14CONFAP: Brazil-UK Partnership on Delivering Pest Resilience in Brazilian Smallholder Maize Crops

植物已经进化出了复杂的防御策略，利用各种可用于作物保护的诱导防御机制来对抗生物胁迫（害虫）。它们直接产生对害虫具有拮抗作用的挥发性亲脂小分子，间接释放亲脂小分子作为胁迫信号吸引害虫天敌。此外，邻近的植物已经进化到通过诱导或增强（引发）它们的防御反应来响应胁迫信号。在检测到植物胁迫信号时引发或引发作物植物防御的能力提供了开发新的混合种植系统的机会，由此与哨兵（保卫）作物上的初始害虫攻击相关的所识别的胁迫信号可用于激活主要作物中的防御。该项目的总体目标是将英国和巴西的合作伙伴聚集在一起，在巴西的小农户农场开发玉米对秋粘虫（草地贪夜蛾）的适应能力。这将基于玉米/S的化学生态学。frugiperda相互作用，用于部署混合种植系统，该系统利用来自最初受攻击植物的植物/植物信号，用于主要作物的保护（天敌）生物防治。通过对不同玉米品种和地方品种的评价，研究了不同品种和地方品种对S. frugiperda诱导的应激信号。植物将不受挑战或用S.将通过空气夹带获得含有诱导应力信号的草地贪夜蛾和顶空提取物。胁迫信号将使用GC-FID进行分析，并使用GC-MS进行鉴定。为了确认所鉴定的胁迫信号的生物活性，将进行生物测定，以评估其对害虫天敌觅食行为的影响。为了评估胁迫信号诱导邻近玉米品种和地方品种的防御，将未受损的邻近玉米植株（受体）暴露于S.受害植物（捐助者）。然后从受体植物收集诱导的信号，并通过GC-FID和GC-MS鉴定，以观察供体胁迫信号是否在受体中引起防御反应。为了确认受体释放的应激信号的生物活性，将进行生物测定以评估它们对天敌觅食行为的影响。为了评估胁迫信号暴露和未暴露受体植物之间胁迫信号生物合成基因的差异表达，将从信号暴露和未暴露受体玉米品种和地方品种中提取信使RNA，并进行下一代测序转录组分析。将使用真实的时间PCR分析来确认特异性编码参与胁迫信号生物合成的酶的推定生物合成基因的差异表达。这些基因将作为筛选抗感玉米品种和地方品种的靶标。frugiperda，其中基因表达可以通过暴露于所鉴定的胁迫信号来引发。将在米纳斯吉拉斯的Embrapa Maize和Sorcium试验田进行实地研究。地块将与玉米品种和地方品种的混合种植进行组织，这些玉米品种和地方品种被证明要么对秋粘虫损害高度敏感，并发出植物胁迫信号（哨兵作物），要么通过激发自身防御（主要作物）来响应胁迫信号。田间试验完成后，巴西农业研究院认识的农民和推广官员将接受农民田间学校/农民田间论坛培训，在那里他们将接受关于保护玉米的混合种植战略的教育。一旦制定了控制秋粘虫的混合种植制度战略，并在农民田间学校/论坛上成功演示，将以简单的语言记录在概况介绍和插图手册中。

Plants have evolved sophisticated defence strategies against biotic stress (pests) using a variety of inducible defence mechanisms that can be exploited in crop protection. Directly, they produce volatile small lipophilic molecules (SLMs) that are antagonistic to pests, and indirectly, they release SLMs as stress signals to attract pest natural enemies. Furthermore, neighbouring plants have evolved to respond to the stress signalling by induction or augmentation (priming) of their defence response. The ability to elicit or prime crop plants for defence upon detection of plant stress signalling provides an opportunity to develop new mixed cropping systems, whereby the identified stress signals associated with initial pest attack on sentinel (guard) crops can be used for the activation of defence in main crops. The overall aim of this project is to bring together UK and Brazilian partners to develop resilience in maize against fall armyworm, Spodoptera frugiperda, in smallholder farms in Brazil. This will be based upon the chemical ecology of maize/S. frugiperda interactions, for the deployment of a mixed cropping system that exploits plant/plant signalling from initially attacked plants for conservation (natural enemy) biocontrol in main crops. Different cultivars and landraces of maize will be evaluated to characterise the emission of S. frugiperda-induced stress signalling. Plants will be either unchallenged or challenged with S. frugiperda and headspace extracts containing the induced stress signals will be obtained by air entrainment. The stress signals will be analysed using GC-FID and identified using GC-MS. To confirm the biological activity of the identified stress signals, bioassays will be conducted to evaluate their influence on the foraging behaviour of pest natural enemies. To evaluate stress signal induction of defence in neighbouring maize cultivars and landraces, undamaged neighbouring maize plants (recipients) will be exposed to the stress signals released by S. frugiperda-damaged plants (donors). The induced signalling will then be collected from recipient plants and identified by GC-FID and GC-MS to see if the donor stress signalling has elicited a defence response in recipients. To confirm the biological activity of the stress signals released by recipients, bioassays will be conducted to evaluate their influence on the foraging behaviour of natural enemies. To evaluate differential expression of stress signal biosynthesis genes between stress-signal exposed and unexposed recipient plants, messenger RNA will be extracted from signal-exposed and unexposed recipient maize cultivars and landraces and subjected to Next Generation Sequencing transcriptome analysis. The differential expression of putative biosynthesis genes that specifically encode enzymes involved in stress signal biosynthesis will be confirmed using real time PCR analysis. These genes will be identified as targets for selection of maize cultivars and landraces with resilience to S. frugiperda, in which gene expression can be elicited by exposure to the stress signals identified. Field studies will be carried out on experimental-based plots at Embrapa Maize and Sorghum in Minas Gerais. Plots will be organised with mixed cropping of the maize cultivars and landraces that are shown to be either highly susceptible to fall armyworm damage and emit plant stress signalling (sentinel crops), or respond to stress signalling though elicitation of their own defence (main crops). After completion of the field experiment, farmers and extension officers known to Embrapa will be taken though Farmers Field Schools/Farmers Field Forum training where they will be educated on the mixed cropping strategy for maize protection. Once the mixed cropping system strategy for control of fall armyworm is developed and successfully demonstrated in farmer field schools/forums, it will be documented in simple language in factsheets and illustrated handbooks.