Laboratory of Photobiology and Molecular Microbiology, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
Taurmed Technologies Pvt Ltd., 304, Pearl's Business Park, Netaji Subhash Place, New Delhi 110034, India.
Int J Mol Sci. 2023 Aug 3;24(15):12381. doi: 10.3390/ijms241512381.
Ultraviolet radiation (UVR) tends to damage key cellular machinery. Cells may adapt by developing several defence mechanisms as a response to such damage; otherwise, their destiny is cell death. Since cyanobacteria are primary biotic components and also important biomass producers, any drastic effects caused by UVR may imbalance the entire ecosystem. Cyanobacteria are exposed to UVR in their natural habitats. This exposure can cause oxidative stress which affects cellular morphology and vital processes such as cell growth and differentiation, pigmentation, photosynthesis, nitrogen metabolism, and enzyme activity, as well as alterations in the native structure of biomolecules such as proteins and DNA. The high resilience and several mitigation strategies adopted by a cyanobacterial community in the face of UV stress are attributed to the activation of several photo/dark repair mechanisms, avoidance, scavenging, screening, antioxidant systems, and the biosynthesis of UV photoprotectants, such as mycosporine-like amino acids (MAAs), scytonemin (Scy), carotenoids, and polyamines. This knowledge can be used to develop new strategies for protecting other organisms from the harmful effects of UVR. The review critically reports the latest updates on various resilience and defence mechanisms employed by cyanobacteria to withstand UV-stressed environments. In addition, recent developments in the field of the molecular biology of UV-absorbing compounds such as mycosporine-like amino acids and scytonemin and the possible role of programmed cell death, signal perception, and transduction under UVR stress are discussed.
紫外线辐射（UVR）往往会破坏关键的细胞机制。细胞可能会通过发展几种防御机制来适应这种损伤；否则，它们的命运就是细胞死亡。由于蓝藻是主要的生物成分，也是重要的生物量生产者，任何由 UVR 引起的剧烈影响都可能使整个生态系统失去平衡。蓝藻在其自然栖息地暴露于 UVR 下。这种暴露会导致氧化应激，从而影响细胞形态和重要过程，如细胞生长和分化、色素沉着、光合作用、氮代谢和酶活性，以及蛋白质和 DNA 等生物分子的天然结构的改变。由于蓝藻群落面对 UV 压力时激活了几种光/暗修复机制、避免、清除、筛选、抗氧化系统以及合成 UV 光保护剂，如菌氨酸类似物（MAAs）、Scy 等，其具有很高的弹性和几种缓解策略。 （Scytonemin）、类胡萝卜素和多胺。这些知识可用于开发新策略来保护其他生物体免受 UVR 的有害影响。本综述批判性地报告了蓝藻用于耐受 UV 胁迫环境的各种弹性和防御机制的最新进展。此外，还讨论了分子生物学领域中紫外线吸收化合物（如菌氨酸类似物和 Scy）的最新进展以及程序细胞死亡、信号感知和转导在 UVR 应激下的可能作用。
