寄生植物ストライガのゲノム研究

在非洲，对作物生产最重要的经济限制包括独脚金物种i。例如，S. hermonthica和S.除其他外，亚洲热带雨林的干旱影响到高粱、小米、玉米、甘蔗和豇豆的生产，每年造成高达10亿美元的损失，影响到1亿多农民。控制独脚金的基本策略是防止其繁殖，破坏其土壤种子库，并限制其向新的未受影响的地区蔓延。为此，已经鉴定了对独脚金表现出抗性的几种作物物种（包括高粱）的栽培品种和野生近缘种。在水稻中，发现日本晴，一种粳稻品种，对独脚金具有抗性。然而，耐药性的分子机制还不清楚。在我们的研究中，我们进行了深入的表征SA和JA在水稻防御Striga hermonthica的作用。我们发现茉莉酸（JA）和水杨酸（SA）的防御途径， ...更多信息 在水稻根部感染后产生。使用JA和SA途径突变体，我们发现，抑制JA生物合成导致严重的独脚金易感性，只有恢复与JA处理植物。另一方面，SA缺失的水稻对独脚金具有抗性。抗性表型的特征在于强烈诱导JA防御途径。在感染Striga的水稻根中，我们发现一个名为OsWRKY45的基因高度表达。当我们敲除该基因时，植株对独脚金感染高度敏感，并且通过加入JA恢复了敏感性。这些结果强调了OsWRKY45在调节JA和SA防御途径中对Striga寄生的抗性的重要性。这些数据提供给我们的知识，第一次深入了解的阻力机制，使单子叶植物抵抗独脚金寄生，并揭示了一些以前未知的防御途径串扰的特点。复杂的JA和SA相互作用的机制的知识是必要的，以了解抗性的演变和发展成功的解决方案，寄生杂草在农业中的问题。少

In Africa, the most economically important constraints to crop production include Striga species i. e., S. hermonthica and S. asiatica, among others, which affect the production of sorghum, millet, maize, sugarcane and cowpea resulting in losses of up to USD 1 billion annually affecting over 100 million farmers. The fundamental strategies to control Striga are to prevent their reproduction, to destroy their soil seed bank and to limit their spread to new uninfested areas. Towards this end, cultivars and wild relatives of several crop species including sorghum, which show resistance to Striga have been identified. In rice, it was found that Nipponbare, a japonica cultivar is resistant against Striga. However, the molecular mechanisms underlying resistance are not well understood. In our study, we conducted an in-depth characterization of the roles of SA and JA in rice defence against Striga hermonthica. We found out that jasmonic acid (JA) and salicylic acid (SA) defence pathways were i … More nduced in rice roots after infection. Using JA and SA pathway mutants, we found that inhibiting JA biosynthesis resulted in severe Striga susceptibility only recovered by treating plants with JA. On the other hand, SA-deficient rice were resistant against Striga. The resistance phenotype was characterized by a strong induction of the JA defence pathway. In the Striga-infected rice roots, we found that a gene called OsWRKY45 was highly expressed. When we knocked down this gene, the plants were highly susceptible to Striga infection and the susceptibility was recovered by addition of JA. These results highlighted the significance of OsWRKY45 in regulating both the JA and SA defence pathways in resistance against Striga parasitism. These data offer to our knowledge, the first insight into the resistance mechanisms that enable monocots to resist Striga parasitism and have revealed several previously unknown characteristics of defence pathway crosstalk. Knowledge of the mechanisms involved in the complex JA and SA interactions are necessary to understand the evolution of resistance and the development of successful solutions to parasitic weed problems in agriculture. Less