@article{Luo2025, 
author = {Zhen Luo and Shuangqing Li and Muhammad Zain Ul Arifeen and Fei-xue Fu and Huayang Gao and Taoran Sun and Lingmei Liu and Xumei Sun and Xinwei Wang and Hai-Bo Jiang},
title = {Physiological and molecular evidence for phycobilisome degradation in maintaining carbon and nitrogen balance of cyanobacteria},
year = {2025},
journal = {Marine Life Science & Technology},
volume = {7},
number = {2},
pages = {218-230},
keywords = {Cyanobacteria, NblA, CCM, Gene knockout, Carbon/nitrogen balance},
url = {https://www.sciopen.com/article/10.1007/s42995-025-00290-0},
doi = {10.1007/s42995-025-00290-0},
abstract = {Phycobilisomes (PBS), the primary light-harvesting complexes in cyanobacteria, are degraded under nitrogen starvation to provide nitrogen for cell growth. This study reveals that carbon supply is a critical prerequisite for PBS degradation under nitrogen deficiency in Synechococcus sp. PCC 7002. Even under nitrogen-deficient conditions, PBS degradation is inhibited in the absence of sufficient carbon. We demonstrate that both the nblAB-mediated PBS-degradation pathway and the ccmLMNK operon-mediated CO2-concentrating mechanism are essential for PBS degradation. Furthermore, our findings highlight the critical role of PBS degradation in cyanobacterial adaptation to high C/N conditions. Mutant strains (Mut-nblA and Mut-nblB) deficient in PBS degradation exhibited impaired adaptation to high C/N conditions, as evidenced by their inability to thrive in high NaHCO3 (nitrogen-free) or CO2 (low-nitrogen) environments. While these mutants displayed a greener phenotype under high C/N conditions compared to the wild type, they exhibited extensive cellular damage, and significant downregulation of photosynthesis-related genes. These results provide novel insights into the carbon-dependent regulation of PBS degradation and its essential role in cyanobacterial C/N balance, highlighting its significance for their adaptation to fluctuating environmental conditions.}
}