Location: Subtropical Horticulture ResearchTitle: Differential response of Phytophthora megakarya and Phytophthora palmivora to temperature stress
|ALI, SHAHIN - Us Forest Service (FS)|
|Sicher Jr, Richard|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/22/2017
Publication Date: 1/14/2018
Citation: Puig, A.S., Ali, S., Strem, M.D., Sicher Jr, R.C., Gutierrez, O.A., Bailey, B.A. 2017. Differential response of Phytophthora megakarya and Phytophthora palmivora to temperature stress. Meeting Abstract. San Diego, CA. January 13-17, 2018.
Technical Abstract: Phytophthora megakarya and Phytophthora palmivora cause black pod rot of cacao, one of the most economically significant diseases affecting this crop. They are closely related but differ in terms of aggressiveness and response to temperature. P. palmivora has a higher temperature maximum (34°C) than P. megakarya (30°C). In culture, P. megakarya lost viability after 3 days at 32°C while P. palmivora viability began decreasing after 3 days at 36°C. This study provides insight into the effects of temperature stress on these pathogens and the underlying resistance mechanisms by monitoring expression changes in genes involved in abiotic stress responses in other species. When exposed to heat, genes encoding heat shock proteins and chaperones were most commonly induced in both species. When inducible in P. megakarya, these genes were almost exclusively heat responsive, tending toward lower expression at cold temperatures. In P. palmivora these heat responsive genes also tended to be induced at low temperatures (9°C and 11°C). Although there were some temperature induced differences in metabolite profiles between the species, P. palmivora maintained higher metabolite pools overall than P. megakarya. Due to these differences between P. megakarya and P. palmivora, temperature is likely to influence epidemiology and the potential of these pathogens to spread to new areas.