Inorganic nitrogen availability alters Eucalyptus grandis receptivity to the ectomycorrhizal fungus Pisolithus albus but not symbiotic nitrogen transfer.

Forest trees are able to thrive in nutrient-poor soils in part because they obtain growth-limiting nutrients, especially nitrogen (N), through mutualistic symbiosis with ectomycorrhizal (ECM) fungi. Addition of inorganic N into these soils is known to disrupt this mutualism and reduce the diversity of ECM fungi. Despite its ecological impact, the mechanisms governing the observed effects of elevated inorganic N on mycorrhizal communities remain unknown. We address this by using a compartmentalized in vitro system to independently alter nutrients to each symbiont. Using stable isotopes, we traced the nutrient flux under different nutrient regimes between Eucalyptus grandis and its ectomycorrhizal symbiont, Pisolithus albus. We demonstrate that giving E. grandis independent access to N causes a significant reduction in root colonization by P. albus. Transcriptional analysis suggests that the observed reduction in colonization may be caused, in part, by altered transcription of microbe perception genes and defence genes. We show that delivery of N to host leaves is not increased by host nutrient deficiency but by fungal nutrient availability instead. Overall, this advances our understanding of the effects of N fertilization on ECM fungi and the factors governing nutrient transfer in the E. grandis-P. microcarpus interaction

Inclusion of English language learners in conversion small schools

Small school reform is an increasingly popular reform in urban comprehensive high schools. Efforts to divide large high schools into small school groups have been funded by The Bill and Melinda Gates Foundation as well as by the Coalition of Essential Schools (CES). The Coalition of Essential Schools is a network of small schools that adhere to similar educational ideologies such as the desirability to provide inclusive educational environments. CES promotes inclusion as a means to equitable and democratic education. This study explains the tensions the philosophy and practice of inclusion has produced concerning English language learner (ELL) programs in conversion small schools. This study investigates (a) the ways in which ELL programs in conversion small schools have supported inclusive education, (b) the ways small school inclusion has affected ELL programs, and (c) the impact inclusion philosophy in conversion small schools on inclusive and equitable instruction for ELL students. Through a multi-case qualitative study including interviews and observations, the contexts for the ELL programs in three different conversion schools are investigated and described. The data shows that none of the ELL programs investigated have been able to fully support instructional inclusion either due to a lack of belief in the efficacy of inclusion or a lack of resources. Small school inclusion has affected ELL programs differently in each school. At one school, the ELL program felt almost no effects of the conversion. At another, the program is radically different than previous to the conversion. Third, inclusive and equitable instruction for ELL students in conversion small schools, even in the best case, is happening only in some classes. Due to a lack of resources, no ELL program has been able to implement inclusion as a programmatic reform. Finally, the impetus to involve ELL students in inclusion programs is highly influenced by special education policies rather than by legislation overseeing ELLs. The study concludes that inclusion is understood and practiced differently at each site. At the sites where any type of inclusion was practiced, teachers reported that inclusion provided ELL students with more social than academic benefits

Moving between opposing worlds : the moral experiences of white, anti-racism educators in Saskatchewan

This research explores the moral experiences of White, anti-racism educators in Saskatchewan. As members of the dominant group, while at the same time being defenders of the rights of minority groups, the unique positioning of these individuals raises intriguing questions of moral experience. Although there is a large body of research regarding issues of racism, there is very little research focusing on the experiences of individuals working in the field of anti-racism; this research seeks to address this gap in the literature. Using a critical interpretive approach (Lock and Scheper-Hughes, 1990) grounded in the assumptions of constructionism, and relying upon Kleinman’s (1995; 1999) theory of moral experience, I interviewed 12 self-identified White, anti-racism educators using an open-ended life-history interview followed by a semi-structured interview. The interview questions were inspired by the racism literature reviewed; my own experiences as a White woman negotiating my place in the study of racism; Kleinman’s theory of moral experience; and a collection of secondary theories deemed potentially useful to understanding various dimensions of participants’ experience. Four broad domains of moral experience are identified and explored in this research. First, participants’ understandings of race, racism, and anti-racism are examined. Veyne’s (1988) theory regarding the plurality of “programs of truths” is used to make sense of what might be read as contradictions in participants’ constructions of these concepts. Second, the experience of actually doing anti-racism education is considered in terms of participants’ descriptions of their involvements; which they frame alternately as educating Whites, ‘helping’ the racialized, and changing racist structures. Foucault’s (1977, 1978) theory of power and de Certeau’s notion of tactics (1984) prove relevant to understanding aspects of participants’ experiences in this domain. Third, the relationships between Self and various Others (i.e., the White Other, the racialized Other, the anti-racism Other) are explored. Todorov’s (1984) typology of the Other is used to make sense of these complex data. Finally, participants’ descriptions of their experiences of Self (including past, present, and future Selves) are examined. Goffman’s (1961) theory of moral career and Turner’s (1995) theory of liminality are applied to understanding elements of participants’ varied experiences of Self. In reviewing participants’ accounts across these broad domains, I argue that their noted success and confidence in navigating a challenging moral landscape might be understood in terms of their skill in moving between dual worlds that operate according to distinct logics of morality. Potential applications for the field of anti-racism are discussed

The ectomycorrhizal fungus Pisolithus microcarpusencodes a microRNA involved in cross-kingdom gene silencing during symbiosis

Small RNAs (sRNAs) are known to regulate pathogenic plant-microbe interactions. Emerging evidence from the study of these model systems suggests that microRNAs (miRNAs) can be translocated between microbes and plants to facilitate symbiosis. The roles of sRNAs in mutualistic mycorrhizal fungal interactions, however, are largely unknown. In this study, we characterized miRNAs encoded by the ectomycorrhizal fungus Pisolithus microcarpus and investigated their expression during mutualistic interaction with Eucalyptus grandis. Using sRNA sequencing data and in situ miRNA detection, a novel fungal miRNA, Pmic_miR-8, was found to be transported into E. grandis roots after interaction with P. microcarpus. Further characterization experiments demonstrate that inhibition of Pmic_miR-8 negatively impacts the maintenance of mycorrhizal roots in E. grandis, while supplementation of Pmic_miR-8 led to deeper integration of the fungus into plant tissues. Target prediction and experimental testing suggest that Pmic_miR-8 may target the host NB-ARC domain containing transcripts, suggesting a potential role for this miRNA in subverting host signaling to stabilize the symbiotic interaction. Altogether, we provide evidence of previously undescribed cross-kingdom sRNA transfer from ectomycorrhizal fungi to plant roots, shedding light onto the involvement of miRNAs during the developmental process of mutualistic symbioses