Genome-Wide Association Mapping of Mixed Linkage (1,3;1,4)-beta-Glucan and Starch Contents in Rice Whole Grain

The glucan content of rice is a key factor defining its nutritional and economic value. Starch and its derivatives have many industrial applications such as in fuel and material production. Non-starch glucans such as (1,3;1,4)-beta-D-glucan (mixed-linkage beta-glucan, MLG) have many benefits in human health, including lowering cholesterol, boosting the immune system, and modulating the gut microbiome. In this study, the genetic variability of MLG and starch contents were analyzed in rice (Oryza sativa L.) whole grain, by performing a new quantitative analysis of the polysaccharide content of rice grains. The 197 rice accessions investigated had an average MLG content of 252 mu g/mg, which was negatively correlated with the grain starch content. A new genome-wide association study revealed seven significant quantitative trait loci (QTLs) associated with the MLG content and two QTLs associated with the starch content in rice whole grain. Novel genes associated with the MLG content were a hexose transporter and anthocyanidin 5,3-O-glucosyltransferase. Also, the novel gene associated with the starch content was a nodulin-like domain. The data pave the way for a better understanding of the genes involved in determining both MLG and starch contents in rice grains and should facilitate future plant breeding programs

Genome-wide association study for lignocellulosic compounds and fermentable sugar in rice straw

Cellulose and lignin are the two main components of secondary plant cell walls with substantial impact on stalk in the field and on straw during industrial processing. The amount of fermentable sugar that can be accessed is another important parameter affecting various industrial applications. In the present study, genetic variability of rice (Oryza sativa L.) genotypes for cellulose, lignin, and fermentable sugars contents was analyzed in rice straw. A genome-wide association study of 33,484 single nucleotide polymorphisms (SNPs) with a minor allele frequency (MAF) >0.05 was performed. The genome-wide association study identified seven, three, and three genomic regions to be significantly associated with cellulose, lignin, and fermentable sugar contents, respectively. Candidate genes in the associated genomic regions were enzymes mainly involved in cell wall metabolism. Novel SNP markers associated with cellulose were tagged to GH16, peroxidase, GT6, GT8, and CSLD2. For lignin content, Villin protein, OsWAK1/50/52/53, and GH16 were identified. For fermentable sugar content, UTP-glucose-1-phosphate uridylyltransferase, BRASSINOSTEROID INSENSITIVE 1, and receptor-like protein kinase 5 were found. The results of this study should improve our understanding of the genetic basis of the factors that might be involved in biosynthesis, turnover, and modification of major cell wall components and saccharides in rice straw

Genetic Variation in Response to Global Warming in a Coral Reef Species, Porites lobata

Climate change due to global warming is one of the worst environmental disasters in the world, which affects all ecosystems and has led to increasing degradation of coral reefs. The increase of sea surface temperature is inversely related to the resistance of corals and is directly associated with their bleaching. High temperature disrupts the symbiotic relationship between coral and algal symbiont and results in coral bleaching. To evaluate the adaptation of corals to heat stress, in this study, we investigated the thermal stress effect on the expression of genes involved in programmed cell death (PCD), cysteinyl aspartate proteases 3 (will be mentioned as Caspas3 hereafter) and anti-apoptotic pathway, B-cell lymphoma 2 (will be mentioned as Bcl2 hereafter) in Porites lobata (Dana, 1846). Corals were incubated at 25°C for 2 weeks (adaptation period) and then exposed to 34°C (heat shock) for 24 and 48 hours. Then, the expression of genes was measured using real-time PCR. The results revealed that both genes were up-regulated at 24 hours after heat induction. Bcl-2 expression (anti-apoptotic gene) was induced at 24 hours and was down-regulated at 48 hours. In contrast, Caspase3 (apoptotic gene) continued to be expressed up to 48 hours. These results might indicate that coral cells are headed towards bleaching and death with increased temperature. The results of this study, regarding the observed expression patterns, can clarify the response of different genes to a thermal stress in coral reefs. The exposure of corals to acute conditions with high temperatures presented the behavior of the desired genes in the studied conditions

Functional analysis of cell wall-related barley glycosyltransferases/ Naser Farrokhi.

"June 2005"Bibliography: pages 325-365.xviii, 365 pages : ill. (col.), plates (col.), photographs (col.) ; 30 cm.Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Plant and Pest Science, 200

Effect of Reversible Inactivation of the Kolliker Fuse Nucleus on Basal Blood Pressure and Heart Rate in Anesthetized Rat

