Nematode resistant plantain for African subsistence growers

Lead Research Organisation: University of Leeds
Department Name: Ctr for Plant Sciences

Abstract

The former secretary general of United Nations, Kofi Annan, called for a uniquely African Green Revolution in 2004. The need is to counter severe under-nourishment in nearly one third of the sub-Saharan African population. He and eight leading economists including three Nobel laureates recognised the potential of biotechnology to enhance food security. A key issue is African dependence on crops such as plantain. It is not often studied by plant breeders in the developed world. Plantain and other cooking forms of banana provide 27% of the daily calorie intake of Ugandans and 25% of the carbohydrates of 60 million people in West Africa. Most plantains are sterile and produce no seeds. This hampers their improvement by conventional plant breeders. This sterility enhances the biosafety of plant biotechnology involving this crop. The need is considerable as plantain is highly vulnerable to severe crop loss from diseases and pests. This issue has been highlighted by news media. This project will provide nematode resistant plantains for Africa. Nematodes are simple thread-like animals of less than 1mm in length that feed in plant roots. Experiments in several African countries show their abundance often results in yield losses of 70% to plantain. Chemical control of nematodes is currently required for most plantations of dessert banana. We will reduce losses to banana with an approach that provides an alternative future to increased pesticide use. Three bases for providing resistance will be used in combination to provide high levels of durable resistance in the field. Two approaches are available 'off the shelf'. All draw on outputs from other BBSRC funded research and build on previous work for DFID. The approaches offers a high level of environmental and food safety. Scientists in Uganda will produce all the new plants so enhancing the ability of that country to complete such work. Levels of resistance will be determined that prevent nematodes from damaging plant growth. All necessary information will be collated for the Uganda national biosafety committee to consider consent for field trials. This has already been granted for other banana plants. The project links to other work providing resistance to fungal and bacterial diseases for plantain and bananas. The combination of benefits can be delivered sooner by biotechnology than possible by conventional plant breeding. The work will demonstrate that plant biotechnology can benefit the poor in Africa. It meets a real need for nematode control that is recognised by its farmers. Nematode resistance is required for other subsistence crops of Africa that will be addressed later using the same technology. The project avoids the general concern of some that biotech crops require dependence of the developing world on the products, patents or licences of biotechnology companies. The partners of this project have a long-established commitment to royalty-free biotech crops for Africa. The work seeks to establish that public research for public good can develop benefits for the poor in Africa in support of the Millennium Development Goals. Plantain represents a biosafe crop on which to develop the necessary capacity. We seek to enable African science to support all aspects of biotechnology and biosafety that can support national aims to enhance food security. In-country capacity in plant biotechnology is necessary before African countries can make realistic assessments of what they can and cannot achieve that meets national needs.

Technical Summary

The work is based on Agrobacterium-mediated introduction of genes to plantain by a novel technique of apical meristem transformation. This avoids slow regeneration of plants from single cells that may result in unwanted somaclonal variation. The approach has been developed by the co-applicant within Africa. Initial work will use constructs providing expression of a maize cysteine proteinase inhibitor already present in the food of Africans. It prevents nematodes from utilising their dietary protein without harmful effect on humans and controls a wide range of plant nematodes including those that damage plantain. Toxicological studies establish a margin of exposure is >2000 fold when root specific promoters are used to deliver a cystatin. UK field trials have established no substantial adverse effect either on invertebrate associates of a potato crop above ground or on soil communities. The cysteine proteinase inhibitor will be stacked with a non-lethal, synthetic peptide that limits root invasion by nematodes. The work will also adapt other research for BBSRC that is expressing a double stranded RNA in plants. This results in the silencing of a gene that the nematode requires to survive or develop in plants. This effect was first reported in detail for a nematode and resulted in the award of the Nobel Prize for Medicine for the advance it provides. In the context of the current work, the lack of new protein expression in plants overcomes the concerns of expression of even biosafe, novel plant proteins in biotech crops. The levels of resistance required to prevent nematode mediated growth suppression of plantain that lead to yield loss will be determined. This and other information will be collated and permission sought for field trials in Uganda. All the objectives of the work combine to enhance the capacity for Uganda to develop biotech crops in country to meets its national needs and objectives.

