Effect of long-term desiccation on the marine green algae <i>Prasiola delicata </i>and <i>Rosenvingiella constricta</i> (Chlorophyta, Prasiolales)
This paper discusses desiccation tolerance and ability to recover and successfully reproduce after 3-4 years of drying in the marine supra-tidal green algae Prasiola delicata and Rosenvingiella constricta from Kamchatka. We collected 3 types of plants with different morphologies belonging to 2 species, such as P. delicata (small linear blades) and R. constricta (multiseriate filaments with constrictions and hood-like small uniseriate blades, hereafter called R. constricta morphotype “constricta” and morphotype “prasiola”, respectively). Collected samples were dried in silica gel to the state when they lost almost 100% of intracellular water and became fragile and crisp. Thereafter, they were held at 4°С condition while being inside silica gel-filled plastic tubes. Rehydration experiments showed that P. delicata and R. constricta morphotype “constricta” could revive in seawater after 4 years of desiccation and began reproduction by autospores, whereas hood-like blades of R. constricta morphotype “prasiola” were able to survive 3 years of desiccation. Alive cell staining with fluorescein diacetate (FDA) showed that after rehydration, cells required 4-12 days to recover metabolic processes in the cytoplasm. Reproduction by autospores was observed in all rehydrated plants, usually starting from the margins of thalli and later covering almost the entire plants’ surface. Therefore, species P. delicata and R. constricta, including both of its morphotypes, should be regarded as orgamisms capable of extreme desiccation, since they remain viable for at least 3-4 yeаrs after loosing almost 100% of intracellular water.