College of Tobacco Science, Henan Agricultural University, National Tobacco Cultivation and Physiology and Biochemistry Research Center, Key Laboratory for Tobacco Cultivation of Tobacco Industry, Zhengzhou, Henan, China.
International Center for Biosaline Agriculture, ICBA, Dubai, P.O. Box 14660, United Arab Emirates; Soil and Water Research Department, Nuclear Research Center, Egyptian Atomic Energy Authority, Cairo 13759, Egypt.
Pestic Biochem Physiol. 2024 Feb;199:105803. doi: 10.1016/j.pestbp.2024.105803. Epub 2024 Jan 23.
Tobacco black shank (TBS) is a soil-borne fungal disease caused by Phytophthora nicotiana (P. nicotianae), significantly impeding the production of high-quality tobacco. Molybdenum (Mo), a crucial trace element for both plants and animals, plays a vital role in promoting plant growth, enhancing photosynthesis, bolstering antioxidant capacity, and maintaining ultrastructural integrity. However, the positive effect of Mo on plant biotic stress is little understood. This study delves into the inhibitory effects of Mo on P. nicotianae and seeks to unravel the underlying mechanisms. The results showed that 16.32 mg/L of Mo significantly inhibited mycelial growth, altered mycelial morphological structure, damaged mycelial cell membrane, and ultimately led to the leakage of cell inclusions. In addition, 0.6 mg/kg Mo applied in soil significantly reduced the severity of TBS. Mo increased photosynthetic parameters and photosynthetic pigment contents of tobacco leaves, upregulated expression of NtPAL and NtPPO resistance genes, as well as improved activities of SOD, POD, CAT, PPO, and PAL in tobacco plants. Furthermore, Mo could regulate nitrogen metabolism and amino acids metabolism to protect tobacco plants against P. nicotianae infection. These findings not only present an ecologically sound approach to control TBS but also contribute valuable insights to the broader exploration of the role of microelements in plant disease management.
烟草黑胫病（TBS）是一种由烟草疫霉（P. nicotianae）引起的土传真菌病害，严重阻碍了优质烟草的生产。钼（Mo）是动植物都必需的微量元素，它在促进植物生长、增强光合作用、增强抗氧化能力和维持超微结构完整性方面起着至关重要的作用。然而，Mo 对植物生物胁迫的积极影响却知之甚少。本研究探讨了 Mo 对烟草疫霉的抑制作用，并试图揭示其潜在的机制。结果表明，16.32mg/L 的 Mo 显著抑制了菌丝生长，改变了菌丝的形态结构，破坏了菌丝细胞膜，最终导致细胞内含物的渗漏。此外，土壤中施入 0.6mg/kg 的 Mo 可显著降低 TBS 的严重度。Mo 增加了烟草叶片的光合参数和光合色素含量，上调了 NtPAL 和 NtPPO 抗性基因的表达，并提高了烟草植株中 SOD、POD、CAT、PPO 和 PAL 的活性。此外，Mo 可以调节氮代谢和氨基酸代谢，从而保护烟草植物免受烟草疫霉的感染。这些发现不仅为控制 TBS 提供了一种生态友好的方法，也为更广泛地探索微量元素在植物病害管理中的作用提供了有价值的见解。
