Effect of soil salinity on the growth, amino acids and ion contents of rice transgenic lines

Rice seedling of different transgenic lines (T-99, T-112, T-115 and T-121) were grown in sand culture with salt concentration of 0, 50, 100 and 150 mM to determine the effect of salinity on growth, amino acid, and ion contents. It was observed that all the lines could tolerate concentration of up to 50 mM of salt solution. The lines (T-99, T-112 and T-115) were more salt tolerant even at a concentration of 100 mM of NaCl with their relative growth rate (RGR), and net assimilation rate (NAR) were unaffected as compared to the control. With the increase in salt concentrations, the proline contents increased for all the transgenic lines. On the other hand, a gradual decrease in the contents of glycine and arginine were observed with the increase in salinity treatments. A massive increase in the Na+ contents was measured in all the transgenic lines by application of the saline solutions. The K+ and Ca++ contents decreased with the increase in salt concentrations. The present study shows that although the plants accumulated Na, the lines T-99, T-112 and T-115 could tolerate concentrations of up to 100 mM.Key words: Salt stress, proline, glycine, Na, K, Ca, Oryza sativa

Stimuli-Responsive Drug Delivery of Doxorubicin Using Magnetic Nanoparticle Conjugated Poly(ethylene glycol)-<i>g</i>-Chitosan Copolymer

Stimuli-responsive nanoparticles are regarded as an ideal candidate for anticancer drug targeting. We synthesized glutathione (GSH) and magnetic-sensitive nanocomposites for a dual-targeting strategy. To achieve this goal, methoxy poly (ethylene glycol) (MePEG) was grafted to water-soluble chitosan (abbreviated as ChitoPEG). Then doxorubicin (DOX) was conjugated to the backbone of chitosan via disulfide linkage. Iron oxide (IO) magnetic nanoparticles were also conjugated to the backbone of chitosan to provide magnetic sensitivity. In morphological observation, images from a transmission electron microscope (TEM) showed that IO nanoparticles were embedded in the ChitoPEG/DOX/IO nanocomposites. In a drug release study, GSH addition accelerated DOX release rate from nanocomposites, indicating that nanocomposites have redox-responsiveness. Furthermore, external magnetic stimulus concentrated nanocomposites in the magnetic field and then provided efficient internalization of nanocomposites into cancer cells in cell culture experiments. In an animal study with CT26 cell-bearing mice, nanocomposites showed superior magnetic sensitivity and then preferentially targeted tumor tissues in the field of external magnetic stimulus. Nanocomposites composed of ChitoPEG/DOX/IO nanoparticle conjugates have excellent anticancer drug targeting properties

Follow-up of Shelhigh porcine pulmonic valve conduits

BACKGROUND: We implanted Shelhigh porcine pulmonic valve conduits because of the limited availability of homografts in our country. The aim of this study was to evaluate the short-term results of SPVC. METHODS: From November 2002 to July 2005, the Shelhigh porcine pulmonic valve conduit was implanted in 73 patients (81 procedures) in the right ventricular outflow tract to correct congenital heart diseases. Operative procedures were Rastelli operation in 65, anatomic correction of atrioventricular discordance in 5, and Ross operation in 3. Age at operation was 6.8 +/- 7.5 years, including 11 patients under 1 year. The median conduit size was 18 mm (range, 12 to 24 mm). RESULTS: There was no operative mortality and 1 nonconduit-related late death (mean follow-up, 11.3 +/- 10.7 months). Ten conduits (12.3%, 7 patients) were removed at a median of 9.6 months (range, 2.5 to 25.4) owing to obstruction in 9 and pseudoaneurysm in 1. In the explanted conduits, we found a prominent intimal peel at the distal anastomosis without leaflet calcification. Freedom from reoperation at 24 months was 87% +/- 11.7% in large-sized conduits (>or=18 mm) and 62.8% +/- 10.6% in small-sized conduits (or=18 mm) fail after 2 years of implantation due to intimal peel formation at the distal segment

Construction of Soybean Mutant Diversity Pool (MDP) Lines and an Analysis of Their Genetic Relationships and Associations Using TRAP Markers

