Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
Mar Biol
2008 Jan 01;1541:109-116. doi: 10.1007/s00227-008-0904-4.
Show Gene links
Show Anatomy links
pH effect on the susceptibility to parasitoid infection in the marine diatom Coscinodiscus spp. (Bacillariophyceae).
Kühn SF
,
Köhler-Rink S
.
???displayArticle.abstract???
The pH on the frustule of individual cells of the marine centric diatoms Coscinodiscus granii and Coscinodiscus wailesii (Bacillariophyceae) was measured with pH microsensors in culture media with increasing pH values of 8.04, 8.14, and 8.22, respectively. In 85-96% of the C.granii cells the pH on the frustule was up to 0.4 units higher than that of the medium, reaching a maximum pH 8.95. Only in 2-3% the surface pH exceeded that of the medium by up to 0.7 pH units. These results strongly suggest that diatoms in batch cultures differ, at least temporarily, in their individual photosynthetic activities. Infection experiments with the parasitoid nanoflagellate Pirsonia diadema (Stramenopile) showed that flagellates failed to infect when the culture pH was 8.8 and above. pH measurements on freshly infected C. granii showed that the prevalence of infection was higher in tendency on diatoms with low surface pH. Application of these results to parasitoid-diatom interactions in natural waters suggests that within phytoplankton populations a strong photosynthetic activity might prevent diatom cells temporarily from infection by pH-sensitive parasitoids.
Fig. 1. Experimental set-up of microsensor experiments. Diatoms were placed in small chambers on agar. Photographs show a âdoubleâ cell of Coscinodiscus granii (left), a âsingleâ C. granii cell infected by Pirsonia diadema (middle) and C. wailesii (right)
Fig. 2. Development of pH in seawater adjusted to initial pH values varying from 6.8 to 9.5
Fig. 3. Development of pH in Coscinodiscus wailesii cultures adjusted to initial pH values varying from 6.8 to 8.7
Fig. 4.
Coscinodiscus granii batch cultures infected by Pirsonia diadema: development of pH (open square) and percentage of infected diatoms (filled circle) in single replica. Diatom cultures were inoculated with P. diadema on Day 3 (a, c) and Day 4 (b)
Fig. 5. Surface pH of Coscinodiscus granii cells at different pH values of ambient seawater, measured with pH microsensors
Fig. 6. The pH of the F/2 medium varied between 7.98 and 8.29. Measurements at the ranges pH 7.98â8.09, 8.10â8.19 and 8.20â8.29 were grouped together. Mean values (±SD) of ambient seawater (F/2) pH and corresponding pH on the frustule of Coscinodiscus granii are given
Fig. 7. pH on frustules of Coscinodiscus granii single cells and dividing (âdoubleâ) cells at different pH of F/2. The number of measurements (n) is given at the base of the bar
Fig. 8. pH on frustule of infected and non-infected Coscinodiscus granii cells at different pH of F/2. The number of measurements (n) is given at the base of the bar
Fig. 9. Microsensor measurements of vacuolar pH of Coscinodiscus wailesii at different ambient pH
Boklage,
Sex ratio unaffected by parental age gap.
1997, Pubmed
Boklage,
Sex ratio unaffected by parental age gap.
1997,
Pubmed
GUILLARD,
Studies of marine planktonic diatoms. I. Cyclotella nana Hustedt, and Detonula confervacea (cleve) Gran.
1962,
Pubmed
Kühn,
Photosynthetic oscillation in individual cells of the marine diatom Coscinodiscus wailesii (Bacillariophyceae) revealed by microsensor measurements.
2008,
Pubmed
McClintock,
Active, Irreversible Accumulation of Extreme Levels of H(2)SO(4) in the Brown Alga, Desmarestia.
1982,
Pubmed