Search

An important question is what genes govern the differentiation of plant embryos into suspensor and embryo proper regions following fertilization and division of the zygote. We compared embryo proper and suspensor transcriptomes of four plants that vary in embryo morphology within the suspensor region. We determined that genes encoding enzymes in several metabolic pathways leading to the formation of hormones, such as gibberellic acid, and other metabolites are up-regulated in giant scarlet runner bean and common bean suspensors. Genes involved in transport and Golgi body organization are up-regulated within the suspensors of these plants as well, strengthening the view that giant specialized suspensors serve as a hormone factory and a conduit for transferring substances to the developing embryo proper. By contrast, genes controlling transcriptional regulation, development, and cell division are up-regulated primarily within the embryo proper. Transcriptomes from less specialized soybean and Arabidopsis suspensors demonstrated that fewer genes encoding metabolic enzymes and hormones are up-regulated. Genes active in the embryo proper, however, are functionally similar to those active in scarlet runner bean and common bean embryo proper regions. We uncovered a set of suspensor- and embryo proper-specific transcription factors (TFs) that are shared by all embryos irrespective of morphology, suggesting that they are involved in early differentiation processes common to all plants. Chromatin immunoprecipitation sequencing (ChIP-Seq) experiments with scarlet runner bean and soybean WOX9, an up-regulated suspensor TF, gained entry into a regulatory network important for suspensor development irrespective of morphology.

The precise mechanisms that control gene activity during seed development remain largely unknown. Previously, we showed that several genes essential for seed development, including those encoding storage proteins, fatty acid biosynthesis enzymes, and transcriptional regulators (e.g., ABI3, FUS3) are located within hypomethylated regions of the soybean genome. These hypomethylated regions are similar to the DNA methylation valleys (DMVs), or canyons, found in mammalian cells. Here, we address the question of the extent to which DMVs are present within seed genomes and what role they might play in seed development. We scanned soybean and Arabidopsis seed genomes from postfertilization through dormancy and germination for regions that contain

We profiled soybean and Arabidopsis methylomes from the globular stage through dormancy and germination to understand the role of methylation in seed formation. CHH methylation increases significantly during development throughout the entire seed, targets primarily transposable elements (TEs), is maintained during endoreduplication, and drops precipitously within the germinating seedling. By contrast, no significant global changes in CG- and CHG-context methylation occur during the same developmental period. An Arabidopsis ddcc mutant lacking CHH and CHG methylation does not affect seed development, germination, or major patterns of gene expression, implying that CHH and CHG methylation does not play a significant role in seed development or in regulating seed gene activity. By contrast, over 100 TEs are transcriptionally de-repressed in ddcc seeds, suggesting that the increase in CHH-context methylation may be a failsafe mechanism to reinforce transposon silencing. Many genes encoding important classes of seed proteins, such as storage proteins, oil biosynthesis enzymes, and transcription factors, reside in genomic regions devoid of methylation at any stage of seed development. Many other genes in these classes have similar methylation patterns, whether the genes are active or repressed. Our results suggest that methylation does not play a significant role in regulating large numbers of genes important for programming seed development in both soybean and Arabidopsis. We conclude that understanding the mechanisms controlling seed development will require determining how cis-regulatory elements and their cognate transcription factors are organized in genetic regulatory networks.

The purpose of this study was to investigate the possible responses to anomalous data obtained from experiments that are repeatable by carrying out additional or alternative experiments in the laboratory. Based on an analysis of responses from scientists to anomalous data taken from identification experiments on the Vinland Map, it was assumed that an additional response--uncertainty about interpretation of the data--should be considered in addition to the other eight responses reported by Chinn and Brewer [1998]. It was also assumed that a process of responses containing more than one response is possible for a given subject who is responding to a given piece of anomalous datum in the laboratory. Both assumptions were verified by examining responses of undergraduates to anomalous data obtained from repeatable laboratory experiments. The results of this study show that there are nine categories of responses: ignoring; rejection; uncertainty of validity; uncertainty of interpretation; exclusion; abeyance; reinterpretation; peripheral conceptual change; and conceptual change. Moreover, two categories of processing, "anomalous data-final response" (A-R process) and "anomalous data-[mediators with/without intermediate responses]-final response" (A-M-R process), are assessed in this study. It is suggested that science instructors could use the nine categories of responses to understand the learning characteristics of students, and also to use the A-M-R process to design suitable teaching strategies to arrive at meaningful learning.

Type II diabetes is the most important health issue in the whole world. Besides the use of prescribed drugs to control blood glucose level, recently, the development of health supplements is being actively explored. Owing to its high nutritional value, Momordica cochinchinensis Spreng. (Gac) is potentially a good source for developing this supplement. In recent years, the aril of Gac has been utilized as a substrate for developing various forms of supplements, but the pulp has been neglected as a byproduct. However, the pulp contains lots of phytochemicals that could provide health benefits, and the investigation using lactobacilli to ferment the pulp juices to lower blood glucose is not yet to be explored. Therefore, we set out to investigate the potential to develop the pulp-based juices for controlling blood glucose level by selecting an optimal strain of lactobacillus to ferment the pulp juice and measuring the inhibitory action of the fermented juice on α-glucosidase. This enzyme is crucial for controlling postprandial glucose absorbed into the bloodstream because it is the enzyme that hydrolyzes the carbohydrates to release glucose. First, we have successfully isolated a strain of lactobacillus which was capable of fermenting the pulp to produce α-glucosidase-inhibitory activity. Through a 16S rRNA sequence, this lactobacillus was named Lactiplantibacillus plantarum GBI 001. The optimal conditions for its growth in commercial culture medium were found to be 35 °C for 16 h to produce the highest α-glucosidase activity (72.03%). The optimal conditions for the strain to grow in Gac pulp juice were: 20% pulp juices as substrate with an initial pH adjusted to 4.0, growing at 35 °C for 16 h. Under these conditions, the fermented juice exhibited α-glucosidase activity of 24.36%, which is a 2.17-fold increase over the control group (11.23%). From its increase in α-glucosidase potency, using L. plantarum GBI 001 to ferment the pulp juices of Gac as soft drinks has great potential to develop a helpful drink as a food supplement to control postprandial blood glucose in patients with diabetes. [ABSTRACT FROM AUTHOR]