Mutation breeding is useful for improving agronomic characteristics of various crops. In this study, we conducted a genetic diversity and association analysis of soybean mutants to assess elite mutant lines. On the basis of phenotypic traits, we chose 208 soybean mutants as a mutant diversity pool (MDP). We then investigated the genetic diversity and inter-relationships of these MDP lines using target region amplification polymorphism (TRAP) markers. Among the different TRAP primer combinations, polymorphism levels and polymorphism information content (PIC) values averaged 59.71% and 0.15, respectively. Dendrogram and population structure analyses divided the MDP lines into four major groups. According to an analysis of molecular variance (AMOVA), the percentage of inter-population variation among mutants was 11.320 (20.6%), whereas mutant intra-population variation ranged from 0.231 (0.4%) to 14.324 (26.1%). Overall, intra-population genetic similarity was higher than that of inter-populations. In an analysis of the association between TRAP markers and agronomic traits using three different statistical approaches based on the single factor analysis (SFA), the Q general linear model (GLM), and the mixed linear model (Q+K MLM), we detected six significant marker&ndash;trait associations involving five phenotypic traits. Our results suggest that the MDP has great potential for soybean genetic resources and that TRAP markers are useful for the selection of soybean mutants for soybean mutation breeding

Genome-Wide Association Study (GWAS) of the Agronomic Traits and Phenolic Content in Sorghum (<i>Sorghum bicolor</i> L.) Genotypes

Sorghum (Sorghum bicolor L.) is a promising biomass crop with high yields of cellulose, hemicellulose, and lignin. Sorghum biomass has emerged as an eco-friendly industrial material useful for producing biofuels and bioplastics. This study conducted genotyping-by-sequencing (GBS)-based genome-wide association studies (GWAS) to establish the genetic basis of traits associated with biomass. Specifically, the researchers evaluated agronomic traits and phenolic compounds using 96 sorghum genotypes. Six phenolic compounds, luteolinidin diglucoside, luteolin glucoside, apigeninidin glucoside, luteolinidin, apigeninidin, and 5-O-Me luteolinidin, were found to be the major phenolic compounds in all genotypes. Out of our six detected phenolic compounds (luteolinidin diglucoside, luteolin glucoside, apigeninidin glucoside, luteolinidin, apigeninidin, and 5-O-Me luteolinidin), luteolinidin was the major phenolic compound in all genotypes. Next, a GWAS analysis was performed to confirm significant associations between 192,040 filtered single-nucleotide polymorphisms (SNPs) and biomass-related traits. The study identified 40 SNPs on 10 chromosomes that were significantly associated with heading date (4 SNPs), plant height (3 SNPs), dry yield (2 SNPs), and phenolic compounds (31 SNPs). The GWAS analysis showed that SbRio.10G099600 (FUT1) was associated with heading date, SbRio.09G149200 with plant height, SbRio.06G211400 (MAFB) with dry yield, SbRio.04G259800 (PDHA1) with total phenolic content and luteolinidin diglucoside, and SbRio.02G343600 (LeETR4) with total phenolic content and luteolinidin, suggesting that these genes could play key roles in sorghum. These findings demonstrate the potential value of sorghum as a biomass resource and the potential for selecting sorghum genotypes with reduced phenolic contents for use in the bioindustry

Identification of Loci Governing Agronomic Traits and Mutation Hotspots via a GBS-Based Genome-Wide Association Study in a Soybean Mutant Diversity Pool

In this study, we performed a genotyping-by-sequencing analysis and a genome-wide association study of a soybean mutant diversity pool previously constructed by gamma irradiation. A GWAS was conducted to detect significant associations between 37,249 SNPs, 11 agronomic traits, and 6 phytochemical traits. In the merged data set, 66 SNPs on 13 chromosomes were highly associated (FDR p &lt; 0.05) with the following 4 agronomic traits: days of flowering (33 SNPs), flower color (16 SNPs), node number (6 SNPs), and seed coat color (11 SNPs). These results are consistent with the findings of earlier studies on other genetic features (e.g., natural accessions and recombinant inbred lines). Therefore, our observations suggest that the genomic changes in the mutants generated by gamma irradiation occurred at the same loci as the mutations in the natural soybean population. These findings are indicative of the existence of mutation hotspots, or the acceleration of genome evolution in response to high doses of radiation. Moreover, this study demonstrated that the integration of GBS and GWAS to investigate a mutant population derived from gamma irradiation is suitable for dissecting the molecular basis of complex traits in soybeans