Downregulation of Cinnamyl-Alcohol Dehydrogenase in Switchgrass by RNA Silencing Results in Enhanced Glucose Release after Cellulase Treatment

Cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in monolignol biosynthesis and genetic evidence indicates CAD deficiency in grasses both decreases overall lignin, alters lignin structure and increases enzymatic recovery of sugars. To ascertain the effect of CAD downregulation in switchgrass, RNA mediated silencing of CAD was induced through Agrobacterium mediated transformation of cv. “Alamo” with an inverted repeat construct containing a fragment derived from the coding sequence of PviCAD2. The resulting primary transformants accumulated less CAD RNA transcript and protein than control transformants and were demonstrated to be stably transformed with between 1 and 5 copies of the T-DNA. CAD activity against coniferaldehyde, and sinapaldehyde in stems of silenced lines was significantly reduced as was overall lignin and cutin. Glucose release from ground samples pretreated with ammonium hydroxide and digested with cellulases was greater than in control transformants. When stained with the lignin and cutin specific stain phloroglucinol-HCl the staining intensity of one line indicated greater incorporation of hydroxycinnamyl aldehydes in the lignin

‘It’s different for guys’: Gendered narratives of racial conflict among white California youth

As race talk has gained attention throughout the social sciences, sociocultural linguistics has become crucial in revealing how racial ideologies and identities are discursively produced. This article examines how race talk may reproduce racial binaries while perpetuating gender ideologies. Drawing on ethnographically collected narratives of conflict at an ethnoracially divided California high school, the analysis examines three discursive practices of racial reversal whereby white youth portray themselves as disadvantaged vis-a-vis their black peers: claims of ‘reverse discrimination’, narratives of racialized fear, and fight stories. Whereas white girls’ narratives relied on racial vagueness, white boys’ narratives highlighted racial difference, contrastive strategies that indicate the different racial stakes for white girls versus white boys at the school. The article demonstrates the necessity of examining race talk not only for its content but also for its discursive structure, its ethnographic and interactional context, its co-construction by the researcher, and its ideological effects

Co-constructing the adolescent’s identity: agency and autonomy as interactional accomplishments

Drawing on recent linguistic anthropological reflections on identity and discursive psychologists’ theorizing on social positioning, the authors of this chapter examine the dynamic and multifaceted enactment and transformation of identity in social interaction. The work presentd in this chapter suggests that agency and autonomy, key dimensions of adolescent identity development, do not emerge solely from the individual but are co-constructed and transformed in interpersonal exchanges. These theoretical propositions are supported through the discourse analysis of two family cases, which reveals that the discursive co-construction of adolescent agency and autonomy is non-linear and continuously negotiated. Families oscillate between different interactional configurations, with individual family members claiming, declining, reclaiming certain roles and competencies vis-à-vis other members of the family. In addition to illustrating the value of bridging different disciplinary perspectives together in the work presented in this chapter, the authors demonstrate the analytic purchase that a micro-examination of social interaction offers to adolescence and developmental psychology research