The current study was undertaken to elucidate the impact of the herbicide pretilachlor (3 µg ml⁻¹ and 6 µg ml⁻¹) on cyanobacteria, Nostoc muscorum ATCC 27893 and Anabaena sp. PCC 7120 under three levels of photoacclimatization (suboptimum, 25 µmol photon m⁻² s⁻¹; optimum, 75 µmol photon m⁻² s⁻¹; and supra-optimum, 225 µmol photon m⁻² s⁻¹) by analyzing certain physiological (biomass accumulation, photosynthesis, Chl a fluorescence and respiration) and biochemical parameters (photosynthetic pigments‒ chlorophyll a, carotenoids and phycocyanin; reactive oxygen species‒ O₂^•¯, H₂O₂, lipid peroxidation; antioxidant system‒ superoxide dismutase, peroxidise, catalase and glutathione-S-transferase). The light conditioning played the most prominent role in deciding the extent of herbicide toxicity on both the tested cyanobacteria as the maximum toxicity was observed in suboptimum light acclimatized cyanobacterial cells corroborated by the least growth in the same cells. The impact of pretilachlor treatment on photosystem II photochemistry viz. φP₀, Ѱ₀, φE₀, PI_ABS, ABS/RC, TR₀/RC, ET₀/RC and DI₀/RC was also altered by light acclimatization. The percent rise in oxidative stress markers (SOR and H₂O₂) and consequent lipid peroxidation (MDA equivalents) were also highest in suboptimum light acclimatized cells exposed to pretilachlor which could not be prospered with compatible antioxidant performance. Conversely, supra-optimum light acclimatized cells of both the cyanobacteria was found to accelerate the activities of all the studied enzymes and thus able to counterbalance the pretilachlor toxicity and supported the healthier growth.

目前研究的目的是阐明除草剂丙草胺的影响（3微克毫升^-1和6微克毫升^-1）上蓝藻，发菜muscorum ATCC 27893和鱼腥藻。PCC 7120在三个水平的光适应下（亚最佳，25 µmol光子m ^-2 s ^-1；最佳，75 µmol光子m ^-2 s ^-1；和超最佳，225 µmol光子m ^-2 s ^-1）通过分析某些生理（生物量积累，光合作用，Chl a荧光和呼吸作用）和生化参数（光合色素‒叶绿素a，类胡萝卜素和藻蓝蛋白；活性氧O ₂ ^•，H ₂ O ₂，脂质过氧化；抗氧化剂系统：超氧化物歧化酶，过氧化物，过氧化氢酶和谷胱甘肽-S-转移酶）。光照条件在决定除草剂对两种被测蓝细菌的毒性程度方面起着最突出的作用，因为在亚最佳光适应的蓝细菌细胞中观察到了最大毒性，而蓝藻细胞在同一细胞中的生长最少，从而证实了这种毒性。丙草胺处理对光系统II光化学的影响。φP ₀，Ѱ ₀，φE ₀，PI _ABS，ABS / RC，TR ₀ / RC，ET ₀/ RC和DI ₀ / RC也会因光照适应而发生变化。氧化应激标志物（SOR和H ₂ O ₂）的增加百分比以及随之产生的脂质过氧化（MDA当量）在暴露于丙草胺的亚最佳光适应细胞中也最高，而抗氧化剂性能不佳。相反，发现这两个蓝细菌的超最佳光适应细胞可以加速所有研究的酶的活性，从而能够抵消丙草胺的毒性并支持更健康的生长。