Zhang X.-H.,Florida Atlantic University |
Brotherton J.E.,Converse College |
Widholm J.M.,Urbana University
In Vitro Cellular and Developmental Biology - Plant | Year: 2015
Anthranilate synthase (AS), a tetramer consisting of two α subunits and two β subunits, is the key control enzyme in the tryptophan (Trp) biosynthesis pathway. A naturally occurring α subunit of AS called ASA2 that is insensitive to Trp feedback inhibition was isolated from a tobacco suspension cell culture and has been extensively studied and used for both nuclear and plastid transformation. However, the obligate β subunit of AS had not been studied in tobacco. Therefore, the tobacco AS β subunit-encoding cDNA was cloned and its encoded protein was verified. Agrobacterium-mediated transformation of tobacco plants was performed, under the selection of the toxic Trp analogs, 7-methyltryptophan or α-methyltryptophan, with a construct containing both ASA2 and AS β subunit genes. Many transgenic plants overexpressing both subunits were identified and examined. Compared to the wild-type plants, the transgenic plants had higher levels of enzymatic activities for both holoenzyme and α subunit. The transgenic plants had 9 to 68 times the amount of free Trp as the wild-type plants, which was more pronounced than plants overexpressing ASA2 alone. This study demonstrates the potential of co-expressing AS α and β subunits as a robust plant transformation system as well as overcoming feedback inhibition to obtain high levels of Trp biosynthesis. © 2015 The Society for In Vitro Biology
Li P.,University of South Carolina |
Maier J.M.,University of South Carolina |
Hwang J.,University of South Carolina |
Smith M.D.,University of South Carolina |
And 4 more authors.
Chemical Communications | Year: 2015
A dynamic intramolecular charge-transfer (CT) complex was designed that displayed reversible colour changes in the solid-state when treated with different organic solvents. The origins of the dichromatism were shown to be due to solvent-inclusion, which induced changes in the relative orientations of the donor pyrene and acceptor naphthalenediimide units. © 2015 The Royal Society of Chemistry.
Walker M.,Converse College
Agricultural History | Year: 2012
Agrarian ideology-the celebration of farming and rural life for the benefit it brings to individuals and the nation-has become part of a widespread national discourse about what we eat and how we live. This essay examines major tenets of new agrarian thinking and offers a critique of many of the assumptions that underlie the new agrarian movement. The author argues that incremental changes in consumer behavior can only achieve incremental improvements in the food system and that true systemic change depends on a fundamental alteration of in federal agricultural policy. © the Agricultural History Society, 2012.
Kowalski R.M.,Clemson University |
Fedina C.,Converse College
Research in Autism Spectrum Disorders | Year: 2011
Cyber bullying or electronic bullying refers to bullying that occurs through the Internet or cellular phones. With the rise of technology, researchers have shown a keen interest in the topic of cyber bullying. However, that interest has not extended to individuals with special needs. To address this gap in the literature, the current study examined the prevalence of both "traditional" bullying and cyber bullying in youth with ADHD and/or Asperger's Syndrome, and assessed the social, psychological, and health effects of bullying on participants. In addition, the study addressed the disconnect between parents' understanding of their child's online experiences and their child's actual experiences in the virtual world. Forty-two children and youth reported high rates of bullying victimization through both traditional and electronic means. Individuals not involved with bullying showed greater levels of physical and psychological health relative to those involved with bullying. Parents and children disagreed on a number of issues related to use of the Internet, indicating the need for more clear communication between parents and their children. The results are discussed in terms of theory of mind, both for self and for others. © 2011 Elsevier Ltd. All rights reserved.
Jensen D.P.,Converse College |
Gensel P.G.,University of North Carolina at Chapel Hill
International Journal of Plant Sciences | Year: 2013
Premise of research. The zosterophylls are a group of primitive land plants that possess comparatively few characters useful in taxonomic distinction but vary considerably among these characters, such that a large number of genera and species are currently recognized. We studied specimens of a novel Early Devonian plant from New Brunswick, Canada, that further extends known variation within Zosterophyllopsida sensu Kenrick and Crane. After careful reevaluation of character and character-state utility in taxonomic circumscription among these simple early plants, we recognize this plant as a new genus and species, Forania plegiospinosa. Methodology. Preserved as adpressions, specimens were prepared with the standard paleobotanical techniques of de ́gagement and maceration, with appropriate parts figured via LM. Pivotal results. Forania plegiospinosa is interpreted to be a decumbent plant, bearing stout, mostly retrorsely curved, spine-like emergences arranged in two rows along the axes, variable modes of branching, circinately coiled axes, lateral buds, and sparsely scattered, circular to reniform lateral sporangia. Cuticular features of this species include polygonal epidermal cells and anomocytic sporangia. This plant provides the first documented evidence of stomata on emergences. The presence of stomata on the bases of large emergences suggests that emergence volume is a factor in stomatal location and development. Conclusions. Criteria for establishing new genera are discussed in the context of the mosaic of characters found among these early plants. Forania exhibits a unique combination of characters that is consistent with other zosterophylls at the generic level. It best fits within the Sawdoniaceae sensu Kenrick and Crane, although its sporangia are solitary rather than in two rows. © 2013 by The University of Chicago. All rights reserved.