CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, Shandong, People's Republic of China.
Marine Ecology and Environmental Science Laboratory, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, Shandong, People's Republic of China.
Genetica. 2021 Feb;149(1):63-72. doi: 10.1007/s10709-020-00112-4. Epub 2021 Jan 15.
Ulva prolifera O.F. Müller (Ulvophyceae, Chlorophyta) is well known as a typical green-tide forming macroalga which has caused the world's largest macroalgal blooms in the Yellow Sea of China. In this study, two full-length γ-carbonic anhydrase (γ-CA) genes (UpγCA1 and UpγCA2) were cloned from U. prolifera. UpγCA1 has three conserved histidine residues, which act as an active site for binding a zinc metal ion. In UpγCA2, two of the three histidine residues were replaced by serine and arginine, respectively. The two γ-CA genes are clustered together with other γ-CAs in Chlorophyta with strong support value (100% bootstrap) in maximum likelihood (ML) phylogenetic tree. Quantitative real-time PCR (qRT-PCR) analysis showed that stressful environmental conditions markedly inhibited transcription levels of these two γ-CA genes. Low pH value (pH 7.5) significantly increased transcription level of UpγCA2 not UpγCA1 at 12 h, whereas high pH value (pH 8.5) significantly inhibited the transcription of these two γ-CA genes at 6 h. These findings enhanced our understanding on transcriptional regulation of γ-CA genes in response to environmental factors in U. prolifera.
石莼（Ulvophyceae，Chlorophyta）是一种典型的绿潮形成大型海藻，在中国黄海造成了世界上最大的大型海藻藻华。在这项研究中，从石莼中克隆了两个全长γ-碳酸酐酶（γ-CA）基因（UpγCA1 和 UpγCA2）。UpγCA1 具有三个保守的组氨酸残基，作为结合锌金属离子的活性位点。在 UpγCA2 中，三个组氨酸残基中的两个分别被丝氨酸和精氨酸取代。这两个 γ-CA 基因与藻类中的其他 γ-CAs 一起聚类，在最大似然（ML）系统发育树中具有 100%的支持值（bootstrap）。定量实时 PCR（qRT-PCR）分析表明，胁迫环境条件显著抑制了这两个 γ-CA 基因的转录水平。低 pH 值（pH 7.5）在 12 小时时显著增加了 UpγCA2 的转录水平，但在 6 小时时显著抑制了这两个 γ-CA 基因的转录。这些发现增强了我们对石莼中 γ-CA 基因对环境因素的转录调控的理解。
