Agrobacterium-mediated transformation of the ß-subunit gene in 7S globulin protein in soybean using RNAi technology.

The objective of this study was to use RNA interference (RNAi) to improve protein quality and decrease anti-nutritional effects in soybean. Agrobacterium tumefaciens-mediated transformation was conducted using RNAi and an expression vector containing the 7S globulin ß-subunit gene. The BAR gene was used as the selective marker and cotyledonary nodes of soybean genotype Jinong 27 were chosen as explant material. Regenerated plants were detected by molecular biology techniques. Transformation of the ß-subunit gene in the 7S protein was detected by PCR, Southern blot, and q-PCR. Positive plants (10 T0, and 6 T1, and 13 T2) were tested by PCR. Hybridization bands were detected by Southern blot analysis in two of the T1 transgenic plants. RNAi expression vectors containing the soybean 7S protein ß-subunit gene were successfully integrated into the genome of transgenic plants. qRT-PCR analysis in soybean seeds showed a clear decrease in expression of the soybean ß-subunit gene. The level of 7S protein ß-subunit expression in transgenic plants decreased by 77.5% as compared to that of the wild-type plants. This study has established a basis for the application of RNAi to improve the anti-nutritional effects of soybean.

Analysis of quantitative trait loci for main plant traits in soybean.

Plant traits are important indices for regulating and controlling yield ability in soybean varieties. It is important to comprehensively study the quantitative trait locus (QTL) mapping for soybean plant traits, cloning related genes, and marker assistant breeding. In this study, 236 F2 generation plants and a derivative group were constructed by using Jiyu50 and Jinong18, obtained from Jilin Province. A total of 102 simple sequence repeat markers were used to construct a genetic linkage map. With 2 years of molecular and phenotypic data, QTL analyses and mapping were conducted for soybean maturity, plant height, main stem node, main stem branch, seed weight per plant, and more. Five main plant traits were analyzed via inclusive composite interval mapping using QTL IciMapping v2.2. Using one-dimensional scanning, a total of 30 QTLs were detected and distributed across 1 (A1), 4 (C2), and 12 (G). There were 9 linkage groups, including 16 major QTLs. Using two-dimensional scanning, 7 pairs of epistatic QTL interactions for maturity and plant height were detected in the soybean.

Identification of genes associated with the increased number of four-seed pods in soybean (Glycine max L.) using transcriptome analysis.

Seed number per pod is an important component of yield traits in soybean (Glycine max L.). In 2010, we identified a natural mutant with an increased number of four-seed pods from a soybean variety named 'Jinong 18' (JN18). Subsequent observations indicated that the trait was stably inherited. To identify and understand the function of genes associated with this mutant trait, we analyzed the genetic differences between the mutant (JN18MT01) and source variety (JN18) by transcriptome sequencing. Three types of tissues, axillary buds, unfertilized ovaries, and young pods at three different growth stages, V6, R1, and R3, were analyzed, respectively. The sequencing results yielded 55,582 expressed genes and 4183 differentially expressed genes (DEGs). Among these, the log2 ratio value of 162 DEGs was >10, and 13 DEGs had overlapping expression at three different growth stages. Comparisons of DEGs among three different growth stages yielded similar results in terms of the percentage of genes classified into each gene ontology (GO) category. DEGs were classified into 25 different functional groups in clusters of orthologous groups analysis. Proportions of the main functional genes differed significantly over developmental stages. A comparison of enriched pathways among the three developmental stages revealed that 646 unigenes were involved in 103 metabolic pathways. These results show that the development of four-seed pods is associated with a complex network involving multiple physiological and metabolic pathways. This study lays the foundation for further research on cloning and on the molecular regulation of genes related to the four-seed pod mutation.

Genetic analysis of the major gene plus polygene model in soybean resistance to Leguminivora glycinivorella.

In order to investigate the genetic characteristics of soybean Leguminivora glycinivorella resistance and to improve soybean resistance insectivorous breeding efficiency by applying the multi-generation joint analysis method of the major gene plus polygene model, 5 pedigrees and generations (P1, F1, P2, F2, and F2:3) were used as the materials to perform the soybean L. glycinivorella resistance multi-generation joint analysis. The results showed that soybean resistance to L. glycinivorella was controlled and inherited by an additive major gene plus additive, dominant polygene. The major gene had a negative additive effect (d = -0.1633). The combination of the anti-L. glycinivorella genes showed negative heterosis. Because the polygene additive effects were positive, the polygene effects would increase the insect herbivory rate in the F1 generation. This hybrid combination showed an insect herbivory rate polygenic heritability of 21.9556 and 54.3490% in the F2 and F2:3 pedigrees, which presented a high heritability. Therefore, it was appropriate to perform the selective breeding of the insect herbivory rate in the late generation.

Azithromycin enhances the favorable results of paclitaxel and cisplatin in patients with advanced non-small cell lung cancer.

