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、水稻和玉米三种谷物，其中小麦是人类食品中植物蛋白的主要来源。在英国，这种谷物是最重要的农作物，年产值约为 12 亿英镑。目前英国田间小麦的平均产量为 8.4 吨/公顷，但这一产量依赖于高水平的矿物肥料（特别是氮、磷和钾）和农药的使用。氮肥的使用备受关注，因为除了导致淡水和海洋生态系统富营养化外，它还与高水平的能源使用和导致气候变化的温室气体排放（例如二氧化碳、氧化亚氮）有关。然而，小麦高产需要施氮肥，而通过减少氮肥投入来提高可持续性在商业上不可行，因为这会导致产量下降。鉴于高氮营养状况在田间的现实情况，减少农药的使用是提高小麦生产可持续性的一个目标。施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生长，例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) 是目前欧洲最重要的小麦病害，也是美国小麦作物最具经济破坏性的三大病害之一。尽管 STB 很重要，但有关小麦抵抗壳针孢感染的防御机制或免疫反应的信息却很少。杀菌剂是这种毁灭性疾病的唯一控制措施，但杀菌剂的广泛应用增加了 STB 造成的全球经济成本。此外，由于目前可用的杀菌剂对新的壳针孢耐药菌株的效果越来越差，STB 爆发变得越来越普遍。因此，迫切需要制定新的策略来对抗该领域的STB。该提案中的工业合作伙伴（KWS）认识到，利用不依赖杀菌剂的内源防御机制可能会提供控制这种疾病的替代方法，并且了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，转录因子 (Tfs) 家族（WRKY 基因已被证明是模型系统中植物防御的核心）在田间氮输入和壳针孢抗病性之间形成了联系。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 对田间不同氮水平下的壳针孢抗性至关重要，并且可利用其在维持产量所需的高投入生长条件下增强壳针孢抗性的机制。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，最终目标是操纵这种关系，以便在高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