Mineral and vitamin deficiencies affect over one-half of the world’s population and contribute to a number of human chronic disease conditions. Economic, social and food technological processing factors can contribute to lower nutrient intake. Progress has been made to overcome those nutritional deficiencies in human body mainly through supplementation and food fortification.
Another option to commercially marketed products is biofortification: a strategy aimed at developing nutrient- and vitamin-dense crops through conventional breeding or biotechnological engineering.
Determining how plants regulate mineral nutrient uptake from the rhizophere, as well as transport and allocate nutrients to organs can have significant implications for human health. With the knowledge of genes governing mineral homeostasis and pathways of nutritional importance, it is possible to develop biofortification strategies. This requires a multidisciplinary research approach with funding strategies to support such research and to ultimately disseminate crop varieties with improved nutritional characteristics. One of Christian Hermans’ research theme is on magnesium, which is a disregarded element both in human and crop nutrition (a paradox in view of the essential roles it plays in every cell of every organism). He is aiming at identifying key genetic controls, which could ameliorate magnesium content of plant tissues.
Which are the approaches in basic research? When will biofortified crops be available? Will be a change in consumer habits?
ResearchTalks Vol. 5 - Crop biofortification: a solution to human malnutrition?
1. Crop biofortification: a solution to
human malnutrition?
Christian Hermans
chermans@ulb.ac.be
Lab. Plant Physiology and Molecular Genetics – Université Libre de Bruxelles
13th May 2013
2. CO2
H2O
Light
= The relationship between plants and all chemical elements other than
carbon, hydrogen, and oxygen in the environment.
Photoassimilates
Structural elements
C, H, O
Mineral elements
Major :
N, P, K, Ca, Mg, S
Oligo :
Fe, Zn, Mn, Cu,
B, Mo, Cl, Ni
3. Because of the constant fluctuations in the environment, the plant has
to control the ideal concentration of each mineral within its tissues.
Absorption
Translocation
Storage and re-
allocation
Understanding mineral homeostasis of plants
can have impact on:
(i) the environment
Developing sustainable agriculture
(ii) the human health
Increasing nutritional value of crops
4. Human health: Increasing daily mineral and vitamin uptake
Fortification
Equilibrated diet Supplementation
Biofortification
Increasing mineral and vitamin
concentration in edible portions
of crops through fertilization,
conventional breeding or
transgenesis to overcome
deficiencies in human body.
5. Malnutrition
Condition resulting from inadequate diet or from inability to absorb or
metabolize nutrients. Under nutrition = insufficient, Over nutrition = excess
nutrient and/or calories intake
Evidence on under and over nutrition
Prevalence of undernourishment in developing countries has decreased :
23 % (1990) 15% (2012)
Prevalence of over nutrition is increasing in nearly all countries, including low-
income countries where it coexists with high rates of under nutrition.
Hidden hunger
Micronutrient deficiency is a form of malnutrition. Prevalence of vit. A, Fe, Zn
and I deficiencies remains around 30% for populations in developing countries.
Dublin Conference on Hunger
· Nutrition · Climate Justice
April 11-12 2013
http://www.pim.cgiar.org/food-security-futures-conference
6. World Health Organization (WHO)
children < 5y prevalence data
Global prevalence of micronutrient deficiencies
http://www.harvestplus.org
7. First biofortified crops being disseminated:
Saltzman et al. (2013) Biofortification: Progress toward a
more nourishing future. Global Food Security 2: 9-17.
High-iron pearl millet in India
New Delhi The government plans to link a new class of crops,
called bio-fortified crops, to the ongoing Rs.6,000 core National
Food Security Mission. March 1st 2013
High-iron bean in Rwanda
New varieties of climbing beans with higher levels of iron or zinc
have been introduced to Rwanda. April 27th 2012
Orange sweet potato in Uganda
A variety of sweet potato, bred to contain more vitamin A, could prove a useful
tool in tackling nutrient deficiency in parts of Africa. August 12th 2012
Nature
8. Vitamin
= Retinal
β-carotene (carotenoid pigment) is most important as the
precursor of vit. A in the human diet.
Vit. A deficiency leads to death from serious illness for as many as
250,000 children each year (WHO).
9. Natural genetic variation in lycopene epsilon cyclase
tapped for maize biofortification
Carlos E. Harjes et al. (2008) Science
T. Rocheford
Early signs of
acceptance for
orange sweet potato
Jan 2009, Harvest
Plus
Mozambique,
Uganda
Researchers are
breeding staple crops
with added
micronutrients early
signs from the field
indicate that both
farmers and families
are willing to accept
them. The process is
furthest along with
orange varieties of
sweet potato that
are rich in provitamin
A.
Introduction of orange
sweet potato in rural
Uganda results in increased
vit. A intakes among
children and women.
Hotz et al. (2012) J. Nutr.
10. Golden rice
(Science 2000, Nature Biotech 2005)
Addition of β-carotene biosynthesis
genes through genetic engineering.
