Nitrogen availability influences Septoria defence in wheat by modulating WRKY transcription factor gene expression.

氮可用性通过调节 WRKY 转录因子基因表达来影响小麦壳针孢防御。

• 批准号: BB/M022048/1
• 负责人: Ari Sadanandom
• 金额: $ 18.61万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FM022048%2F1
• 关键词: Nitrogen; availability; influences; Septoria; defence

The foundation of global food security is built on the three cereals wheat, rice and maize, where wheat is the leading source of vegetable protein in human food. In the UK this cereal is the most important crop grown with an annual value of about £1.2 billion. The average yield of wheat in the field in the UK is currently 8.4 tonnes/ha, but this yield is dependent on high levels of mineral fertilizer (especially Nitrogen, Phosphorus and Potassium) and pesticide usage. Nitrogen (N) fertiliser use is of concern because it is associated both with high levels of energy use and greenhouse gas emissions (e.g. CO2, N2O) that cause climate change, in addition to eutrophication of fresh water and marine ecosystems. However, nitrogen fertilisation is required for achieving high yield in wheat, and increasing sustainability through decrease in nitrogen input is not commercially feasible due to the resulting fall in yield. Given that high-nitrogen nutrient regimes are reality in the field, decreasing pesticide usage is a target for enhancing sustainability of wheat production.An undesirable side-effect of nitrogen fertilisation is that it increases susceptibility to pathogens. There is increasing evidence that high soil nitrogen enhances the development of fungal pathogens such as Septoria that causes wheat leaf blotch disease (Simón et al 2003; Loyce et al 2008). The mechanisms leading to these nutrient induced changes in disease development are not known. Septoria leaf blotch (STB) is currently the most important disease of wheat in Europe and is among the top three most economically damaging diseases of this crop in the United States. Despite the importance of STB, there is very little information available on the defence mechanisms or immune responses that allow wheat to counter Septoria infection. Fungicides provide the only control measure for this devastating disease, but extensive applications of fungicides increase the worldwide economic costs attributed to STB. In addition, STB outbreaks are becoming more prevalent as currently available fungicides are becoming less effective against new resistant strains of Septoria. Therefore there is an urgent need to develop new strategies to combat STB in the field. The industrial partners (KWS) in the proposal recognise that exploiting endogenous defence mechanisms that do not rely on fungicides may provide an alternative method to control this disease, and that an understanding of why Nitrogen nutrient level and disease resistance are inversely correlated is likely to lead to strategies which will enable exploitation of endogenous defence. Our preliminary data have suggested that a family of transcription factors (Tfs), the WRKY genes that have been shown to be central to plant defence in model systems, form a link between nitrogen input and Septoria disease resistance in the field. We propose to investigate the roles of these WRKY gene family TFs to reveal the identity of the specific WRKYs which are critical for Septoria resistance in the field under varying nitrogen levels and mechanisms which can be exploited to boost Septoria resistance under the high input growth conditions necessary for maintaining yield. The overall objective of this project is to gain an understanding of how the nutrient regime under which cereals are grown affects their susceptibility to STB disease, with the ultimate aim of manipulating this relationship to allow enhanced disease resistance to be retained under high or optimum nitrogen input growth conditions.

全球粮食安全的基础是小麦、水稻和玉米这三种谷物，其中小麦是人类食物中植物蛋白的主要来源。在英国，这种谷物是最重要的作物，年产值约为12亿英镑。目前，英国小麦的平均产量为8.4吨/公顷，但这一产量取决于高水平的矿物肥料（特别是氮、磷和钾）和农药的使用。氮肥的使用令人担忧，因为它与高水平的能源使用和温室气体排放（如CO2，N2 O）有关，导致气候变化，以及淡水和海洋生态系统的富营养化。然而，氮肥是实现小麦高产所必需的，并且由于产量下降，通过减少氮投入来提高可持续性在商业上是不可行的。鉴于高氮营养制度在田间是现实的，减少农药的使用是提高小麦生产可持续性的目标。氮肥的一个不良副作用是它增加了对病原体的易感性。越来越多的证据表明，高土壤氮会促进真菌病原体的发展，如引起小麦叶斑病的壳针孢属（Simón et al 2003; Loyce et al 2008）。导致这些营养素诱导的疾病发展变化的机制尚不清楚。壳针孢叶斑病（STB）是目前欧洲小麦最重要的病害，也是美国小麦三大经济损失最大的病害之一。尽管STB的重要性，但关于小麦抵抗壳针孢属感染的防御机制或免疫反应的信息很少。杀真菌剂提供了唯一的控制措施，这种毁灭性的疾病，但杀真菌剂的广泛应用增加了世界范围内的经济成本归因于STB。此外，STB爆发正变得更加普遍，因为目前可用的杀真菌剂对壳针孢属的新抗性菌株变得不那么有效。因此，迫切需要制定新的战略来打击该领域的STB。该提案中的工业合作伙伴（KWS）认识到，利用不依赖于杀真菌剂的内源防御机制可能提供一种控制这种疾病的替代方法，并且理解为什么氮营养水平和抗病性呈负相关，可能会导致能够利用内源防御的策略。我们的初步数据表明，一个家族的转录因子（Tfs），WRKY基因已被证明是中央的植物防御模型系统中，氮输入和壳针孢抗病性之间的联系，在外地。我们建议研究这些WRKY基因家族TF的作用，以揭示特定WRKY的身份，这些WRKY在不同的氮水平和机制下对田间的壳针孢属抗性至关重要，这些机制可用于在维持产量所需的高输入生长条件下提高壳针孢属的抗性。该项目的总体目标是了解谷物生长的营养状况如何影响其对STB疾病的易感性，最终目的是操纵这种关系，以使在高氮或最佳氮输入生长条件下保持增强的抗病性。

项目成果

The ubiquitin conjugating enzyme, TaU4 regulates wheat defence against the phytopathogen Zymoseptoria tritici.

• DOI: 10.1038/srep35683
• 发表时间: 2016-10-19
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Millyard L;Lee J;Zhang C;Yates G;Sadanandom A
• 通讯作者: Sadanandom A

BTB-BACK Domain Protein POB1 Suppresses Immune Cell Death by Targeting Ubiquitin E3 ligase PUB17 for Degradation.

BTB背域蛋白POB1通过靶向泛素E3连接酶Pub17抑制免疫细胞死亡。

• DOI: 10.1371/journal.pgen.1006540
• 发表时间: 2017-01
• 期刊: PLoS genetics
• 影响因子: 4.5
• 作者: Orosa B;He Q;Mesmar J;Gilroy EM;McLellan H;Yang C;Craig A;Bailey M;Zhang C;Moore JD;Boevink PC;Tian Z;Birch PR;Sadanandom A
• 通讯作者: Sadanandom A