The unparalleled performance of Chlorella ohadii under irradiances of twice full sunlight underlines the gaps in our understanding of how the photosynthetic machinery operates, and what sets its upper functional limit. Rather than succumbing to photodamage under extreme irradiance, unique features of photosystem II function allow C. ohadii to maintain high rates of photosynthesis and growth, accompanied by major changes in composition and cellular structure. This remarkable resilience allowed us to investigate the systems response of photosynthesis and growth to extreme illumination in a metabolically active cell. Using redox proteomics, transcriptomics, metabolomics and lipidomics, we explored the cellular mechanisms that promote dissipation of excess redox energy, protein S-glutathionylation, inorganic carbon concentration, lipid and starch accumulation, and thylakoid stacking. C. ohadii possesses a readily available capacity to utilize a sudden excess of reducing power and carbon for growth and reserve formation, and post-translational redox regulation plays a pivotal role in this rapid response. Frequently the response in C. ohadii deviated from that of model species, reflecting its life history in desert sand crusts. Comparative global and case-specific analyses provided insights into the potential evolutionary role of effective reductant utilization in this extreme resistance of C. ohadii to extreme irradiation.

奥哈迪小球藻在两倍全日照的辐照下无与伦比的表现突显了我们对光合作用机制如何运作以及设定其功能上限的理解方面的差距。与其在极端辐照下屈服于光损伤，光系统 II 功能的独特特征允许C. ohadii保持高速率的光合作用和生长，伴随着成分和细胞结构的重大变化。这种非凡的弹性使我们能够研究光合作用和生长对代谢活跃细胞中极端光照的系统响应。使用氧化还原蛋白质组学、转录组学、代谢组学和脂质组学，我们探索了促进多余氧化还原能量消散、蛋白质 S-谷胱甘肽化、无机碳浓度、脂质和淀粉积累以及类囊体堆积的细胞机制。C. ohadii具有随时可用的能力，可以利用突然过量的还原力和碳来进行生长和储备形成，而翻译后氧化还原调节在这种快速反应中起着关键作用。经常回复C. ohadii与模式物种的差异，反映了其在沙漠沙壳中的生活史。比较全局和具体案例分析提供了对有效还原剂利用在C. ohadii对极端辐照的极端抵抗中的潜在进化作用的见解。