AGT from mungbean leaves. The full-length cDNA, designated as MLT9, contains an open reading frame of 1,203 nucleotides coding for a protein of 401 amino acids. Genomic DNA blotting showed that the mungbean genome has one copy of MLT9. MLT9 mRNA was induced not only by low temperature but also by drought stress, but ABA and NaCl did not induce RNA expression of MLT9. In mungbean, AGT activity was higher in the non-stressed leaves compared to the low-temperature treated leaves. Based on GFP/RFP targeting experiment, GFP-MLT9 fusion protein and SKL-RFP, a peroxisome marker, were colocalized to peroxisome in tobacco protoplasts. This suggests that peroxisomal MLT9 plays a role in photorespiratory metabolism in response to low temperature and drought stress.