Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China.
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China.
Sci Total Environ. 2020 Jun 1;719:137376. doi: 10.1016/j.scitotenv.2020.137376. Epub 2020 Feb 17.
Bioherbicide terpinolene is widely employed in the agricultural field because of its unique phytotoxic properties. However, little is known about the toxicity of bioherbicide on harmful algal blooms (HABs) and its mechanisms. Therefore, in this study, the inhibiting effect of bioherbicide terpinolene on the growth and physiological change of Microcystis aeruginosa was determined. Results showed that the cell density and photosynthetic activity of microalgae were significantly inhibited by terpinolene. Activities of nitrate reductase (NR) and glutamine synthetase (GS) were decreased separately by 25.38% and 42.75% after 4 d of exposure to 1.47 mM terpinolene, suggesting the inhibiting effect of terpinolene on algal nitrogen metabolism. However, the transcript abundance of genes related to membrane protein cytochrome c oxidase subunit II (COX II) and ATP-binding cassette transporters (ABC transporter) were enhanced separately by 3.15 and 1.69-fold compared with control, suggesting the resistance response of cells to terpinolene stress. Additionally, terpinolene not only increased the content of endogenous phytohormones including indole-3-acetic acid (IAA), zeatin, and brassinolide, but also inhibited the expression of genes related to calcium-binding protein (CaBPs), one kind of calcium (Ca) sensors, suggesting its regulation on algal signal molecules. These findings helped to understand the ecotoxicity of terpinolene and guide the rational use of bioherbicide in agriculture.
生物除草剂松油烯因其独特的植物毒性特性而被广泛应用于农业领域。然而，关于生物除草剂对有害藻华（HABs）的毒性及其机制知之甚少。因此，在本研究中，测定了生物除草剂松油烯对铜绿微囊藻生长和生理变化的抑制作用。结果表明，松油烯显著抑制了微藻的细胞密度和光合作用活性。暴露于 1.47mM 松油烯 4 天后，硝酸还原酶（NR）和谷氨酰胺合成酶（GS）的活性分别降低了 25.38%和 42.75%，表明松油烯对藻类氮代谢有抑制作用。然而，与对照组相比，与膜蛋白细胞色素 c 氧化酶亚基 II（COX II）和 ABC 转运蛋白相关的基因的转录丰度分别增加了 3.15 倍和 1.69 倍，表明细胞对松油烯胁迫的抗性反应。此外，松油烯不仅增加了内源性植物激素（包括吲哚-3-乙酸（IAA）、玉米素和油菜素内酯）的含量，还抑制了与钙结合蛋白（CaBPs）相关基因的表达，CaBPs 是一种钙（Ca）传感器，表明其对藻类信号分子的调节作用。这些发现有助于了解松油烯的生态毒性，并指导生物除草剂在农业中的合理使用。