Publications

10 25 50
 
Description 1) Nematode resistant plantain was developed in Africa using novel transformation and technology developed in Leeds.

The new defences were developed at University of Leeds and used for the improved Agrobacterium-mediated transformation of plantain cultivar cv Gonja at IITA in Uganda. Currently the best maize seed cystatin line provided 89 ± 6% resistance in the glasshouse and a second technology involving a deterrent peptide 84 ± 12% resistance to the principal nematode pest of banana (Radopholus similis). The approach is effective against at least three banana nematode species and not just one nematode species or pathotype as with most sources of natural resistance in crops. This is an important point as most resource poor farmers are unaware of nematodes and lack the extension advice needed to distinguish species.

This level of resistance has now been shown to occur in two contained field trials in Uganda using lines selected from the glasshouse challenges.



2) RNA interference (RNAi) was shown to have potential for nematode resistance without novel protein expression.

This approach targets a nematode gene, preventing its expression to the detriment of the parasite. Several genes have been targeted for RNAi based on a high sequence homology among economic banana nematodes so limiting the number of dsRNA molecules that plantain must express to target all damaging nematode species. Quantitative PCR has established a large reduction in normal expression levels after uptake of defined dsRNA molecules by R. similis. In addition a bioassay has been established that allows continual dosing of feeding nematodes. The multiplication of R. similis was severely reduced with the most effective gene causing an 87 ± 2% reduction in multiplication of this nematode. Therefore we have identified a number of genes of high promise for a future RNAi-mediated programme for nematode control.



3) The level of resistance achieved is sufficient to prevent nematode-induced growth suppression of plantain.

A field trial was carried out with untransformed cultivars over c700 days (two cropping cycles) of plantain in Uganda. It demonstrated, for the first time, that measuring Leaf Area Index (LAI) by digital hemispherical photography is a rapid, non-destructive approach for assessing growth of plantain and banana crops. The losses recorded in the trial were of the order of 37% after only two cropping cycles with the reduced vigour of infected plants being progressive. It is predicted that these losses will be prevented by the new technology. These results also emphasise that nematode control is a high priority for future food security of those Africans that are dependent on bananas and plantains within SSA.



4) The capacity for plant biotechnology in Uganda was enhanced based around a highly biosafe crop species.

Training was provided in Leeds for three IITA and Uganda scientists in various techniques associated with the work programme. Critical biosafety and other information was provided to the Ugandan authorities for the now granted contained field trial of the plants that was planted in 2012.
Exploitation Route These plants will be progressed to small-scale famers. This may also involve intermediate small business responsible of generation of tissue culture plants. Discussion on this is likely in May-July 2012 in Leeds and possibly Uganda with Bio-Plus Strategies International (BIOPSTRA) and USAID. The plants will be field trialled at a contained site and then developed jointly by University of Leeds/ International Institute of Tropical Agriculture (IITA) and National Agricultural Research Organisation of Uganda (NARO). A joint exploration agreement has been signed by these three parties. Subsequent steps will involve field trail at tertiary sites before consideration is given to providing them to farmers in Sub-Saharan Africa. Progress is partially dependent on future funding by DFID and/or BBSRC.
The future of the project beyond ABSPII is currently being considered. If the work continued it will centre on translation of findings to uptake by small farmers in Uganda.

The not-for-profit organisation African Agriculture Technology Foundation has expressed initial interest in supporting the uptake pathway once the plants have been shown to be as effective in the field as in the glasshouse to-date which is likely.

