农科院植物线虫创新团队合作揭示维生素B1诱导水稻对根结线虫
2016年5月，院选核心期刊《molecular Plant Pathology》上以封面文章的形式发表中国农业科学院植物保护研究所植物线虫病害流行与控制创新团队黄文坤博士与比利时科学家合作发表外源物质诱导植物对根结线虫抗性方面取得的研究进展文章，研究发现维生素B1诱导水稻对根结线虫抗性的生化与分子生物学机制。研究成果题为Thiamine-induced priming against root-knot nematode infection inrice involves lignification and hydrogen peroxide generation，黄文坤博士为第一作者。
维生素B1(Thiamine)可以作为诱导因子，激发植物对真菌、细菌等病原物的抗性，但在诱导植物对根结线虫抗性方面研究较少。通过根结线虫接种前使用微量的维生素B1，可以激发水稻的防御反应，诱导过氧化氢累积和木质素沉积，增加苯丙氨酸代谢途径中OsPAL1和 OsC4H的转录水平，降低水稻根结线虫的侵入数量与为害程度，延缓根结线虫的发育进程，但对巨细胞发育没有显著影响。通过使用苯丙氨酸途径的抑制剂，显著阻碍了维生素B1的激发作用，进一步证实了维生素B1诱导的水稻对根结线虫的抗性机制是通过激发水稻的苯丙氨酸代谢途，诱导木质素沉积和过氧化氢累积等实现。该研究结果对揭示外源物质诱导水稻对根结线虫抗性的机制提供了新的方法，对发展水稻根结线虫绿色防控技术体系提供了新的途径，具有重要的理论和应用价值，是植物线虫病害诱导抗性方面的重要发现。
原文链接：
Thiamine-induced priming against root-knot nematode infection in rice involves lignification and hydrogen peroxide GENEration
原文摘要：
Thiamine (vitamin B1, VB1) can act as a plant defence trigger, or priming agent, leading to a rapid counterattack on pathogen invasion. In this study, the priming effect of thiamine on rice (Oryza sativa cv. Nipponbare) and its activity against root-knot nematode (Meloidogyne graminicola) infection were evaluated. Thiamine treatment and subsequent nematode inoculation activated hydrogen peroxide (H2O2) accumulation and lignin deposition in plant roots, and this correlated with enhanced transcription of OsPAL1 and OsC4H, two genes involved in the phenylpropanoid pathway. The number of nematodes in rice roots was slightly but significantly reduced, and the development of the nematodes was delayed, whereas no direct toxic effects of VB1 on nematode viability and infectivity were observed. The combined application of thiamine with l-2-aminooxy-3-phenylpropionic acid (AOPP), an inhibitor of phenylalanine ammonia-lyase (PAL), significantly hampered the VB1-priming capacity. These findings indicate that thiamine-induced priming in rice involves H2O2 and phenylpropanoid-mediated lignin production, which hampers nematode infection. Further cellular and molecular studies on the mechanism of thiamine-induced defence will be useful for the development of novel nematode control strategies.
作者：黄文坤
