College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China.
State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
Ultrason Sonochem. 2021 Aug;76:105649. doi: 10.1016/j.ultsonch.2021.105649. Epub 2021 Jun 20.
Blast is one of the most devastating fungal diseases of rice caused by Magnaporthe oryzae. Plant essential oil (EO) can function as antifungal agents and are regarded as a safe and acceptable method for plant disease control. However, EOs are unstable and hydrophobic, which limits its use. In the present study, we aimed for the preparation and characterization of a nanoemulsion (NE) from green tea essential oil (GTO) by ultrasonication method and determined the antifungal activity of NE onM. oryzae. The particle size and zeta potential of the NE were 86.98 nm and -15.1 mV, respectively. The chemical composition and functional groups of GTO and NE were studied by using GC-MS analysis, portable Raman spectroscopy, and FTIR coupled with chemometric analysis. GC-MS analysis showed the major components in GTO and NE were n-Hexyl cinnamaldehyde and L-α-Terpineol. Both GTO and NE showed good antioxidant activity and total phenol content. Moreover, the NE showed good antifungal activity againstM. oryzae which was further confirmed by scanning electron microscopy (SEM) examination. Also, confocal Raman micro-spectroscopy (CRM) revealed the antifungal mechanism of GTO and NE on M. oryzae which proves the cell damage. To the best of our knowledge, this is the first study on the antifungal activity of GTO and NE against M. oryzae and also the use of CRM for the evaluation of the chemical changes in single fungal hyphae in a holistic approach. This study suggests that the prepared NE could be a potential candidate for use as a substitute for synthetic fungicides.
爆发病是由稻瘟病菌引起的最具破坏性的水稻真菌病害之一。植物精油 (EO) 可以作为抗真菌剂，被认为是一种安全且可接受的植物病害控制方法。然而，EO 不稳定且疏水，这限制了其使用。在本研究中，我们旨在通过超声法制备和表征绿茶精油 (GTO) 的纳米乳液 (NE)，并确定 NE 对稻瘟病菌的抗真菌活性。NE 的粒径和zeta 电位分别为 86.98nm 和-15.1mV。通过使用 GC-MS 分析、便携式拉曼光谱和 FTIR 结合化学计量学分析研究了 GTO 和 NE 的化学成分和官能团。GC-MS 分析表明，GTO 和 NE 的主要成分分别为正己基肉桂醛和 L-α-萜品醇。GTO 和 NE 均表现出良好的抗氧化活性和总酚含量。此外，NE 对稻瘟病菌表现出良好的抗真菌活性，这一点通过扫描电子显微镜 (SEM) 检查得到了进一步证实。此外，共聚焦拉曼微光谱 (CRM) 揭示了 GTO 和 NE 对稻瘟病菌的抗真菌机制，证明了细胞损伤。据我们所知，这是首次研究 GTO 和 NE 对稻瘟病菌的抗真菌活性，也是首次使用 CRM 全面评估单条真菌菌丝的化学变化。本研究表明，所制备的 NE 可能是替代合成杀菌剂的潜在候选物。
