Aquatic Sciences Meeting, Albuquerque 2001

SS19 Revisiting Redfield: C:N:P Stoichiometry in Aquatic Ecosystems (Disciplinary Connections)

Date: Tuesday, February 13, 2001, Time: 12:00:00 PM

Location: Acoma/Zuni/Tesuque

Clasen, J, L, Arizona State University, Tempe, USA, clasen@asu.edu

Elser, J, J, Arizona State University, Tempe, USA, j.elser@asu.edu

DOES PHYTOPLANKTON NUTRIENT STATUS AFFECT VIRAL INFECTIONS?

Elemental composition influences phytoplankton quality for predators. We hypothesize that this is also true when the predator is a virus. Viral dynamics should reflect intracellular nutrient status of algae because they are obligate intracellular parasites. We tested this hypothesis using the exosymbiotic green algae Chlorella strain NC64a and its isolated virus, Paramecium bursaria Chlorella virus-1 (PBCV-1). Media phosphorous concentrations were manipulated to produce Chlorella cultures that had significantly different C:P ratios (high P cultures ~100; low P cultures ~ 400). There was no effect of algal P status on the ability of PBCV-1 to adsorb to Chlorella cells in either of the two culture types (p=.38). However, high P cultures had 83% more active viruses then low P cultures at 10 hours post infection. Additionally, the two cultures were significantly different (p=0.008) in their burst sizes (the number of new viruses produced per infected host cell). On average, high P Chlorella cultures had a burst size 12 times higher then low P cultures. Therefore, phytoplankton nutrient limitation has major effects on viral infections via decreased replication.

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Aquatic Sciences Meeting, Albuquerque 2001

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