Localised alterations in cytoplasmic Ca 2+ levels are an integral part of the response of eukaryotic cells to a plethora of external stimuli. Due to the large size of nuclear pores, it has generally been assumed that intranuclear Ca 2+ levels reflect the prevailing cytoplasmic Ca 2+ levels. Using nuclei prepared from carrot (Daucus carota L.) cells, we now show that Ca 2+ can be transported across nuclear membranes in an ATP-dependent manner and that over 95% of Ca 2+ is accumulated into a pool releasable by the Ca 2+ ionophore A.23187. ATP-dependent nuclear Ca 2+ uptake did not occur in the presence of ADP or ADPQ QS and was abolished by orthovanadate. Confocal microscopy of nuclei loaded with dextran-linked Indo-1 showed that the initial ATP-induced rise in [Ca 2+ ] occurs in the nuclear periphery. The occurrence of ATP-dependent Ca 2+ uptake in plant nuclei suggests that alterations of intranuclear Ca 2+ levels may occur independently of cytoplasmic [Ca 2+ ] changes. ß

Infection and fungal development of Tubakia dryina were investigated on leaves of sweet gum using a combination of microscopic techniques. Conidia of T. dryina adhered to the leaf surface and formed septate germ tubes. Germ tubes terminated in small appressoria that formed directly over epidermal cells. Intra-and intercellular hyphae ramified extensively throughout the leaf tissue. Host cells associated with the infection site became necrotic and collapsed, resulting in macroscopic disease symptoms.

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Rotavirus (RV) causes severe diarrhea in young children and immunocompromised individuals. Several effective vaccines have been developed to immunize children between 2 to 8 months of age, but there are no vaccines or antiviral therapeutics for RV‐infected immunocompromised patients of any age. Our laboratory has shown a decrease in the number of infectious RV particles produced in HT29.f8 cells with the addition of the stilbenoid, arachidin‐3 (A3). Additionally, the viral protein, NSP4, that is important for viral replication is decreased, suggesting an effect on virus replication. Also, ultrastructural changes were observed with TEM studies that imply a connection with the apoptosis and autophagy pathways which is supported by qRT PCR data. Recently, a synthetic A3 (sA3) has been developed. This study compared the effects of the natural A3 and sA3 on HT29.f8 cell viability, production of infectious RV particles, production of structural and nonstructural viral proteins, ultrastructural changes and the gene regulation of apoptosis and autophagy transcripts. From the data collected, the viability of the cells was not affected with the introduction of either natural or sA3, but the amount of infectious virus particles produced was significantly decreased by 50‐fold, respectively. The TEM images depicted changes in ultrastructures of RV‐infected HT29.f8 cells that appear to show signs of apoptosis while RV‐infected cells with the addition of either the natural or synthetic A3 showed a more normal appearance like the negative controls. The nucleus to cytoplasm ratios of TEM micrographs of RV‐infected cells was greater than 1.0 whereas the arachidin treated RV‐infected cells was about 0.5 which was like the control cells. To validate this data, whole cell staining of the nucleus and cytoplasm showed similar changes with the addition of both the A3 and sA3. qRT PCR analysis of transcripts for genes that are important in regulating the apoptosis and autophagy pathways regulations corroborated the TEM observation, and suggests a cross talk between the two pathways during an RV infection that is regulated with the addition of the arachidins. Our data suggests that both the natural A3 and sA3 have anti‐RV activity that implies a potential therapeutic application.Support or Funding InformationThis work was supported by: 1) The Faculty‐Student Collaborative Research Program of The Office of Research and Sponsored Programs at Stephen F. Austin State University and 2) The NSF‐EPSCoR (grant# EPS‐ 0701890; Center for Plant‐Powered Production‐P3).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.