Photosynthetic properties of the protoplasts from Bryopsis hypnoides Lamouroux. during the early regeneration process

Abstract

The scanning electronic microphotograph (SEM), photosynthetic oxygen evolution rate and excitation spectra at liquid nitrogen temperature (77 K) of the protoplasts from Bryopsis hypnoides were determined at the early regeneration period (12 h). SEM revealed an existence of the tight aggregation; cell membrane and wall were about 10 min, 6 and 12 h respectively, after the culture. Oxygen evolution rate decreased slowly during the whole process and a minus value appeared at 6 h. Peaks originated from photosystem II (PS II) and photosystem I (PS I) apparently shifted to shorter wavelength during the regeneration process in the excitation spectra. No peak from PS I was determined until in the spectrum of 12 h, which was excited by the wavelength of 436 nm; while the peak from PS I appeared in the spectrum of extruded protoplast excited by the wavelength of 660 nm and strengthened during the rest of the regeneration process. Key words: Photosynthetic oxygen evolution rate, absorbance spectra, excitation spectra