Mechanistic insights into Ginkgo-nerolidol compound preparation against the bloom-forming dinoflagellate Prorocentrum donghaiense

Abstract

Prorocentrum donghaiense is a major bloom-forming species in the East China Sea and has severe adverse effects on marine ecosystems. To address this issue, the development of efficient and eco-friendly algal inhibitors is essential. However, research in this area remains limited. In this study, Ginkgo biloba extract (GB), nerolidol (NE), and a compound preparation (GN = GB + NE) were selected as algae-inhibiting materials, and the mechanisms of action of GB, NE, and GN on P. donghaiense were analyzed via RNA-seq. In total, 59,151, 152, and 25,363 differentially expressed genes (DEGs) were identified in algae treated with GB, NE, and GN, respectively. The top three GO- and KEGG-annotated DEGs were shared between GB and GN treatments, indicating that GB was the primary active component of GN. KEGG enrichment further showed that photosynthesis-related pathways were among the top five pathways affected by GN. Key genes in photosystem II (PsbA-E), cytochrome b₆/f complex (PetD), and ATP synthase (atpD) were downregulated, and 10 photosynthesis-antenna protein genes (Lhca1–4, Lhcb1–6) were upregulated under GN treatment. However, most of these genes did not show significant expression under the GB treatment, except for Lhca1 and Lhcb1–2. Furthermore, NE treatment upregulated ushA and downregulated pncC, disrupting algal nucleotide and NAD⁺ biosynthesis. This suggests that NE may accelerate GB-induced inhibition of photosynthesis-related pathways. These findings provide new insights into the molecular mechanisms underlying P. donghaiense exposure to GN and provide a theoretical basis for the prevention and control of harmful algal blooms.