The findings have also underpinned the decision of USAID ABSPII program to a initiate two confined field trials of banana with the same technology. They and the Ugandan Government banana biotechnology lab. (NARL) are also supporting the trial BBSRC generated plantain plants through the 1st ratoon crop.
Sectors Agriculture, Food and Drink

 
Description 1. The success of the glasshouse trials (see Roderick et al 2012 cited in the profile) led to IITA funding a confined field trial in Uganda with the plantains generated in the BBSRC funded research. 2. Some BBSRC lines showed very high levels of resistance of the mother plantain crop in the confined field trial (see Tripathi et al 2015 cited in the profile). 3. Success led our collaborator (Dr Tripathi) to place the genes at the centre of her application to the Bill & Melinda Gates Foundation to transform African Yam. The grant was awarded in two parts. Dr Tripathi has demonstrated an ability to transfer yam in the first part, the expectation is that nematode resistant yam will be developed in collaboration with U. Leeds. 4. Success within the BBSRC grant underpinned the decision of the USAID ABSPII project on banana improvement to also carry out confined field trials using the same defences developed for plantain. Nematode resistance has also been achieved in a dessert banana Sukali Ndizi in a trial in run 2012-2014 and is being developed for East African Highland banana in a further trial being planted in 2016. 5. The success of the banana field trial and those in UK with potato (other BBSRC grants), has led to increased interest in the defences in our international collaborations with USDA, IARI, India and China Seeds. 6. The collaboration with USDA using technology developed in this and other BBSRC grants on Easter Lily (which has severe nematode problems) has now been published (see publications) and received much grower support in USA.
First Year Of Impact 2014
Sector Agriculture, Food and Drink
Impact Types Economic,Policy & public services

 
Description Biotechnology and Pest Resistance Breeding
Geographic Reach Africa 
Policy Influence Type Influenced training of practitioners or researchers
Impact This seminar on 2/09/2014 to Biosafety regulators, researchers and other stakeholders in Africa on the uptake of GM crops with resistance to pests particularly nematodes. Thisis part of USAID ABSPII providing information to stakeholders on the benefits of banana biotechnology ahead of the case being made for their uptake in Uganda. Nematode resistance was developed with BBSRC funding including BB/F004001/1
 
Description GM Science Update: A report to the Council for Science and Technology
Geographic Reach National 
Policy Influence Type Citation in other policy documents
 
Description Genetic Modification information for parliamentarians
Geographic Reach National 
Policy Influence Type Gave evidence to a government review
URL http://www.scienceinparliament.org.uk/wp-content/uploads/2013/09/sip67-1.pdf
 
Description Molecular Approaches to Controlling Nematodes, with Emphasis on Banana
Geographic Reach Africa 
Policy Influence Type Influenced training of practitioners or researchers
Impact This seminar on 20/09/2014 to researchers and other stakeholders in Africa on the uptake of GM banana crops with resistance to pests particularly nematodes. This is part of USAID ABSPII providing information to stakeholders on the benefits of banana biotechnology ahead of the case being made for their uptake in Uganda. Nematode resistance was developed with BBSRC funding including BB/F004001/1
 
Description RNAi technologies and the safety (bio-and food safety) concern, current situation analysis and the future
Geographic Reach Africa 
Policy Influence Type Influenced training of practitioners or researchers
Impact This seminar on 20/09/2013 to researchers and other stake holders in Africa on the uptake of GM crops with resistance to pests based on RNAi technology. This was part of a seminar series run for the USAID ABSPII providing information on available technologies for pest control in banana. Nematode resistance with RNAi has been developed with BBSRC funding including BB/F004001/1
 
Description Regulation and biotechnology product development
Geographic Reach Africa 
Policy Influence Type Influenced training of practitioners or researchers
Impact A seminar was provided in Kampala on 3/09/2014 to Biosafety regulators, researchers and other stakeholders in the uptake of GM crops. It is part of USAID ABSPII's wish to inform Uganda of the needs for early and biosafe uptake of transgenic banana for food security in that country. A document based on the seminar will be provides to the Uganda partners (NARL) in early 2015 for use in their interactions with the National Biosafety Committee of Uganda.
 
