PDF(Pubmed)
Abstract：
Zinc (Zn) is an essential trace element but can lead to water contamination and ecological deterioration when present in excessive amounts. Therefore, investigating the photosynthetic response of microalgae to Zn stress is of great significance. In this study, we assessed the photosynthetic responses of neutrophilic Chlamydomonas reinhardtii and acidophilic Chlamydomonas sp. 1710 to Zn exposure for 96 h. The specific growth rate (μ), chlorophyll-a (Chl-a) content, and chlorophyll fluorescence parameters were determined. The results demonstrated that Chlamydomonas sp. 1710 was much more tolerant to Zn than C. reinhardtii, with the half-maximal inhibitory concentration (IC50) values of 225.4 mg/L and 23.4 mg/L, respectively. The μ and Chl-a content of C. reinhardtii decreased in the presence of 15 mg/L Zn, whereas those of Chlamydomonas sp. 1710 were unaffected by as high as 100 mg/L Zn. Chlorophyll fluorescence parameters indicated that the regulation of energy dissipation, including non-photochemical quenching, played a crucial role in Zn stress resistance for both Chlamydomonas strains. However, in the case of C. reinhardtii, non-photochemical quenching was inhibited by 5 mg/L Zn in the first 48 h, whereas for Chlamydomonas sp. 1710, it remained unaffected under 100 mg/L Zn. Chlamydomonas sp. 1710 also exhibited a 20 times stronger capacity for regulating the electron transfer rate than C. reinhardtii under Zn stress. The light energy utilization efficiency (α) of Chlamydomonas sp. 1710 had the most highly non-linear correlation with μ, indicating the energy utilization and regulation process of Chlamydomonas sp. 1710 was well protected under Zn stress. Collectively, our findings demonstrate that the photosystem of Chlamydomonas sp. 1710 is much more resilient and tolerant than that of C. reinhardtii under Zn stress.
摘要：
锌（Zn）是一种必需的微量元素，但过量存在时会导致水污染和生态恶化。因此,研究微藻对Zn胁迫的光合响应具有重要意义。在这项研究中,我们评估了嗜中性衣藻和嗜酸性衣藻的光合反应。1710对Zn暴露96小时。比生长速率(μ)，叶绿素a（Chl-a）含量，并测定了叶绿素荧光参数。结果表明衣藻属。1710对锌的耐受性比莱茵硬石高得多，半最大抑制浓度（IC50）值为225.4mg/L和23.4mg/L，分别。在15mg/LZn存在下，莱茵衣原体的μ和Chl-a含量降低，而衣藻属。1710不受高达100mg/LZn的影响。叶绿素荧光参数表明，能量耗散的调节作用，包括非光化学猝灭，在两种衣藻菌株的锌胁迫抗性中起着至关重要的作用。然而,在C.Reinhardtii的案例中,在最初的48小时内，5mg/LZn抑制了非光化学猝灭，而对于衣藻。1710，在100mg/LZn下保持未受影响。衣藻。在Zn应力下，1710还显示出比C.reinhardtii强20倍的调节电子转移速率的能力。衣藻的光能利用效率（α）。1710与μ的非线性相关性最高，说明衣藻的能量利用和调节过程。1710在Zn胁迫下保护良好。总的来说，我们的发现表明衣藻的光系统。在Zn胁迫下，1710的弹性和耐受性要比莱茵C.reinhardtii好得多。
