@article{jin_mccorkle_cornish_carbone_lewis_shew_2022, title={Adaptation of Phytophthora nicotianae to Multiple Sources of Partial Resistance in Tobacco}, volume={106}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-06-21-1241-RE}, abstractNote={ Host resistance is an important tool in the management of black shank disease of tobacco. Race development leads to rapid loss of single-gene resistance, but the adaptation by Phytophthora nicotianae to sources of partial resistance from Beinhart 1000, Florida 301, and the Wz gene region introgressed from Nicotiana rustica is poorly characterized. In greenhouse environments, host genotypes with quantitative trait loci (QTLs) conferring resistance from multiple sources were initially inoculated with an aggressive isolate of race 0 or race 1 of P. nicotianae. The most aggressive isolate was selected after each of six host generations to inoculate the next generation of plants. The race 0 isolate demonstrated a continuous gradual increase in disease severity and percentage root rot on all sources of resistance except the genotype K 326 Wz/–, where a large increase in both was observed between generations 2 and 3. Adaptation by the race 0 isolate on Beinhart 1000 represents the first report of adaptation to this genotype by P. nicotianae. The race 1 isolate did not exhibit significant increases in aggressiveness over generations but exhibited a large increase in aggressiveness on K 326 Wz/– between generations 3 and 4. Molecular characterization of isolates recovered during selection was completed via double digest restriction-site associated DNA sequencing, but no polymorphisms were associated with the observed changes in aggressiveness. The rapid adaptation to Wz resistance and the gradual adaptation to other QTLs highlights the need to study the nature of Wz resistance and to conduct field studies on the efficacy of resistance gene rotation for disease management. }, number={3}, journal={PLANT DISEASE}, author={Jin, Jing and McCorkle, Kestrel L. and Cornish, Vicki and Carbone, Ignazio and Lewis, Ramsey S. and Shew, H. David}, year={2022}, month={Mar}, pages={906–917} }
 @article{jin_shew_2022, title={Impacts of Continued Exposure to a Susceptible Host Genotype on Aggressiveness of Phytophthora nicotianae Isolates Adapted to Multiple Sources of Partial Resistance}, volume={106}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-09-20-1972-RE}, abstractNote={ Pathogen adaptation can threaten the durability of partial resistance. Mixed plantings of susceptible and partially resistant varieties may prolong the effectiveness of partial resistance, but little is known about how continued exposure to a susceptible genotype can change the aggressiveness of pathogen isolates adapted to a source of partial resistance. The objective of this study was to examine the effects of continued exposure to a highly susceptible tobacco genotype on isolates of Phytophthora nicotianae that had been adapted to partial resistance. Isolates of P. nicotianae previously adapted to two sources of partial resistance were continually exposed to either the original host of adaptation or a susceptible host. After six generations of host exposure, isolates obtained from the partially resistant and the susceptible hosts were compared for their aggressiveness on the resistant host and for differences in expression of genes associated with pathogenicity and aggressiveness. Results suggested that exposure to the susceptible tobacco genotype reduced aggressiveness of isolates adapted to partial resistance in K 326 Wz/– but not of isolates adapted to partial resistance in Fla 301. Quantification of pathogenicity-associated gene expression using qRT-PCR suggested the rapid change in aggressiveness of isolates adapted to Wz-sourced partial resistance may have resulted from modification in gene expression in multiple genes. }, number={2}, journal={PLANT DISEASE}, author={Jin, Jing and Shew, H. David}, year={2022}, month={Feb}, pages={373–381} }
