This document summarizes research on developing and regulating a genetically modified late blight resistant potato variety for release in Uganda and other parts of East Africa. It discusses what is already known about potato and GM crops based on existing research. It then outlines the key studies and data needed to assess the GM potato variety, including evaluating its food safety, characterizing the genetic modification, assessing the new trait's efficacy and environmental impacts, and estimating the overall costs. The goal is to determine the essential information and studies required to properly evaluate and regulate the GM potato for cultivation and consumption in the region.

1. A P A , A d d i s , E t h i o p i a
Marc Ghislain
Regulating GM late blight resistant potato
what do we really need to know?

2. Researchers:
• Magembe E., Makoko I., Njoroge A., Forbes G., Ghislain M. @ BecA-CIP,
Kenya
• Rivera C., Roman, M., Gamboa S., Lindqvist-Kreuze H., Kreuze J. @
ABL-CIP, Peru
• Arinaitwe A., Kiggundu A., Barekye, A., Baguma, G. @ KaZARDI-
NARO, Uganda
Partners:
• USAID project ‘Feed the Future Biotechnology Potato Partnership for
Indonesia and Bangladesh’ MSU-Simplot-ICABIOGRAD-BARI
Sponsor:

3. What we already know about potato?
• Domesticated from wild relatives about 6,000 years ago.
• Farmers, then breeders have selected natural variants and
progeny from wild relatives.
• Late blight resistance is not a new trait, novelty is its
expected durability
• Billions of consumers have enjoyed for 300 years, all over
the world, potato products that are safe under appropriate
uses using varieties with low glycoalkaloid content.
The potato has a SUPERB record of food
security, food safety, and is environmental-friendly

4. What do we know about GM crops?
• 1996 – 2016 represents two decades of cultivation
• > 10% total arable land by 18 million farmers in 28
countries (90% of them small-holders)
• Not a single scientifically-proven ill effect on health or the
environment
• Benefits driving adoption
Klumper W, Qaim M (2014) A Meta-Analysis of the
Impacts of Genetically Modified Crops. PLoS ONE
9(11): e111629. doi:10.1371/journal.pone.0111629
GM crops have a SUPERB record of safety

5. But skepticism persists
A Pew Research Center study on science literacy, undertaken in cooperation with the
American Association for the Advancement of Science (AAAS), and released on January 29,
2015:
• 88% of scientists believe
genetically modified foods
are safe, while 57% of the
public believes that GM food
are unsafe
• Risk assessment and regulatory approval
• Stewardship of released GM products
• Fact-based communication

6. 1- Assessment of foods from GM crops
König et al., 2004
• Concept of substantial equivalence – case-by-case
• Existing methods + New methods

7. From framework to our case
One transgenic event with R genes introduced into one
locus of the potato variety X which has extreme resistance
to late blight disease for release and cultivation by potato
farmers in the potato producing regions of Uganda.

8. Crop and parental cultivar
Global, EAC, and Uganda
• Background on the crop: taxonomy, center of origin and diversity,
distribution, reproduction, crossable relatives, naturalization
• Common production system: seed tuber, no botanical seeds,
growth cycle, harvest, storage, volunteer
• Uses and consumption: qualities, fresh, processed, industrial
processing, products, and relative importance
• Recipient variety: agronomic, qualities, uses and cultivated area
• Impact of late blight disease: potato area affected, pathogen cycle
and diversity, losses due to LB disease, cost of fungicide, health
impacts, environmental impacts.
• Benefits of LBr variety: ex-ante socio-economic studies, health
and environmental impacts, change in production systems & uses
and consumption.

9. Genetic modification
• Description of the wild relatives: Solanum bulbostanum (Mex)
and S. venturii (Arg), tuber-bearing Solanum, crossable, part of
gene pool accessible to and used by breeders
• LBr genes: RB, Rpi-blb2, Rpi-vnt1.1 unmodified, genomic fragment
containing the functional genes
• Plant transformation method: vector modified pCAMBIA,
selectable marker gene nptII (the same as the one used in other
released GM crops), Agrobacterium tumefaciens protocol
• Characterization of the genetic modification: single copy, no
backbone vector sequence, all 3 R genes fully functional, flanking
sequence non-coding or regulatory sequences, stable over
generations
nptII
LB RB
Rpi-vnt1.1 RB Rpi-blb2
1
25
1,941
2,206
6,515
6,521
12,550
12,562
18,307
18,585