1
2
Although developed as a humanitarian
tool, it has met with opposition from
environmental and anti-globalization
activists.
= Pandora's Box to more widespread use
of GMOs
11. Iron
Anemia = decrease in number of red blood cells or less than the
normal quantity of hemoglobin in the blood.
Anemia is one result of advanced-stage iron deficiency.
2 billion people – over 30% of the world’s population – are anaemic
(WHO).
Fe
12. Increasing iron content in rice grain
Co-ordination
between effective Fe
uptake by the roots,
effective
translocation within
the plant, storage in
the endosperm and
bioavailability upon
human ingestion
2-3x Fe content
Introduction of multiple iron homeostasis genes
Bhullar & Gruissem (2013) Biotechnology Advances 31: 50-57
OsYSL2, Ferritin
Phytase
Metal chelator nicotianamine
IRT1
13. Science 314: 1295
- 1298 (2006)
Synchrotron x-
ray
fluorescence
microtomogra
phy of
Arabidopsis
seeds
Fe is localized
in pre-vascular
tissues of the
embryo.
A mutation in
a vacular iron
transporter
(VIT1) modifies
Fe distribution
= mutant= wild type
14. What sea water, fire work,
flash light bulb, Hiroshima
bomb and a regional unit
of Greece have in
common?
Mg
15. Mg
Mg-ATP
Mg and plant yield
Verbruggen and Hermans (2013) Plant & Soil
Importance of magnesium for living organisms
Mg
Chlorophyll
0
10
20
30
40
50
60
[Mg] in plants impacts on human health
> 2/3 population (W. societies) do not meet the
estimated average requirement for Mg
Reviewed in Hermans et al. (2013) Metallomics
Under-recognized electrolyte disorder
Mosby, 2006
55%
25%
20%
Percent of US population
meeting Mg recommanded
daily allowance (RDA)
> < << RDA
16. • To exploit induced and naturally occurring mineral content
variation to identify genes involved in Mg homeostasis.
Study of magnesium homeostasis in plants
Arabidopsis thaliana Brassica species
Arabidopsis genome < Brassica genome
Synteny
Transfer of genetic markers for higher Mg content
17. Hermans &
Verbruggen, 2008
Yo
Sha
Identification of natural
accessions with contrasted Mg
content: 50% difference between
Yosemite (Yo) and Shadara (Sha)
populations.
Uncovering genes and gene
network regulating Mg content :
Linkage and genome wide
association mapping.
Natural Mg
content variation
Baxter et al. (2012) Plos ONE
18. Biofortification = research aiming at increasing nutritional quality of plant
products, but not presented as a new panacea, but only as a
complementary approach, cheap and durable.
> $ 1 billion spent on supplementation and/or fortification per year.
The International Programme on the HarvestPlus biofortification costs $ 13
million per year, a drop of water compared to other approaches!
Crop genetic improvment technologies can only be part of the solution to
malnutrition but it is unwise to exclude any validated tool (EASAC, 2013).
Malnutrition is to a great extent rooted in political, economic and cultural
issues that will not be solved by the agricultural sector only.
Is biofortification a solution to malnutrition ?
19. 1.Bundled micronutrient interventions to fight hunger
and improve education
2. Expanding the Subsidy for Malaria Combination Treatment
3. Expanded Childhood Immunization Coverage
4. Deworming of Schoolchildren, to improve educational and health outcomes
5. Expanding Tuberculosis Treatment
6. R&D to Increase Yield Enhancements, to decrease hunger, fight biodiversity destruction, and lessen
the effects of climate change
7. Investing in Effective Early Warning Systems to protect populations against natural disaster
8. Strengthening Surgical Capacity
9. Hepatitis B Immunization
10. Using Low‐Cost Drugs in the case of Acute Heart Attacks in poorer nations (these are already
available in developed countries)
11. Salt Reduction Campaign to reduce chronic disease
12. Geo‐Engineering R&D into the feasibility of solar radiation management
13. Conditional Cash Transfers for School Attendance
14. Accelerated HIV Vaccine R&D
15. Extended Field Trial of Information Campaigns on the Benefits From Schooling
16. Borehole and Public Hand Pump Intervention
If you had $75bn for worthwhile causes, where
should you start?
16 investments worthy of investment (in descending
order of desirability):
20. FOOD Mg (mg) % daily value
Cashews, dry roasted, 1 oz (28.3g) 75 20
Soybeans, ½ cup (~250ml) 75 20
Spinach, ½ cup 75 20
Potato, baked w/ skin 50 15
Peanuts, dry roasted, 1 oz 50 15
Blackeyed Peas ½ cup 45 10
Rice, ½ cup 40 10
Lentils, ½ cup 35 8
Avocado, ½ cup pureed 35 8
Chocolate milk, 1 cup 33 8
Banana 30 8
U.S. Department of Agriculture's Nutrient Database