 @article{jin_shew_2021, title={Components of Aggressiveness in Phytophthora nicotianae During Adaptation to Multiple Sources of Partial Resistance in Tobacco}, volume={105}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-09-20-1929-RE}, abstractNote={ Black shank is a devastating disease of tobacco caused by Phytophthora nicotianae. Host resistance has been an integral part of black shank management but after the loss of Php single-gene resistance following its widespread deployment in the 1990s, growers have relied on varieties with varying levels of partial resistance. Partial resistance is effective in suppressing disease, but continued exposure can result in an increase in pathogen aggressiveness that threatens durability of the resistance to P. nicotianae. Aggressiveness components in P. nicotianae were characterized following adaptation on two sources of partial resistance, Fla 301 and the Wz genomic region from Nicotiana rustica. An aggressive isolate of the two major races of P. nicotianae, race 0 and race 1, was adapted for either one/two or five/six generations on the two resistance sources, giving four sets of isolates based on race, number of generations of adaptation, and source of resistance. Across the four sets of isolates, adapted isolates infected higher proportions of tobacco root tips, produced more sporangia per infected root tip, and caused larger lesions than their respective nonadapted isolates of the same race and from the same resistance source. Adapted isolates also produced more aggressive zoospore progeny than the nonadapted isolates. Adaptation to partial resistance involves multiple aggressiveness components and results in the increased aggressiveness observed for P. nicotianae. These results improve our knowledge on the nature of P. nicotianae adaptation to partial resistance in tobacco and indicate that different resistance sources are likely to select for similar aggressiveness components in the pathogen. }, number={7}, journal={PLANT DISEASE}, author={Jin, Jing and Shew, H. David}, year={2021}, month={Jul}, pages={1960–1966} }
 @article{shi_jin_nifong_shew_lewis_2021, title={Homoeologous chromosome exchange explains the creation of a QTL affecting soil-borne pathogen resistance in tobacco}, ISSN={["1467-7652"]}, DOI={10.1111/pbi.13693}, abstractNote={Summary}, journal={PLANT BIOTECHNOLOGY JOURNAL}, author={Shi, Rui and Jin, Jing and Nifong, Jessica M. and Shew, David and Lewis, Ramsey S.}, year={2021}, month={Oct} }
 @article{jin_shi_lewis_shew_2021, title={RNAseq Reveals Differential Gene Expression Contributing to Phytophthora nicotianae Adaptation to Partial Resistance in Tobacco}, volume={11}, ISSN={["2073-4395"]}, DOI={10.3390/agronomy11040656}, abstractNote={Phytophthora nicotianae is a devastating oomycete plant pathogen with a wide host range. On tobacco, it causes black shank, a disease that can result in severe economic losses. Deployment of host resistance is one of the most effective means of controlling tobacco black shank, but adaptation to complete and partial resistance by P. nicotianae can limit the long-term effectiveness of the resistance. The molecular basis of adaptation to partial resistance is largely unknown. RNAseq was performed on two isolates of P. nicotianae (adapted to either the susceptible tobacco genotype Hicks or the partially resistant genotype K 326 Wz/Wz) to identify differentially expressed genes (DEGs) during their pathogenic interactions with K 326 Wz/Wz and Hicks. Approximately 69% of the up-regulated DEGs were associated with pathogenicity in the K 326 Wz/Wz-adapted isolate when sampled following infection of its adapted host K 326 Wz/Wz. Thirty-one percent of the up-regulated DEGs were associated with pathogenicity in the Hicks-adapted isolate on K 326 Wz/Wz. A broad spectrum of over-represented gene ontology (GO) terms were assigned to down-regulated genes in the Hicks-adapted isolate. In the host, a series of GO terms involved in nuclear biosynthesis processes were assigned to the down-regulated genes in K 326 Wz/Wz inoculated with K 326 Wz/Wz-adapted isolate. This study enhances our understanding of the molecular mechanisms of P. nicotianae adaptation to partial resistance in tobacco by elucidating how the pathogen recruits pathogenicity-associated genes that impact host biological activities.}, number={4}, journal={AGRONOMY-BASEL}, author={Jin, Jing and Shi, Rui and Lewis, Ramsey Steven and Shew, Howard David}, year={2021}, month={Apr} }