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

Lead Research Organisation: Rothamsted Research
Department Name: Biological Chemistry & Crop Protection

Abstract

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.

Technical Summary

Different cultivars and landraces of maize (L-MIRT-2A, Sintético Spodoptera, HS-MIRT-4, Zapalote Chico and L3, from Embrapa Germplasm Bank) will be evaluated to characterise the emission of S. frugiperda-induced 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 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, ie. the parasitic wasps Trichogramma pretiosum and Telenomus remus. 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 T. pretiosum and T. remus. Field studies will be carried out on experimental-based plots at Embrapa Maize and Sorghum. 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/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 demonstrated, it will be documented in simple language, in factsheets and illustrated handbooks.

Planned Impact

N/A

Publications

10 25 50
 
Description This project brought together UK (Rothamsted Research) and Brazilian (Embrapa-Genetic Resources and Biotechnology) expertise to develop resilience in maize against fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) in smallholder farms in Brazil, based upon the chemical ecology of maize/S. frugiperda interactions. Our work tested the hypothesis that production of the volatile defence secondary metabolites in maize under biotic stress (S. frugiperda) is via CYP450-mediated oxidative stress.

Using dynamic headspace collection, high resolution gas chromatography (GC-FID), GC coupled-mass spectrometry (GC-MS) and GC peak enhancement with authentic samples of compounds prepared by chemical synthesis, we demonstrated that challenge of Brazilian maize cultivars with larvae of S. frugiperda elicits cultivar-dependent production of volatile secondary metabolites that cause adult S. frugiperda repulsion and recruitment of a natural enemy parasitoid (parasitic wasp). We showed that production of the volatile metabolites in unchallenged maize can be primed by airborne stress signalling originating from neighbouring S.frugiperda-damaged maize. We successfully tested our hypothesis that S. frugiperda damage causes a cultivar-dependent increase in production of benzoxazinoids (BXs). We conducted preliminary field studies with selected maize cultivars on experimental plots at Embrapa-Genetic Resources and Biotechnology, and showed that there is statistically significant reduction in S. frugiperda populations. Using next generation sequencing (comparative RNA-seq) we showed differential expression of putative CYP450 genes in maize upon S. frugiperda challenge and exposure to airborne stress signalling.

Brazil is the third largest global producer of maize, and although it is the fourth highest exporter, most of the production is destined for internal markets, where it is stall an important food crop in many regions for the poorest of the population. This project is primarily relevant to the economic development and welfare in Brazil (upper middle-income country), where approximately 18 million poor rural people, with food and nutrition security remain a problem in some communities. The findings of the novel basic research reported here, on the ecology of plant/insect interactions, will underpin the development of innovative, sustainable and low-tech technology for management of an economically important moth pest on maize on smallholder farms in Brazil, while strengthening capacity in sustainable pest management. The next challenge is to select and develop maize cultivars that possess the volatile defence signalling trait for use as sentinel plants (detecting and responding to the pest problem) and smart main plants (selected to respond to the sentinel plant volatile signalling) in Brazilian smallholder maize production, and to translate the basic research to on-farm pest management.
Exploitation Route Globally, sustainable intensification of crop production systems requires the delivery of new crop protection tools via seed, ie. GM, and the enhancement of ecosystem services, i.e. beneficial natural enemies, from land set aside as natural habitats. The findings here underpin the practical development of new crop protection interventions based on chemical ecology, specifically plant defence signalling, and which can deliver crop protection via smart plants, sentinel technology and recruitment of ecosystem services i.e. beneficial natural enemy populations for conservation biological control.
Sectors Agriculture

Food and Drink

 
Description Alliance for Sustainable Agriculture Previously: UK-Brazil Partnership for Yield Stability & Protection in a Changing Climate (PYSP)
Amount £300,000 (GBP)
Funding ID BBS/OS/NW/000001 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 03/2015 
End 03/2019
 
Description Novel Semiochemical-Based Management of Fall Armyworm (FAW) in Brazil using Companion Crops
Amount £46,176 (GBP)
Funding ID BB/R020000/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 04/2018 
End 10/2019
 
Description Smart Maize for FAW Management in Brazil 
Organisation Brazilian Agricultural Research Corporation
Department Embrapa Genetic Resources and Biotechnology
Country Brazil 
Sector Private 
PI Contribution Principal Investigator, co-investigator
Collaborator Contribution Co-investigator
Impact Work in progress
Start Year 2015
 
Description BBSRC-FAPESP workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Attended BBSRC-FAPESP Joint Pump-Priming Awards for AMR and Insect Pest Resistance in Agriculture Partnership Building Workshop, FAPESP headquarters, Sao Paulo, 4-6 October 2017. Gave presentation "Smart Crop Protection".
Year(s) Of Engagement Activity 2017
 
Description ERANET Workshop on Sustainable Tomato Production 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Workshop at University of Nice, 13th July 2017. Gave presentation "Recruitment of Ecosystem Services for Pest Management using Smart Plants"
Year(s) Of Engagement Activity 2017
 
Description Institute Research Day presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Institute Research Day presentation, 9th May 2017
Year(s) Of Engagement Activity 2017
 
Description International Congress of Entomology Meeting 2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited Keynote presentation at International Congress of Entomology Meeting, Orlando, USA, September 2016. "Prospects for Robust Insect Resistance in Crops Using Plant Genetic Engineering".
Year(s) Of Engagement Activity 2016
 
Description International Symposium on Biotechnology and the Environment, 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact 2nd International Symposium on Biotechnology and the Environment, Pucon, Chile, 28 November - 2 December 2016 (invited plenary). "Vector/host interactions: new opportunities for protection of plants and vertebrate animals against arthropod vectored pathogens by exploiting stress related signalling"
Year(s) Of Engagement Activity 2016
 
Description Invited presentation at international conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact ca 100 people attended a scientific conference organised by the Brazilian Society for Chemical Ecology, 22-26 October 2019, in Maceio, Brazil.
Year(s) Of Engagement Activity 2019
 
Description Oral presentation at Annual Meeting of Brazilian Chemical Ecology Society (EBEQ) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Oral presentation given at 9th Meeting of the Brazilian Chemical Ecology Society (EBEQ), 4th December 2015. "Inducible Plant Signalling: Opportunities for Real Time Management of Pests".
Year(s) Of Engagement Activity 2015
 
Description Organiser of a Stakeholder Engagement Workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact 15 People attended a stakeholder engagement workshop at Embrapa-Genetic Resources and Biotechnology, Brasilia, 12th November 2019. The talk and workshop sparked questions from industry/business and increased interest in the subject area.
Year(s) Of Engagement Activity 2019
 
Description Visit by Bayer Distributors to Rothamsted; presentation given 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Industry/Business
Results and Impact Visit by Bayer French distributors to Rothamsted, 16th June 2017. Presentation given "Smart/sentinel signalling for recruitment of beneficials"
Year(s) Of Engagement Activity 2017