Introduction: Several supra spinal areas such as rostral ventrolateral medulla (RVLM) area are involved in basic cardiovascular regulation. The Kolliker— Fuse nucleus (KF) is located in pons and is heavily connected with RVLM. The cardiovascular effect of KF nucleus has been shown and it is suggested that KF is involved in sympathetic vasomotor tone and basic cardiovascular regulation. Therefore, in the present study, the effects of KF on basic cardiovascular values were evaluated. Materials & Methods: After induction of anesthesia, a polyethylene catheter (PE-50) filled with heparinized saline was inserted into the femoral artery of rats. Animals were then placed in a stereotaxic apparatus and KF nucleus was inactivated by microinjection of cobalt chloride (CoCl2). Blood pressure and heart rate (HR) were continuously recorded pre and post inactivation. Results: Our result showed that inactivation of KF slightly changed mean arterial blood pressure (MAP) (92.3 ± 2.45 mmHg vs. 90.86 ± 1.7 mmHg) and HR (343.8 ± 4.6 beats/min vs. 350.7 ± 8.32 beats /min). However, these effects were not significant in comparison to the control group. Discussion: We concluded that synapses in the KF nucleus have no effect on regulation of basal blood pressure and heart rate, because CoCl2 is a synaptic blocker

Sequential path analysis of some yield and quality components in sugar beet grown in normal and drought conditions

Through biometrical analyses of yield and its components selection indices can be generated and be used in future breeding programs. Sugar yield components were considered as the first order variables (FOV) in previous path analyses studies, while white sugar yield (WSY) and its related traits were the FOV here. Three lines of sugar beet (7219-P.69, BP-Karaj, 7112) were evaluated in drought and non-drought conditions. Two sequential path models were used for analysis of associations among WSY and its related traits by arraying the various variables in first-, second-, and third-order paths on the basis of their maximum direct effects and minimal collinearity. Four first-order variables, namely root diameter, sugar yield, molasses content and sugar content, revealed highest direct effects on WSY at normal condition, while root length, α-amino-N, root yield, crown dry weight, water use efficiency and Na+ were found to fit as second-order variables. Three first-order variables, namely sugar content, sugar yield and molasses content, revealed highest direct effects on white sugar yield at drought-stress condition. In this case, sugar yield had the highest direct effect on WSY. In general, the sequential path analysis was efficiently demonstrated the effects of predictor variables

Cohnella amylopullulanases: Biochemical characterization of two recombinant thermophilic enzymes.

Some industries require newer, more efficient recombinant enzymes to accelerate their ongoing biochemical reactions in harsh environments with less replenishment. Thus, the search for native enzymes from extremophiles that are suitable for use under industrial conditions is a permanent challenge for R & D departments. Here and toward such discoveries, two sequences homologous to amylopullulanases (EC 3.2.1.41, GH57) from an endogenous Cohnella sp., [Coh00831 (KP335161; 1998 bp) and Coh01133 (KP335160: 3678 bp)] were identified. The genes were heterologously expressed in E. coli to both determine their type and further characterize their properties. The isolated DNA was PCR amplified with gene specific primers and cloned in pET28a, and the recombinant proteins were expressed in E. coli BL21 (DE3). The temperatures and pH optima of purified recombinants Coh 01133 and Coh 00831 enzymes were 70°C and 8, and 60°C and 6, respectively. These enzymes are stable more than 90% in 60°C and 50°C for 90 min respectively. The major reactions released sugars which could be fractionated by HPLC analysis, from soluble starch were mainly maltose (G2), maltotriose (G3) and maltotetraose (G4). The enzymes hydrolyzed pullulan to maltotriose (G3) only. Enzyme activities for both proteins were improved in the availability of Mn2+, Ba2+, Ca2+, and Mg2+ and reduced in the presence of Fe2+, Li2+, Na2+, Triton X100 and urea. Moreover, Co2+, K+, and Cu2+ had a negative effect only on Coh 01133 enzyme

Transcript Analysis of Heat Shock Protein 72 in Vitrified 2-Cell Mouse Embryos and Subsequent In Vitro Development

Objective: The aim of the study was to compare the effects of two different concentrations of cryoprotectants by cryotopvitrification on survival, developmental capacity and Heat shock protein 72 (Hsp72) expression of two-cell mouse embryos.Materials and Methods: In this experimental study, transcript analysis of Hsp72 gene was performed on non-vitrified and vitrified 2-cell mouse embryos via a nested quantitative polymerase chain reaction (nqPCR) subsequent to normalization with Hprt1 as the reference gene. The different cryoprotectant combinations were 15% (vit1:7.5% of each ethylene glycol (EG) and dimethyl sulfoxide (DMSO), 30% (vit2:15% EG + 15% DMSO) and control group with no cryoprotectants. Vitrified and fresh 2-cell embryos were cultured to obtain cleavage and blastocyst formation rates. The results were analyzed via one-way analysis of variance and the mean values were compared with least significant difference (LSD) (p< 0.05).Results: The relative expression of Hsp72 in vit2 (30% v/v) was significantly higher than vit1 (15% v/v). Survival rates were the same for both vitrification treatments and significantly lower than the control group. Cleavage and blastocyst rates in vit1 were significantly higher than vit2 while those in two vitrified groups were significantly lower than the control group.Conclusion: Our developmental data demonstrated that vit1 treatment (7.5% EG and 7.5% DMSO) was more efficient than vit2 (15% EG and 15% DMSO) in mouse embryos. The cryotopvitrification with two concentrations of cryoprotectants caused the relative changes of Hsp72 transcript level, but the stability of the gene in vit1 was significantly higher than vit2 and closer to the fresh 2-cell embryos