Evidence for lysogeny and viral resistance in the cyanobacteriumPhormidium uncinatum

Bisen, Prakash S.; Audholia, Surabhi; Bhatnagar, Arun Kishore; Bagchi, Suvendra Nath

doi:10.1007/bf01568150

Cited by 7 publications

(2 citation statements)

References 11 publications

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“…More specifically, when Phormidium growth was severely P-limited (0.05 d -1 , i.e., 17% of its maximum growth rate), adsorption of viruses was 51% as compared to 21% at the highest host growth rate (0.6 d -1 , i.e., 83% of maximum growth rate). Little is known about the viral resistance mechanism of Phormidium , except that a P. uncinatum mutant strain was viral resistant due to the complete absence of viral adsorption (Bisen et al, 1986). Generally, adsorption of viruses depends on density (Murray and Jackson, 1992), as well as on host cell size, where larger host cells provide a greater surface area for contact (Hadas et al, 1997).…”

Section: Discussionmentioning

confidence: 99%

Cyanophage Propagation in the Freshwater Cyanobacterium Phormidium Is Constrained by Phosphorus Limitation and Enhanced by Elevated pCO2

et al. 2019

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Intensification of human activities has led to changes in the availabilities of CO 2 and nutrients in freshwater ecosystems, which may greatly alter the physiological status of phytoplankton. Viruses require hosts for their reproduction and shifts in phytoplankton host physiology through global environmental change may thus affect viral infections as well. Various studies have investigated the impacts of single environmental factors on phytoplankton virus propagation, yet little is known about the impacts of multiple factors, particularly in freshwater systems. We therefore tested the combined effects of phosphorus limitation and elevated p CO 2 on the propagation of a cyanophage infecting a freshwater cyanobacterium. To this end, we cultured Phormidium in P-limited chemostats under ambient (400 μatm) and elevated (800 μatm) p CO 2 at growth rates of 0.6, 0.3, and 0.05 d -1 . Host C:P ratios generally increased with strengthened P-limitation and with elevated p CO 2 . Upon host steady state conditions, virus growth characteristics were obtained in separate infection assays where hosts were infected by the double-stranded DNA cyanophage PP. Severe P-limitation (host growth 0.05 d -1 ) led to a 85% decrease in cyanophage production rate and a 73% decrease in burst size compared to the 0.6 d -1 grown P-limited cultures. Elevated p CO 2 induced a 96% increase in cyanophage production rate and a 57% increase in burst size, as well as an 85% shorter latent period as compared to ambient p CO 2 at the different host growth rates. In addition, elevated p CO 2 caused a decrease in the plaquing efficiency and an increase in the abortion percentage for the 0.05 d -1 P-limited treatment, while the plaquing efficiency increased for the 0.6 d -1 P-limited cultures. Together, our results demonstrate interactive effects of elevated p CO 2 and P-limitation on cyanophage propagation, and show that viral propagation is generally constrained by P-limitation but enhanced with elevated p CO 2 . Our findings indicate that global change will likely have a severe impact on virus growth characteristics and thereby on the control of cyanobacterial hosts in freshwater ecosystems.

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Section: Discussionmentioning

confidence: 99%

Cyanophage Propagation in the Freshwater Cyanobacterium Phormidium Is Constrained by Phosphorus Limitation and Enhanced by Elevated pCO2

et al. 2019

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“…Nevertheless, the concept of using cyanophages in the control of cyanobacteria had not received widespread attention up to that point. This is a natural phenomenon that occurs in phage biology , including with cyanophages (Bisen et al 1986). 1 and 2).…”

Section: Cyanophage Biocontrolmentioning

confidence: 99%