Application of Laser Microdissection to plant pathogenic and symbiotic interactions

Abstract Laser Microdissection (LM) is a technology that allows the rapid procurement of selected cell populations from a section of heterogeneous tissues in a manner conducive to the extraction of DNA, RNA, proteins and even metabolites. In the past few years, it has also been applied to plant biology in order to study gene expression in plant-nematode and plant-microbe interactions. LM represents a powerful tool since cells associated with a particular infection stage can be visualized under the microscope and harvested. Therefore, verification of the response of the plant during the progression of the colonization can be performed in different cell types. Applications of LM to study the interaction between the plant and both pathogenic and symbiotic organisms (i.e. nematode and fungi, respectively) are explored in this review

Is Tuber brumale a threat to T. melanosporum and T. aestivum plantations?

True truffles in the genus Tuber are the most valuable ectomycorrhizal fungiand their cultivation has become widespread around the world. Competition with other ectomycorrhizal fungi and especially with undesired Tuber species, like T. brumale, can threaten the success of a truffle plantation. In this work, the competitiveness of T. brumale towards T. melanosporum and T. aestivum was assessed in a 14 year-old plantation carried out planting seedlings inoculated with these three truffle species in adjacent plots. Analyses of both truffle ectomycorrhizas and extra-radical mycelium were carried out in the transects separating the T. brumale plot from T. melanosporum and T. aestivum plots. The results confirm the competitiveness of T. brumale against T. aestivum and T. melanosporum due to its major ability to colonize the soil around its ectomycorrhizas. However, its competitiveness is limited to the transect areas and it was never found inside T. melanosporum plot. These results remark that, in presence of optimal conditions for T. melanosporum and T. aestivum, the greatest risk of contamination with T. brumale is due to wrong greenhouse activity

Sterilization of lung matrices by supercritical carbon dioxide

Lung engineering is a potential alternative to transplantation for patients with end-stage pulmonary failure. Two challenges critical to the successful development of an engineered lung developed from a decellularized scaffold include (i) the suppression of resident infectious bioburden in the lung matrix, and (ii) the ability to sterilize decellularized tissues while preserving the essential biological and mechanical features intact. To date, the majority of lungs are sterilized using high concentrations of peracetic acid (PAA) resulting in extracellular matrix (ECM) depletion. These mechanically altered tissues have little to no storage potential. In this study, we report a sterilizing technique using supercritical carbon dioxide (ScCO(2)) that can achieve a sterility assurance level 10(−6) in decellularized lung matrix. The effects of ScCO(2) treatment on the histological, mechanical, and biochemical properties of the sterile decellularized lung were evaluated and compared with those of freshly decellularized lung matrix and with PAA-treated acellular lung. Exposure of the decellularized tissue to ScCO(2) did not significantly alter tissue architecture, ECM content or organization (glycosaminoglycans, elastin, collagen, and laminin), observations of cell engraftment, or mechanical integrity of the tissue. Furthermore, these attributes of lung matrix did not change after 6 months in sterile buffer following sterilization with ScCO(2), indicating that ScCO(2) produces a matrix that is stable during storage. The current study's results indicate that ScCO(2) can be used to sterilize acellular lung tissue while simultaneously preserving key biological components required for the function of the scaffold for regenerative medicine purposes

Key issues in professionalizing mentoring practices

Mentoring has experienced a tremendous upswing over the past decades, which has only recently slowed down somewhat. One possible factor explaining mentoring's popularity are numerous case studies suggesting that it is one of the most effective ways of helping individuals to develop. Meta‐analyses indicating effect sizes for mentoring that are below what would theoretically be possible appear to contradict the success stories, however. This circumstance raises questions about the professionalization of mentoring practices. We focus on seven key issues for future efforts at professionalizing mentoring. Key issues 1 and 2 address observation of the state of the art within formal mentoring when programs are planned and implemented: the consideration of recent research and of best practices. While both areas can overlap, they provide complementary sources of pertinent information for the professionalization of mentoring. Key issues 3–6 address the need to align mentoring activities to the specific context and goals of individual mentoring programs by observing idiographic program characteristics, mentoring dynamics, the orchestration of mentoring goals, and the provision of mentoring resources. Finally, key issue 7 highlights ongoing evaluation as the basis of the effective, continuous improvement of mentoring programs

The in vivo effect of chelidonine on the stem cell system of planarians

The presence of adult pluripotent stem cells and the amazing regenerative capabilities make planarian flatworms an extraordinary experimental model to assess in vivo the effects of substances of both natural and synthetic origin on stem cell dynamics. This study focuses on the effects of chelidonine, an alkaloid obtained from Chelidonium majus. The expression levels of molecular markers specific for stem or differentiated cells were compared in chelidonine-treated and control planarians. The use of these markers demonstrates that chelidonine produces in vivo a significant anti-proliferative effect on planarian stem cells in a dosedependent fashion. In response to chelidonine treatment mitotic abnormalities were also observed and the number of cells able to proceed to anaphase/telophase appeared significantly reduced with respect to the controls. Our results support the possibility that chelidonine acts on cell cycle progression by inhibition of tubulin polymerization. These studies provide a basis for preclinical evaluation in vivo of the effects of chelidonine on physiologically proliferating stem cells