Fate of eyespot lipid globules after zoospore settlement in the green algaPleurastrum terrestreFritsch et John

The fate of eyespot lipid globules after zoospore settlement in the green alga Pleurastrum terrestre Fritsch et John was investigated in detail. After retraction of flagella the close association between the outer chloroplast envelope membrane and the plasmalemma in the eyespot region is lost. The intact eyespot plate (with approximately 60 eyespot globules) then starts to change position inside the chloroplast. While staying in a peripheral position below the chloroplast envelope membranes, the eyespot plate moves around half of the chloroplast to the cell interior, where it comes to lie close to a mitochondrion. Later the eyespot plate curves around into the chloroplast interior and single eyespot globules enter the pyrenoid matrix of the chloroplast to join the pyrenoglobules, which characterize the pyrenoid of this alga. It is suggested that by incorporation into the pyrenoid the eyespot globules add to the lipid store of the growing vegetative cell. During zoosporogenesis pyrenoglobules may be drawn from this store and transformed into eyespot lipid globules.