UK - Brazil partnership on the chemical ecology of crop-plant/rust-pathogen interactions for underpinning novel crop protection strategies

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


Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
Description This project brought together UK (Rothamsted Research) and Brazilian (Embrapa-Soybean) expertise in a new partnership to elucidate the chemical ecology of soybean and Phakopsora pachyrizi interactions, for the development of novel sustainable control strategies against rust pathogens in Brazil, and eventually for other rusts affecting UK agriculture.
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 infection of Brazilian soybean cultivars, Glycine max, available from the Embrapa germplasm bank, with Phakopsora pachyrhizi, the causative agent of Asian Soybean Rust, elicited modification of volatile organic compound (VOC) production at a very early stage (1-3 days) after infection. We investigated the ability of identified volatile metabolites to prime defence in uninfected soybean plants against P. pachyrhizi infection.
We tested our hypothesis that modification in the emission of volatile secondary metabolite production upon P. pachyrhizi infection is a due to a change in metabolic flux in secondary metabolite biosynthesis, resulting in changes in levels of other secondary metabolites. Extraction of plant tissue and analysis using HPLC, LC-MS and comparison with authentic samples of compounds suggested a statistically significant increase in the production of phytoalexins known to possess antibiotic activity against plant pathogens. These compounds also possess antixenotic activity against stink bugs, the major insect pest of soybean crops in Brazil, and upon testing the hypothesis that our plant stress related elicitor cis-jasmone provides protection in soybean pods against the seed-sucking stink bug pest, Euschistus heros, we showed that treatment leads to an increase in the levels of defensive compounds in immature soybean seeds similar to those increased by P. pachyrhizi infection.
Our hypothesis that production of the identified secondary metabolites is via specific biosynthesis pathways was tested by using next generation sequencing (comparative RNA-seq) to show differential expression of putative biosynthesis genes in soybean upon P. pachyrhizi infection. The challenge will be to understand fully the underlying mechanisms of soybean / P. pachyrhizi infection at the genetic level, by confirming of the role of the implicated biosynthesis genes in metabolite production in order to link the identified promoter sequences for the upregulated genes to genes responsible for biosynthesis of optically visible natural products eg anthocyanins.
The collection and analysis of volatile compounds and phytoalexins from soybean was facilitated by two separate visits (six months, six weeks) of Embrapa-Soybean scientists to Rothamsted Research. Skills for sample collection and analysis were transferred to Embrapa for further development of the project in Brazil.
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 Chemical Ecology of Crop/Rust Interactions 
Organisation Brazilian Agricultural Research Corporation
Country Brazil 
Sector Public 
PI Contribution Principal Investigator
Collaborator Contribution Co Investigator
Impact 1 Peer-review publication
Start Year 2012
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 Oral presentation at IUPAC Pesticide Chemistry Congress, San Francisco, USA 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Oral presentation given at 248th ACS National Meeting, IUPAC Pesticide Chemistry Congress, San Francisco, 12th August 2014. "New Chemical Ecology Based Opportunities for Agriculture in the Face of Global Climate and Population Challenges".
Year(s) Of Engagement Activity 2014