Description Nematode Resistance by Molecular Breeding of East African Highland Banana
Amount $137,788 (USD)
Organisation United States Agency for International Development 
Sector Public
Country United States
Start 10/2014 
End 09/2015
 
Description Nematode Resistance by Molecular Breeding of East African Highland Banana
Amount $133,000 (USD)
Organisation United States Agency for International Development 
Sector Public
Country United States
Start 10/2015 
End 09/2016
 
Description Nematode Resistance by Molecular Breeding of East African Highland Banana
Amount $113,853 (USD)
Organisation United States Agency for International Development 
Sector Public
Country United States
Start 10/2013 
End 09/2014
 
Description Nematode Resistance by Molecular Breeding of East African Highland Banana
Amount $109,756 (USD)
Organisation United States Agency for International Development 
Sector Public
Country United States
Start 10/2012 
End 09/2013
 
Description Nematode Resistance by Molecular Breeding of East African Highland Banana
Amount $88,000 (USD)
Organisation United States Agency for International Development 
Sector Public
Country United States
Start 10/2011 
End 09/2012
 
Description BBSRC profile "Great British Science Pioneers" 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Hopefully raised profile of BBSRC's impact from funding

The impact would accrue with BBSRC
Year(s) Of Engagement Activity 2014
URL http://www.bbsrc.ac.uk/news/people-skills-training/2014/140804-f-gb-bioscience-pioneers-howard-atkin...
 
Description BBSRC website profile of Howard Atkinson 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Undergraduate students
Results and Impact Benefit accrued partly to BBSRC.


The Plant Nematology group has recruited very able PhD students in recent years with the high profile of our work and its application to the developing world being one aspect of the interest of young scientists
Year(s) Of Engagement Activity 2011
URL http://www.bbsrc.ac.uk/news/people-skills-training/2011/110228-f-profile-howard-atkinson.aspx
 
Description Bananas become ripe GM target, 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Financial Times Magazine, Published 4th February 2012



Article by FT journalist arising from BBSRC report (http://www.bbsrc.ac.uk/news/food-security/2011/111005-f-defeating-nematode-worms-gm-bananas.aspx )summarising this research Article

no actual impacts realised to date
Year(s) Of Engagement Activity 2012
URL http://www.bbsrc.ac.uk/news/food-security/2011/111005-f-defeating-nematode-worms-gm-bananas.aspx
 
Description Current and Potential Biosafety Issues for RNAi Based Control of Banana Nematodes 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact The talk within a capacity building course funded by USAID ABSPII helped motivate young Ugandan scientists working at Ugandan government labs. in the field of plant biotechnology.

I received two request for PhD training in U. Leeds however the high level of UK fees resulted in neither person coming to the UK.
Year(s) Of Engagement Activity 2013
 
Description Newspaper article in Financial Times Magazine Published 4th February 2012. Bananas become ripe GM target 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Contribution to benefits that GM crops can bring

None
Year(s) Of Engagement Activity 2012
URL http://www.ft.com/cms/s/2/5fa2963e-4c86-11e1-b1b5-00144feabdc0.html#axzz2YSRe1p
 
Description What the Green Movement got wrong 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Channel 4 investigation and panel debate about incorrect stances on GM crops and other issues of the green movement. Atkinson was the expert panel member on GM crops for the developing world building on the achievements of the BBSRC grant.

no actual impacts realised to date
Year(s) Of Engagement Activity 2010
URL http://www.channel4.com/programmes/what-the-green-movement-got-wrong/episode-guide
 
Description Why genetically modified crops are good for us 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact An article: "The case in favour of GM crops" using the BBSRC funded research at Universiity of Leeds on potato and banana as key examples. It was written by an award winning journalist, Article publshed in the Sunday Times Magazine

no actual impacts realised to date
Year(s) Of Engagement Activity 2010