10. Products of the genetic modification
• R proteins:
• 1,000 R-gene analogues in potato, RB in Kathadin (GM,
under release), Rpi-blb2 in Toluca (conv. var.), Rpi-vnt1.1
in Russet Burbank (GM, released in US)
• Gene expression of the R genes, RTqPCR on leaves
under infection / no infection, stems, roots, and tubers
• R proteins induced under pathogen attack, activated by
pathogen effectors, it is a trigger of a hypersensitive
reaction leading to cell death around the pathogen,
bioinformatics analyses
• Unstable outside plant cell, barely detectable, intractable
protein, history of safe use, alternative testing needed

11. Evaluation of food / GM crop
• Nutritional composition of the best event: proximates, vitamins,
minerals, amino acids, and glycoalkaloids in comparison with
untransformed to show not significantly different, and stable by
locations and years.

12. 2- Assessment of the new trait
• Multi-location trials: 3 locations, and 2 seasons as minimum to
collect all data on trait efficacy, agronomic performances, and
environmental unintended effects
• New trait efficacy:
• LB disease score: lesions, sporulation
• Pi strain characterized
• Agronomic trait equivalence:
• Yield
• Maturity
• Dormancy – Emergence
• Any other essential traits as requested for conventional variety
release

13. 3- Assessment of environmental impacts
1. Naturalization: long experience of potato
cultivation, no abandoned tuber seed, no feral
state, volunteer for 4 years, LBr is a common trait
of many released varieties (not durable)
Survival (%) of
conventional (blue)
and GM crops (red).
Crawley et al., 2001

14. 3- Assessment of environmental impacts
2. Transgene flow: no wild relative sexually compatible in Africa, no
new varieties generated by natural hybridization, less likely with
modern varieties, farmers preserve varietal identity, use of seed
tuber for planting
This was never observed with conventional varieties, farmers
maintain variety identity (discard off-types) and use seed tubers. LB
resistance variety is not expected to behave differently
Gene flow between potato varieties could result in
a new hybrid potato if:
1. The varieties are fertile
2. Both have overlapping flowering time
3. They are grown at proximity <20 m
4. The environment has pollinator insects
5. Seeds germinate
6. Hybrid is viable
7. Farmer adopts the hybrid

15. 3- Assessment of environmental impacts
3. Impact on biodiversity: past experience show this trait is neutral,
reduced fungicide impact on the environment,
4. Non-target organism impact: no such observation, no scientific
bases due to effector – R gene specificity, R proteins are not
toxins, low quantities and ephemeral
5. Comprehensive field observations: during M-CFT, regular
observations of growth of the GM vis-à-vis the non-GM potatoes
(plant growth, flowers and berries production, volunteers,
arthropods, pests, and diseases)

16. • GM programs are too expensive for non-profit institutions?
• Literature: 1 million to 130 million, but has little verifiable evidences
• Our study is based on real costs and estimates for two independent
initiatives for production and regulatory dossier development for 1 GM
LBr variety in one country: cost is around 1.5 million US$
• Timeline is 8-9 years, can be reduced to 6 after first product developed
and released
Cost and timeline of the regulatory phase
Schiek et al, 2016

17. East African community:
• 5 countries >48% SSA potato production
• Variety registration harmonized and facilitated
• Varieties are grown across borders
• Tubers cross borders
1. Desirable to release more than one LBr variety to give more
options to farmers, 4-5 varieties for the EAC
2. Desirable to release in more than one country, 4-5 countries
Caveats
If so, cost may be closer to 10 million for producing and
releasing GM varieties in EAC that are resistant to a disease
causing loses of up to 2.75 billion USD/year in SSA

18. 1. Ex-ante socio-economic assessment of the release of LBr
potato variety in Uganda, in other EAC.
2. Insertion site and T-DNA structure and stability
3. R gene expression w/o pathogen during plant development
4. Alternative testing of food from the LBr tubers
5. Nutritional composition in 3 locations for 2 seasons
6. Trait performance in 3 locations for 2 seasons
7. Resistance management (enhancing durability)
8. Agronomical performance in 3 locations for 2 seasons
9. Behavioral study on plant development, susceptibility to pests
and non-LB diseases, and relevant NTO
What do we really need to know?