Crops lack genetic resistance to most necrotrophic pathogens. To compensate for this disadvantage, plants recruit antagonistic members of the soil microbiome to defend their roots against pathogens and other pests. The best examples of this microbially based defense of roots are observed in disease-suppressive soils in which suppressiveness is induced by continuously growing crops that are susceptible to a pathogen, but the molecular basis of most is poorly understood. Here we report the microbial characterization of a Korean soil with specific suppressiveness to Fusarium wilt of strawberry. In this soil, an attack on strawberry roots by Fusarium oxysporum results in a response by microbial defenders, of which members of the Actinobacteria appear to have a key role. We also identify Streptomyces genes responsible for the ribosomal synthesis of a novel heat-stable antifungal thiopeptide antibiotic inhibitory to F. oxysporum and the antibiotic’s mode of action against fungal cell wall biosynthesis. Both classical- and community-oriented approaches were required to dissect this suppressive soil from the field to the molecular level, and the results highlight the role of natural antibiotics as weapons in the microbial warfare in the rhizosphere that is integral to plant health, vigor and development.

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Although adipose-derived stem cells (ADSCs) have many advantageous traits compared with other postnatal stem cells, the consensus is that their differentiation potential must be improved to allow their practical utilization. During the in vitro expansion of human ADSCs (hADSCs), pre-treatment of fibroblast growth factor 2 (FGF2) not only induced an increase of approximately 44-fold in cell number at passage 7 but also augmented the differentiation potential of hADSCs. The effect of FGF2-induced cell preconditioning was evaluated by in vitro and in vivo osteogenesis after pre-treatment with various concentrations of FGF2 (0, 5, 25 ng/ml). FGF2-pre-treated hADSCs showed enhanced in vitro osteogenesis. An evaluation of in vivo osteogenic potential with an ectopic bone model showed that FGF2-preconditioned hADSCs produced an abundant osteoid/bone matrix and the effect was dependent on the concentration of FGF2 pre-treatment; bone matrix formation by control hADSCs was virtually non-existent. FGF2-pre-treated hADSCs also showed enhanced in vitro chondrogenesis, whereas no significant difference was observed in adipogenic potential. Pre-treatment of hADSCs with FGF2 induced an increase in the expression of osteogenic markers such as Cbfa1/Runx2 and alkaline phosphatase and in the expression of β-catenin. These results suggest that FGF2 plays a highly beneficial role in the preconditioning of ADSCs for musculoskeletal tissue engineering.

The impact of COVID-19 on conducting research is far-reaching, especially for those scholars working for or alongside communities. As the pandemic continues to create and exacerbate many of the issues that communities at the margins faced pre-pandemic, such as health disparities and access to resources, it also creates particular difficulties in collaborative, co-developed participatory research and scholar-activism. These forms of community engagement require the commitment of researchers to look beyond the purview of the racialized capitalist and neoliberal structures and institutions that tend to limit the scope of our research and engagement. Both the presence of the researcher within the community as well as deep community trust in the researcher is required in order to identify and prioritize local, often counter-hegemonic forms of knowledge production, resources, and support networks. The pandemic and similar conditions of crises has likely limited opportunities for building long-term, productive relationships of mutual trust and reciprocity needed for PAR while communities refocus on meeting basic needs. The pandemic has now not only exacerbated existing disparities and made the need for engaged, critical and co-creative partnerships even greater, it has also abruptly halted opportunities for partnerships to occur, and further constrained funds to support communities partnering with researchers. In this paper we highlight accomplishments and discuss the many challenges that arise as participatory action researchers are displaced from the field and classroom, such as funding obstacles and working remotely. An analysis of experiences of the displacement of the scholar exposes the conflicts of conducting PAR during crises within a state of academic capitalism. These experiences are drawn from our work conducting PAR during COVID-19 around the globe, both in urban and rural settings, and during different stages of engagement. From these findings the case is made for mutual learning from peer-experiences and institutional support for PAR. As future crises are expected, increased digital resources and infrastructure, academic flexibility and greater consideration of PAR, increased funding for PAR, and dedicated institutional support programs for PAR are needed.

Reconstruction of elastic cartilage requires a source of chondrocytes that display a reliable differentiation tendency. Predetermined tissue progenitor cells are ideal candidates for meeting this need; however, it is difficult to obtain donor elastic cartilage tissue because most elastic cartilage serves important functions or forms external structures, making these tissues indispensable. We found vestigial cartilage tissue in xiphoid processes and characterized it as hyaline cartilage in the proximal region and elastic cartilage in the distal region. Xiphoid process-derived chondrocytes (XCs) showed superb in vitro expansion ability based on colony-forming unit fibroblast assays, cell yield, and cumulative cell growth. On induction of differentiation into mesenchymal lineages, XCs showed a strong tendency toward chondrogenic differentiation. An examination of the tissue-specific regeneration capacity of XCs in a subcutaneous-transplantation model and autologous chondrocyte implantation model confirmed reliable regeneration of elastic cartilage regardless of the implantation environment. On the basis of these observations, we conclude that xiphoid process cartilage, the only elastic cartilage tissue source that can be obtained without destroying external shape or function, is a source of elastic chondrocytes that show superb in vitro expansion and reliable differentiation capacity. These findings indicate that XCs could be a valuable cell source for reconstruction of elastic cartilage. STEM CELLS