@article{dye_muga_mwangi_hoyer_ly_rosado_sharpee_mware_wambugu_labadie_et al._2023, title={Cassava begomovirus species diversity changes during plant vegetative cycles}, volume={14}, ISSN={1664-302X}, url={http://dx.doi.org/10.3389/fmicb.2023.1163566}, DOI={10.3389/fmicb.2023.1163566}, abstractNote={Cassava is a root crop important for global food security and the third biggest source of calories on the African continent. Cassava production is threatened by Cassava mosaic disease (CMD), which is caused by a complex of single-stranded DNA viruses (family: Geminiviridae, genus: Begomovirus) that are transmitted by the sweet potato whitefly (Bemisia tabaci). Understanding the dynamics of different cassava mosaic begomovirus (CMB) species through time is important for contextualizing disease trends. Cassava plants with CMD symptoms were sampled in Lake Victoria and coastal regions of Kenya before transfer to a greenhouse setting and regular propagation. The field-collected and greenhouse samples were sequenced using Illumina short-read sequencing and analyzed on the Galaxy platform. In the field-collected samples, African cassava mosaic virus (ACMV), East African cassava mosaic virus (EACMV), East African cassava mosaic Kenya virus (EACMKV), and East African cassava mosaic virus-Uganda variant (EACMV-Ug) were detected in samples from the Lake Victoria region, while EACMV and East African mosaic Zanzibar virus (EACMZV) were found in the coastal region. Many of the field-collected samples had mixed infections of EACMV and another begomovirus. After 3 years of regrowth in the greenhouse, only EACMV-like viruses were detected in all samples. The results suggest that in these samples, EACMV becomes the dominant virus through vegetative propagation in a greenhouse. This differed from whitefly transmission results. Cassava plants were inoculated with ACMV and another EACMV-like virus, East African cassava mosaic Cameroon virus (EACMCV). Only ACMV was transmitted by whiteflies from these plants to recipient plants, as indicated by sequencing reads and copy number data. These results suggest that whitefly transmission and vegetative transmission lead to different outcomes for ACMV and EACMV-like viruses.}, journal={Frontiers in Microbiology}, publisher={Frontiers Media SA}, author={Dye, Anna E. and Muga, Brenda and Mwangi, Jenniffer and Hoyer, J. Steen and Ly, Vanessa and Rosado, Yamilex and Sharpee, William and Mware, Benard and Wambugu, Mary and Labadie, Paul and et al.}, year={2023}, month={May} }
 @article{kennedy_sharpee_jacobson_wambugu_mware_hanley-bowdoin_2023, title={Genome segment ratios change during whitefly transmission of two bipartite cassava mosaic begomoviruses}, volume={13}, ISSN={2045-2322}, url={http://dx.doi.org/10.1038/s41598-023-37278-8}, DOI={10.1038/s41598-023-37278-8}, abstractNote={AbstractCassava mosaic disease is caused by a complex of whitefly-transmitted begomoviruses, which often occur in co-infections. These viruses have bipartite genomes consisting of DNA-A and DNA-B that are encapsidated into separate virions. Individual viruses exist in plants and whitefly vectors as populations comprising both genome segments, which can occur at different frequencies. Both segments are required for infection, and must be transmitted for virus spread to occur. Cassava plants infected with African cassava mosaic virus (ACMV) and/or East African cassava mosaic Cameroon virus (EACMCV), in which the ratios of DNA-A:DNA-B titers differed between plants, were used to examine how titers of the segments in a plant relate to their respective probabilities of acquisition by whiteflies and to the titers of each segment acquired and subsequently transmitted by whiteflies. The probabilities of acquiring each segment of ACMV did not reflect their relative titers in the source plant but they did for EACMCV. However, for both viruses, DNA-A:DNA-B ratios acquired by whiteflies differed from those in the source plant and the ratios transmitted by the whitefly did not differ from one – the ratio at which the highest probability of transmitting both segments is expected.}, number={1}, journal={Scientific Reports}, publisher={Springer Science and Business Media LLC}, author={Kennedy, George G. and Sharpee, William and Jacobson, Alana L. and Wambugu, Mary and Mware, Benard and Hanley-Bowdoin, Linda}, year={2023}, month={Jun} }
 @misc{sharpee_dean_2016, title={Form and function of fungal and oomycete effectors}, volume={30}, ISSN={["1878-0253"]}, DOI={10.1016/j.fbr.2016.04.001}, abstractNote={Plants are able to recognize conserved features of potential microbial invaders and mount an active defense in most cases. Over the course of evolution, a number of these microbes including plant pathogenic fungi and oomycetes have evolved means through the secretion of small molecules (effectors) to block these defenses and promote virulence. In recent years, research has uncovered a wealth of knowledge regarding how effectors function within the plant cell to promote disease. Function of effectors ranges from altering plant cellular metabolic pathways and signaling cascades, RNA silencing, anti-microbial inhibition, and interfering with recognition machinery. The importance of understanding effector function has given rise to a new area of research termed effectoromics, which in this review refers to high-throughput studies to elucidate the function of a large number of candidate effector genes. Effectoromics research has led to the identification of a number of effectors with redundant function, indicating that pathogenic fungi and oomycetes contain effectors that are individually dispensable but functionally redundant that act synergistically to promote disease.}, number={2}, journal={FUNGAL BIOLOGY REVIEWS}, author={Sharpee, William C. and Dean, Ralph A.}, year={2016}, month={Jun}, pages={62–73} }
 @article{sharpee_oh_yi_franck_eyre_okagaki_valent_dean_2017, title={Identification and characterization of suppressors of plant cell death (SPD) effectors from Magnaporthe oryzae}, volume={18}, ISSN={["1364-3703"]}, DOI={10.1111/mpp.12449}, abstractNote={SummaryPhytopathogenic microorganisms, including the fungal pathogen Magnaporthe oryzae, secrete a myriad of effector proteins to facilitate infection. Utilizing the transient expression of candidate effectors in the leaves of the model plant Nicotiana benthamiana, we identified 11 suppressors of plant cell death (SPD) effectors from M. oryzae that were able to block the host cell death reaction induced by Nep1. Ten of these 11 were also able to suppress BAX‐mediated plant cell death. Five of the 11 SPD genes have been identified previously as either essential for the pathogenicity of M. oryzae, secreted into the plant during disease development, or as suppressors or homologues of other characterized suppressors. In addition, of the remaining six, we showed that SPD8 (previously identified as BAS162) was localized to the rice cytoplasm in invaded and surrounding uninvaded cells during biotrophic invasion. Sequence analysis of the 11 SPD genes across 43 re‐sequenced M. oryzae genomes revealed that SPD2, SPD4 and SPD7 have nucleotide polymorphisms amongst the isolates. SPD4 exhibited the highest level of nucleotide diversity of any currently known effector from M. oryzae in addition to the presence/absence polymorphisms, suggesting that this gene is potentially undergoing selection to avoid recognition by the host. Taken together, we have identified a series of effectors, some of which were previously unknown or whose function was unknown, that probably act at different stages of the infection process and contribute to the virulence of M. oryzae.}, number={6}, journal={MOLECULAR PLANT PATHOLOGY}, author={Sharpee, William and Oh, Yeonyee and Yi, Mihwa and Franck, William and Eyre, Alex and Okagaki, Laura H. and Valent, Barbara and Dean, Ralph A.}, year={2017}, month={Aug}, pages={850–863} }