Su Yixi, Chen Jiwei, Hu Jingyan, Qian Cheng, Ma Jiahao, Brynjolfsson Sigurður, Fu Weiqi
Ocean College, Zhejiang University, Zhoushan, Zhejiang 316021, China.
Center for Systems Biology and Faculty of Industrial Engineering, School of Engineering and Natural Sciences, University of Iceland, 101 Reykjavík, Iceland.
iScience. 2024 Jul 10;27(8):110482. doi: 10.1016/j.isci.2024.110482. eCollection 2024 Aug 16.
A major obstacle to exploiting industrial flue gas for microalgae cultivation is the unfavorable acidic environment. We previously identified three upregulated genes in the low-pH-adapted model diatom : ferredoxin (PtFDX), cation/proton antiporter (PtCPA), and HCO transporter (PtSCL4-2). Here, we individually overexpressed these genes in to investigate their respective roles in resisting acidic stress (pH 5.0). The genetic modifications enabled positive growths of transgenic strains under acidic stress that completely inhibited the growth of the wild-type strain. Physiological studies indicated improved photosynthesis and reduced oxidative stress in the transgenic strains. Transcriptomes of the PtCPA- and PtSCL4-2-overexpressing transgenics showed widespread upregulation of various transmembrane transporters, which could help counteract excessive external protons. This work highlights ion/electron carrier genes' role in enhancing diatom resistance to acidic stress, providing insights into phytoplankton adaptation to ocean acidification and a strategy for biological carbon capture and industrial flue gas CO utilization.
利用工业烟道气进行微藻培养的一个主要障碍是不利的酸性环境。我们之前在适应低pH值的模式硅藻中鉴定出三个上调基因：铁氧化还原蛋白（PtFDX）、阳离子/质子反向转运蛋白（PtCPA）和HCO转运蛋白（PtSCL4-2）。在此，我们在[具体对象未提及]中分别过表达这些基因，以研究它们在抵抗酸性胁迫（pH 5.0）中的各自作用。基因改造使转基因菌株在酸性胁迫下能够正向生长，而这种酸性胁迫完全抑制了野生型菌株的生长。生理学研究表明，转基因菌株的光合作用得到改善，氧化应激降低。过表达PtCPA和PtSCL4-2的转基因植株的转录组显示，各种跨膜转运蛋白广泛上调，这有助于抵消过量的外部质子。这项工作突出了离子/电子载体基因在增强硅藻对酸性胁迫抗性中的作用，为浮游植物适应海洋酸化提供了见解，并为生物碳捕获和工业烟道气CO利用提供了策略。
