Persistent RNA Viruses of Common Bean (Phaseolus vulgaris): Distribution and Interaction with the Host and Acute Plant Viruses

Common bean (Phaseolus vulgaris) is the most important legume for direct human consumption. Common bean originated and was domesticated in the Americas but now is grown worldwide. As in the case of other crops, common bean can be infected with acute and persistent plant viruses. A modified dsRNA extraction method was developed and used in this study. The method was fast, economic, versatile, and required relatively small amounts of desiccated plant tissue. The method was successfully used to extract dsRNAs from plants infected with RNA plant viruses and to investigate the occurrence of two endornaviruses, Phaseolus vulgaris endornavirus 1 (PvEV1) and Phaseolus vulgaris endornavirus 2 (PvEV2), in breeding lines, cultivars, landraces, and wild genotypes of common bean from the two centers of common bean domestication: Mesoamerica and the Andes. The two endornaviruses were detected in many common bean genotypes of Mesoamerican origin but rarely in genotypes of Andean origin. A comparative study of morphological and physiological characteristics between two common bean lines of the cultivar Black Turtle Soup (BTS); one infected with PvEV1 and PvEV2 (BTS+) and the other endornavirus-free (BTS-) was conducted. Morphological differences between the two lines were not observed. However, the study revealed that common bean endornaviruses may promote seed germination, pod length, and carotenoid content. Nevertheless, endornaviruses were associated with lower chlorophyll content. When interactions studies were conducted between PvEV1 and PvEV2 and three acute viruses, synergistic effects were obtained. Quantitative RT-PCR results supported a synergism between PvEV1 and Sunn-hemp mosaic virus. More research should be conducted to determine the type of symbiotic interaction that exists between common bean and endornaviruses

Biological and molecular interactions between bell pepper endornavirus and two tobamoviruses

Peppers (Capsicum spp.) are native plants to the Americas. They are cultivated worldwide for direct human consumption and industrial purposes. Peppers can be infected by acute plant viruses, which cause a variety of diseases and crop losses. However, many Capsicum species can also be infected by persistent viruses. These are emerging viruses and they do not cause apparent disease and are transmitted only vertically. Using two near-isogenic lines of bell pepper cv. Marengo, biological and molecular interactions between the persistent virus bell pepper endornavirus (BPEV) and two acute viruses, pepper mild mottle virus (PMMoV) and tobacco mild green mosaic virus (TMGMV), were evaluated by symptom expression, enzyme-linked immunosorbent assay, and RT-qPCR. The relative titer of BPEV decreased at least two-fold at 14 days after infection when BPEV-infected plants were single infected with TMGMV or in mixed infection of PMMoV and TMGMV. The presence of BPEV was associated with symptom reduction in pepper plants infected with single and mixed infections of PMMoV and TMGMV. This suggests that the ubiquitous infection of BPEV may trigger the plant immune response, and therefore, BPEV is active when the plant is infected with PMMoV and/or TMGMV

Physiological traits of endornavirus?infected and endornavirus?freecommon bean (Phaseolus vulgaris) cv Black Turtle Soup

AbstractThis study evaluated the physiological traits of eight lines of common bean (Phaseolus vulgaris) cv. Black Turtle Soup,four of which were double-infected with Phaseolus vulgaris endornavirus 1 and Phaseolus vulgaris endornavirus 2, andfour of which were endornavirus-free. Plants from all eight lines were morphologically similar and did not show statisticallysignificant differences in plant height, wet weight, number of days to flowering and pod formation, pods per plant, podthickness, seed size, number of seeds per pod, and anthocyanin content. However, the endornavirus-infected lines had fasterseed germination, longer radicle, lower chlorophyll content, higher carotene content, longer pods, and higher weight of 100seeds, all of which were statistically significant. The endornaviruses were not associated with visible pathogenic effects

Sanguinarine and Chelidonine Synergistically Induce Endosomal Toll-like Receptor and M1-Associated Mediators Expression

Natural compounds represent the great capability to stimulate several cell types. Macrophage plays an important role for an effective immune response for infection and inflammation. Isoquinoline alkaloid, sanguinarine, and chelidonine are active compounds that exhibit activity on various tumor cells and immune cells. However, the effect of these compounds on the endosomal toll-like receptor (enTLR) and type I interferon (IFN) are still unclear. The monocyte-derived macrophages (MDMs) were cultured and were determined their cell viability and phagocytic activity to Staphylococcus aureus DMST8840. The nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression were also examined. The expression of enTLRs, type I IFN, and cytokines were determined by real-time PCR. Result shows that the compounds did not affect on MDM cell viability. Sanguinarine and chelidonine enhance phagocytic activity of MDM against Staphylococcus aureus DMST8840 by revealing a higher number of bacterial survival than the MDM treated by polyI:C, and the cell control after co-culture for 3 h. The production of NO has no difference amount but iNOS mRNA production was down-regulated in sanguinarine, chelidonine and their mixed treated MDM. The expressions of enTLRs and IFN-β1 mRNA were up-regulated in both compounds and their combination. Additionally, these compounds also enhance M1-liked cytokine by up-regulated IL-6 and down-regulated IL-10 and TGF-β1, respectively. Therefore, sanguinarine and chelidonine enhance enTLR and IFN-β1 expression and trend to stimulate the cell into M1-liked MDM

A predictive model of the impact of urbanization on bacterial loads in watersheds

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