Action spectrum of mycosporine-like amino acid (MAA) induction in Prorocentrum micans under solar radiation

PETER R. RICHTER; HELBLING, E. W.; VILLAFAÑE, V. E.; DONAT P. HADER

Advances in life sciences

I.K. International Publishing House Pvt. Ltd.

Año: 2011; p. 441 - 449

The dinoflagellate Prorocentrum micans produces mycosporine-like amino acids upon UVexposure. To identify the most efficient UV wavelength range of MAA-induction in Prorocentrummicans a polychromatic action spectrum under solar radiation was determined. Initially identicalsamples were exposed to solar radiation in UV-transparent quartz tubes deployed at thesurface of a large water container for temperature control. Solar radiation was measuredwith an ELDONET filter radiometer and the wavelength resolution calculated with the STARprogram. The full UV wavelength range of the solar spectrum was consecutively decreasedby means of cut-off filters and the corresponding cellular MAA synthesis was determinedafter MeOH extraction, based on the cell number and cell size. The following cut-off filterswere applied (no filter: full sun, 295 nm, 305 nm, 320 nm, 345 nm, 360 nm and 400 nm). Tocalculate a polychromatic action spectrum the difference of the intracellular MAA concentrationsof two subsequent samples was divided by the corresponding difference in the radiationdose. Short UV-B is most effective for MAA induction, but considerably MAA induction canbe seen up to 320 nm. Longer UV wavelengths are increasingly less effective.