Mother cells enlarged with starch accumulation produce daughter colonies with increased cell numbers in the colonial green alga Pediastrum duplex ( Chlorophyceae, Chlorophyta )
Year: 2026
Type: article
Abstract: SUMMARY Spring algal blooms are characterized by the rapid expansion of phytoplankton populations under favorable environmental conditions, yet the intracellular mechanisms that enable this rapid proliferation remain poorly understood. In this study, using the colonial green alga Pediastrum duplex , we found that mother cells enlarged with starch accumulation under cold conditions in the light promote an increase in the number of cells per daughter colony under subsequent warm conditions. At 11°C under light, the proliferation of P. duplex colonies was arrested. When the arrested cells were transferred to the optimal temperature (25°C), they rapidly resumed growth and preferentially formed new colonies with higher cell numbers. Microscopic analysis revealed that arrested cells cultured at 11°C enlarged and accumulated substantial amounts of starch. When we supplemented the culture medium with glucose at 25°C, we artificially induced starch accumulation and cell enlargement in P. duplex cells without low‐temperature treatment. The presence of enlarged mother cells containing starch led to the formation of daughter colonies with higher cell numbers than those derived from non‐enlarged mother cells lacking starch, suggesting that starch accumulation and/or enlargement of mother cells contribute to the development of daughter colonies. These findings suggest that under low‐temperature conditions in the light (i.e., in winter), P. duplex enters a preparatory state characterized by growth arrest, cell enlargement, and starch accumulation and that upon return to favorable conditions (i.e., in spring), the enlarged mother cells containing starch, together with other physiological changes induced by low temperature and light exposure, support additional rounds of cell division, resulting in daughter colonies with more cells and rapid population expansion. This intracellular mechanism may contribute to the rapid expansion of algal populations during spring algal blooms, highlighting the importance of physiological preconditioning for bloom dynamics.
Source: Phycological Research
DOI: 10.1111/pre.70061
Authors: Akari Masaki, Tomoko Shinomura, Yutaka Kodama
Institutions: Utsunomiya University, Teikyo University
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,800
OpenAlex ID: W7225833229