Endophyte Infection and Methyl Jasmonate Treatment Increased the Resistance of Achnatherum sibiricum to Insect Herbivores Independently
Endophyte Infection and Methyl Jasmonate Treatment Increased the Resistance of Achnatherum sibiricum to Insect Herbivores Independently
复制标题
内生菌感染和茉莉酸甲酯处理独立增加西伯利亚芨芨草对食草昆虫的抗性
DOI：
10.3390/toxins11010007
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发表时间：
2019-01-01
期刊：
影响因子：
4.2
通讯作者：
Ren, Anzhi
中科院分区：
文献类型：
--
作者：
Qin, Junhua;Wu, Man;Ren, Anzhi
生物碱通常被认为是负责保护内生菌感染（EI）的草从他们的食草动物。内生真菌感染能增强EI草对植食性害虫的抗性吗？相关研究有限。在内蒙古草原地区，稗草内生真菌侵染率高，但生物碱含量低。蝗虫是常见的草食性昆虫。在本研究中，A.西伯利亚被用作植物材料。茉莉酸甲酯（MJ，当外源施用时，可以诱导类似于草食动物损害的反应）处理。研究了内生菌感染和MJ处理对白叶枯病菌抗性的影响。sibiricum对东亚飞蝗的影响。我们发现，蝗虫更喜欢EF（内生菌免费）植物EI植物在选择和无选择的喂养实验。内生菌感染增强了A.西伯利亚蝗虫。内生菌感染降低了可溶性糖含量，提高了总酚含量和苯丙氨酸解氨酶（PAL）活性，这可能是导致A.西伯利亚蝗虫。MJ处理与内生菌感染对寄主生长的影响存在交互作用。MJ处理是内生菌感染的植物促生长效应的负调节剂。MJ处理和内生菌感染对寄主的防御特性没有交互作用。在未接触蝗虫的组中，MJ处理和内生菌感染在降低可溶性糖含量、提高总酚含量和PAL活性方面具有相似的效果。在蝗虫暴露组中，MJ处理对上述特性的影响消失，而内生菌感染的影响更加明显。所有这些结果表明，即使内生菌产生很少的生物碱，他们仍然可以增加天然草对昆虫食草动物的抗性。此外，内生菌感染可能介导宿主的防御反应，不依赖于茉莉酸（JA）途径。
Alkaloids are usually thought to be responsible for protecting endophyte-infected (EI) grasses from their herbivores. For EI grasses that produce few alkaloids, can endophyte infection enhance their resistance to herbivores? Related studies are limited. In the Inner Mongolian steppe, Achnatherum sibiricum is highly infected by Epichloë endophytes, but produces few alkaloids. Locusts are the common insect herbivores of grasses. In this study, A. sibiricum was used as plant material. Methyl jasmonate (MJ, when applied exogenously, can induce responses similar to herbivore damage) treatment was performed. The effects of endophyte infection and MJ treatment on the resistance of A. sibiricum to Locusta migratoria were studied. We found that locusts preferred EF (endophyte-free) plants to EI plants in both choice and no-choice feeding experiments. Endophyte infection enhanced the resistance of A. sibiricum to locusts. Endophyte infection decreased soluble sugar concentrations, while it increased the total phenolic content and phenylalanine ammonia lyase (PAL) activity, which may contribute to the resistance of A. sibiricum to locusts. There was an interaction effect between MJ treatment and endophyte infection on the growth of the host. MJ treatment was a negative regulator of the plant growth-promoting effects of endophyte infection. There was no interaction effect between MJ treatment and endophyte infection on the defense characteristics of the host. In groups not exposed to locusts, MJ treatment and endophyte infection had a similar effect in decreasing the soluble sugar content, while increasing the total phenolic content and the PAL activity. In groups exposed to locusts, the effect of MJ treatment on the above characteristics disappeared, while the effect of endophyte infection became more obvious. All of these results suggest that even for endophytes producing few alkaloids, they could still increase the resistance of native grasses to insect herbivores. Furthermore, endophyte infection might mediate the defense responses of the host, independent of jasmonic acid (JA) pathways.