Temperate infection in a canonically virulent virus-host system

Ben Knowles1, Juan A Bonachela2, Michael Behrenfeld3, Karen Grace Bondoc4, B. B. Cael5, Craig A Carlson6, Nicole Cieslik7, Benjamin Diaz8, Heidi L Fuchs9, Jason Graff3, Juris Grasis10, Kimberly Halsey3, Liti Haramaty11, Christopher Johns1, Frank Natale1, Jozef Iosif Nissimov1, Dr. Brittany Schieler, PhD12, Kimberlee Thamatrakoln13, Tron Frede Thingstad14, Selina Våge15, Clifford Evan Watkins16, Toby Kolohe Westberry3 and Kay D Bidle13, (1)Rutgers University New Brunswick, Marine and Coastal Sciences, New Brunswick, NJ, United States, (2)Rutgers University, Department of Ecology, Evolution, and Natural Resources, United States, (3)Oregon State University, Corvallis, OR, United States, (4)Rutgers University New Brunswick, Department of Marine and Coastal Sciences, New Brunswick, United States, (5)University of Hawaii, Department of Oceanography, Honolulu, United States, (6)University of California Santa Barbara, Marine Science Institute/Department of Ecology, Evolution and Marine Biology, Santa Barbara, CA, United States, (7)Rutgers University New Brunswick, New Brunswick, United States, (8)Rutgers University New Brunswick, Microbial Biology, New Brunswick, NJ, United States, (9)Rutgers University New Brunswick, New Brunswick, NJ, United States, (10)University of California Merced, Merced, United States, (11)Rutgers University, NJ, United States, (12)Rutgers University, Marine and Coastal Sciences, New Brunswick, NJ, United States, (13)Rutgers University, Marine and Coastal Sciences, New Brunswick, United States, (14)University of Bergen, Norway, (15)University of Bergen, Bergen, Norway, (16)Rutgers University, New Brunswick, NJ, United States
Abstract:
The cosmopolitan coccolithophore Emiliania huxleyi and its viruses form ostensibly virulent relationships, wherein host growth promotes viral predation, ultimately curtailing blooms. This traditional view is based on viral-mediated host mortality in high density laboratory cultures and mesocosms. We show that at environmentally-relevant host densities, this system is instead characterized by viral dynamics where viruses transition from long-term non-lethal temperate infection of healthy hosts (virus-host ‘Détente’) to lethal lytic stages as host cells become physiologically stressed (viral-mediated ‘Coup-de-Grâce’). Our findings support a new conceptual model of virus-mediated bloom formation and decline – governed by host physiology rather than by host-virus densities – that revises our understanding of algal virus infection in nature from short-term antagonism to long-term co-existence.