Although new chemotherapeutic drugs have been applied constantly, their efficacy for non-small cell lung cancer (NSCLC) is still not satisfactory. In recent years, epidemiological investigations have shown that lung cancer may be induced by chronic Chlamydia pneumoniae (Cpn) infection, since stable high titers of Cpn antibodies, especially IgA, are a hallmark of chronic infections. Azithromycin is commonly used for the treatment of Cpn infections; however, there are only few reports regarding the application of azithromycin (A) combined with paclitaxel and cisplatin (TP) for advanced NSCLC. Considering that patients with NSCLC have a higher rate of Cpn infection, we proposed to employ azithromycin for Cpn infection in chemotherapy for advanced NSCLC. The aim of this study was to explore the effects of azithromycin on chemotherapy for NSCLC. A total of 86 patients with stage III-IV NSCLC were randomly divided into TP and ATP groups; the characteristics of patients in the two groups showed no significant differences. The TP group was treated with paclitaxel and cisplatin, and the ATP group was treated with azithromycin combined with TP for at least 4 weeks, followed by evaluation and comparison of efficacy, side effects and patients' quality of life before and after chemotherapy between the two groups. Testing for Cpn infection revealed a significant difference in the case number before and after therapy in the ATP group (P < 0.01) compared with the TP group (P > 0.05), and a statistical difference was observed (P < 0.01) between the ATP and TP groups after treatment. The changes in quality of life of patients after two different chemotherapy regimens were statistically significant (P < 0.05), but there was a significant difference in only cognitive function after treatment. The changes in symptom scores of patients after the two different chemotherapy regimens were statistically significant (P < 0.05), but there was a significant difference in only shortness of breath and cough after treatment. Kaplan-Meier estimate was utilized to describe the survival function of patients in the two groups. The median survival time was 12.0 months for the TP group and 13.0 months for the ATP group. One-year survival rates of the TP and ATP groups were 45.0 and 75.0%, respectively, which were significantly different (P < 0.05). Our study of azithromycin+paclitaxe l+cisplatin on stage III-IV NSCLC patients achieved favorable results in terms of side effects and overall survival.

Cloning and functional prediction of differentially expressed genes in the leaves of Glycine max parents and hybrids at the seedling stage.

Here, we compare the molecular mechanism of soybean heterosis through the differential expression of basic cloning. Specifically, we cloned 22 differentially expressed cDNA fragments from hybrid combinations of Jilin 38 x EXP (which had obvious yield advantages) and their parents. In addition, we compared the homology of these fragments and predicted their functions. Cloning differentially expressed genes included the identification of the calmodulin binding protein, 18S ribosomal gene, 26S ribosomal gene, soybean satellite DNA, soybean acid phosphatase, soybean chlorophyll a/b-binding protein II (Cab-6) gene, soybean chloroplast PI 437654 gene, soybean PPR protein gene, and other fragments with unknown functions. In conclusion, the cloning and functional prediction of differentially expressed soybean genes in this study is anticipated to provide valuable information for studies on the molecular mechanism of heterosis.

Problems with and a system to eliminate single-primer PCR product contamination in simple sequence repeat molecular marker-assisted selection in soybean.

Polymerase chain reaction (PCR) provides a foundation for simple sequence repeat molecular marker-assisted selection (SSR MAS) in soybean. This PCR system and its various conditions have been optimized by many researchers. However, current research on the optimization of the PCR system focuses on double-primer PCR products. We compared single- and double-SSR primer PCR products from 50 soybean samples and found that the use of single-PCR primers in the reaction system can lead to amplified fragments of portions of the SSR primers in the PCR process, resulting in both false-positives and fragment impurity of double-primer PCR amplification, inconvenient for subsequent analysis. We used "single-primer PCR correction" to eliminate interference caused by single-primer nonspecific PCR amplification and improve PCR quality. Using this method, the precision and success rates of SSR MAS in soybean can be increased.

Single-primer PCR correction: a strategy for false-positive exclusion.

Polymerase chain reaction (PCR) technology plays an important role in molecular biology research, but false-positive and nonspecific PCR amplification have plagued many researchers. Currently, research on the optimization of the PCR system focuses on double-primer-based PCR products. This research has shown that PCR amplification based on single-primer binding to the DNA template is an important contributing factor to obtaining false-positive results, fragment impurity, and nonspecific fragment amplification, when the PCR conditions are highly restricted during PCR-based target gene cloning, detection of transgenic plants, simple-sequence repeat marker-assisted selection, and mRNA differential display. Here, we compared single- and double-primer amplification and proposed "single-primer PCR correction"; improvements in PCR that eliminate interference caused by single-primer-based nonspecific PCR amplification were demonstrated and the precision and success rates of experiments were increased. Although for some kinds of experiments, the improvement effect of single-primer PCR correction was variable, the precision and success rate could be elevated at 12-50% in our experiment by this way.