Oomycete genomics. The oomycetes which include the Phytophthora and Pythium species, are amongst the most destructive and economically important plant pathogens around the world. Genomic analysis has revealed the importance of horizontal gene transfers from the ancestral green algal endosymbiont, and additional gene acquisition events from archaea and bacteria in shaping these genomes. We are particularly interested in the functional analysis of novel metabolic proteins and membrane transporters.
Polyamine transport. In plants, changes in cellular levels of polyamines are strongly correlated with the response to stresses such as drought, salinity, temperature fluctuations, and developmental processes such as root growth, and floral initiation. The goal of our research is to understand how polyamine synthesis and transport are regulated to enable plants to respond optimally to environmental signals. We have demonstrated that alterations in the expression of key polyamine transporters have striking effects on plant development and structure, a novel way of demonstrating the key role of polyamines as signaling compounds. Our recent research has identified two new routes for putrescine synthesis in the model plant A. thaliana.
Ariyaratne, M , Ge, L, Morris, PF. Characterization of membrane transporters by heterologous expression in E. Coli and production of membrane vesicles. JOVE 2020 (in press).
Lou YR, Ahmed S, Yan J, Adio AM, Powell HM, Morris PF, Jander G. Arabidopsis ADC1 functions as an N(δ) -acetylornithine decarboxylase. J Integr Plant Biol. 2019 May 13. doi: 10.1111/jipb.12821. [Epub ahead of print] PubMed PMID: 31081586.
Song W, Yang C, Zhu C, Morris PF, Zhang X. Crystal structure and expression patterns of prolyl 4-hydroxylases from Phytophthora capsici. Biochem Biophys Res Commun. 2019 Jan 22;508(4):1011-1017. doi: 10.1016/j.bbrc.2018.12.022. Epub 2018 Dec 11. PubMed PMID: 30551874.
Wagner A, Norris S, Chatterjee P, Morris PF, Wildschutte H. Aquatic Pseudomonads Inhibit Oomycete Plant Pathogens of Glycine max. Front Microbiol. 2018 May 29;9:1007. doi: 10.3389/fmicb.2018.01007. eCollection 2018. PubMed PMID: 29896163; PubMed Central PMCID: PMC5986895.
Patel J, Ariyaratne M, Ahmed S, Ge L, Phuntumart V, Kalinoski A, Morris PF. Dual functioning of plant arginases provides a third route for putrescine synthesis. Plant Sci. 2017 Sep;262:62-73. doi: 10.1016/j.plantsci.2017.05.011. Epub 2017 Jun 1. PubMed PMID: 28716421.
Ahmed S, Ariyaratne M, Patel J, Howard AE, Kalinoski A, Phuntumart V, Morris PF. Altered expression of polyamine transporters reveals a role for spermidine in the timing of flowering and other developmental response pathways. Plant Sci. 2017 May;258:146-155. doi: 10.1016/j.plantsci.2016.12.002. Epub 2016 Dec 24. PubMed PMID: 28330558.
Fu L, Zhu C, Ding X, Yang X, Morris PF, Tyler BM, Zhang X. Characterization of cell-death-inducing members of the pectate lyase gene family in phytophthora capsici and their contributions to infection of pepper. Mol Plant Microbe Interact. 2015 Jul;28(7):766-75. doi: 10.1094/MPMI-11-14-0352-R. Epub 2015 Jul 8. PubMed PMID: 25775270.
Mulangi V, Chibucos MC, Phuntumart V, Morris PF. Kinetic and phylogenetic analysis of plant polyamine uptake transporters. Planta. 2012 Oct;236(4):1261-73. Epub 2012 Jun 19. PubMed PMID: 22711282.