Abstract：
Ginkgo biloba leaf extract (GBE) can effectively treat bloom-forming freshwater algae. However, there is limited information about the underlying suppression mechanism of the marine bloom-forming Prorocentrum donghaiense-the most dominant algal bloom species in the East China Sea. We investigated the effect of GBE on P. donghaiense in terms of its response to photosynthesis at the molecular/omic level. In total, 93,743 unigenes were annotated using six functional databases. Furthermore, 67,203 differentially expressed genes (DEGs) were identified in algae treated with 1.8 g∙L-1 GBE. Among these DEGs, we identified the genes involved in photosynthesis. PsbA, PsbB and PsbD in photosystem II, PsaA in photosystem I, and PetB and PetD in the cytochrome b6/f complex were downregulated. Other related genes, such as PsaC, PsaE, and PsaF in photosystem I; PetA in the cytochrome b6/f complex; and atpA, atpD, atpH, atpG, and atpE in the F-type H+-ATPase were upregulated. These results suggest that the structure and activity of the complexes were destroyed by GBE, thereby inhibiting the electron flow between the primary and secondary quinone electron acceptors, primary quinone electron acceptor, and oxygen-evolving complex in the PSII complex, and interrupting the electron flow between PSII and PSI, ultimately leading to a decline in algal cell photosynthesis. These findings provide a basis for understanding the molecular mechanisms underlying P. donghaiense exposure to GBE and a theoretical basis for the prevention and control of harmful algal blooms.
摘要：
银杏叶提取物（GBE）可以有效地处理水华形成的淡水藻类。然而,关于东海最主要的藻类水华物种东海原中心的潜在抑制机制的信息有限。我们在分子/组学水平上研究了GBE对P.donghaiense的影响。总的来说,使用六个功能数据库对93,743个单基因进行了注释。此外，在用1.8g·L-1GBE处理的藻类中鉴定出67,203个差异表达基因（DEGs）。在这些DEG中,我们确定了参与光合作用的基因。PsbA,光系统II中的PsbB和PsbD，光系统I中的PsaA，细胞色素b6/f复合物中的PetB和PetD下调。其他相关基因,比如PsaC，PsaE,光系统I中的PsaF；细胞色素b6/f复合物中的PetA；和atpA，atpD,atpH值,atpG,F型H+-ATP酶中的atpE上调。这些结果表明，GBE破坏了复合物的结构和活性，从而抑制初级和次级醌电子受体之间的电子流，伯醌电子受体，和PSII复合体中的放氧复合体，中断PSII和PSI之间的电子流，最终导致藻类细胞光合作用下降。这些发现为理解东海假单胞菌暴露于GBE的分子机制提供了基础，并为预防和控制有害藻华提供了理论基础。
