A description of the history, variation in methods/ approaches for biofortifying rice, benefits and challenges faced with biofortified rice and consequences for future generations..

1. BIOFORTIFICATION OF RICE
FOOD BIOTECHNOLOGY
PRESENTATION
BY
EUGENE MADZOKERE
4.1 Biotech Undergrad Student
Chinhoyi University of Technology (Zim)

2. PRESENTATION OUTLINE

INTRODUCTION:
-What is Biofortification?
-Reason for Rice Biofortification
-Micronutrients Biofortified into Rice
-Methods used to Biofortify Rice
-Where Biofortification is done?


TYPES OF RICE BIOFORTIFICATION IN DETAIL:
CONCLUSION:
Advantages & Disadvantages?

REFERENCES:

3. INTRODUCTION:
Biofortification: “The development of
nutrient dense staple crops using the best
traditional breeding practices and modern
biotechnology”.
 It makes foods more nutritious as plants
are growing rather than having nutrients
added to plant foods during processing.


4. Reason for Rice Biofortification




Rice is a staple food crop for more than one
billion poor people
The Rice endosperm (starchy & most edible
part of rice seed) is deficient in many
nutrients including vitamins, proteins,
micronutrients, EAAs, etc.
The Aleurone layer of dehusked rice grains is
nutrient rich but is lost during milling and
polishing
Unprocessed rice becomes rancid i.e. smelly
or unpleasant in taste

5. STRUCTURE OF THE RICE SEED GRAIN

6. STRUCTURE OF THE RICE SEED GRAIN

7. Micronutrients Biofortified into Rice:

Vitamin A (Retinol) – Golden Rice

Iron

Zinc

Vitamin B9 (Folic acid/ Folate)

Glycinin

8. Methods used for Rice Biofortification:

Agrobacterium mediated gene transfer

Particle gene gun method

9. Where is Biofortification done?
India
 China
 USA
 Phillipines
 Vietnam
 Bangladesh
 Japan


10. Vitamin A Rice Biofortification:







Done by Prof. Ingo Potreykus & Dr. Peter Beyer
Because the rice endosperm lacks vitamin A and;
Vitamin A deficiency causes night blindness; impaired
vision, epithelial tissue integrity, immune response;
hematopoiesis & skeletal growth mostly in young
children aged 1-5 years old
Biofortification involved introduction of three genes
in rice grain via Agrobacterium tumefaciens:
1. phytoene synthase (psy) – daffodil (Narcissus
pseudonarcissus)
2. lycopene B - cyclase (crt) – daffodil (Narcissus
pseudonarcissus)
3. phytoene desaturase – bacterium (Erwinia uredovora)

11. Vitamin A Rice Biofortification:
Successful production of Golden rice 1
(GR1) and Golden rice 2 (GR2)
 GR1- yield of 1.6µg provitamin A/g in
endosperm
 GR2- higher yield of 31µg/g provitamin A in
endosperm by replacement of psy gene from
daffodil with a psy gene from maize
 72µg
of GR2 could provide the
recommended daily vitamin A allowance for
1-3 year olds, because they consume 100200g of rice per meal.


12. Vitamin A Biofortification: Engineering
The Carotenoid Biosynthetic Pathway
Phytoene synthase
GGPP (C20)
Phytoene (C40)
Phytoene desaturase (PDS)
CRT 1
C-Carotene
Zeta carotene desaturase
(ZDS)
Lycopene
Lycopene β- cyclase
B-carotene
Vitamin A

13. Iron (Fe) Biofortification of Rice:
Iron (Fe) is a redox - active constituent of the
catalytic site of heme and non-heme iron proteins
 Metabolic functions of Fe include:
1. Serving as an element in blood production
2. Serving as a component of enzymes involved in
synthesis of collagen & some neurotransmitters
3. Providing a transport medium for electrons
within the cells in the form of cytochromes
4. Being a structural component of haemoglobin


14. Iron Biofortification of Rice:
Consequences of Fe deficiency include:
1. Blood loss leading up to Sickle Cell
Anaemia
2. Causes Gastro-intestinal blood loss in
men & post-menopausal women
Normal RBC
Sickled RBC


15. Iron Biofortification of Rice:
 In the Fe-Rice Biofortification process;
1. Three genes were introduced into
a)
b)
c)
the
Japonica rice variety:
Ferritin – enhances iron storage in grains &
was expressed under an endosperm
specific promoter.
Nicotianamine synthase – was expressed
under a constitutive promoter & produces
nicotinamine
which
chelates
iron
temporarily facilitating its transport in
plants
Phytase – degrades phytate

16. Zinc Biofortification of Rice:
Zn is an important micronutrient:
1.
Critical in tissue growth, wound healing, connective tissue
growth & maintenance, immune system function,
prostaglandin production, bone mineralization, proper
thyroid function, blood clotting, cognitive functions, fetal
growth & sperm production
2.
It plays an important role in the health of skin, bones, hair,
nails, muscles, nerves & brain function.

3.
Is required for metabolic activity of enzymes (as a
cofactor) involved in repair & replacement of body cells.
4.
Its essential for cell division & synthesis of DNA & proteins

17. Zinc Biofortification of Rice:
Zn deficiency leads to:
1.Impairment of physical growth, immune
system & learning ability
2.Fetal brain cell disease & affects mental
development in pregnant mothers
3.Hindered
normal
growth
and
development in children
4.Increased risk of infections, DNA damage
& cancer


18. Zinc Biofortification of Rice:
 In the Zn-Rice Biofortification process;
• Three (3) genes of the OSNAS family
•
•
•
•
were
introduced into Japonica rice cultivar Nipponbarp
These three genes encode production of
nicotianamine (NA) - a chelator of transition
metals that facilitates uptake & transport of metal
cations including, Zn2+
Specific over-expression of OSNAS resulted in
significant increase in NA concentration and Zn
OSNAS 2 activation had 20 fold more NA & 2.7
fold Zn in polished rice grains
OSNAS 3 activation was reported to reverse
signs of Fe-deficiency when fed to anaemic mice

19. Folate Biofortification of Rice:



Folates (vitamin B9) are tripartite molecules
containing the pterin moiety, PABA, & one or
several Glutamate residues
It plays a major role in the methylation & in
DNA biosynthesis
Biofortification is achieved by overexpressing 2 Arabidopsis thaliana genes of the
pterin and para-aminobenzoate branch of the
biosynthetic pathway from a single locus

20. Folate Biofortification of Rice:
Folate biosynthesis requires the plastid
chromate pathway intermediate (PABA) &
Pterin precursor from GTP
 Rice engineered using targeted expression
of GTPCHI & ADCS to increase folic acid
biosynthesis in seeds
 Transformed plants with ADCS had 49
fold increase in levels of PABA


21. Folate Biofortification of Rice:
Folate dietary deficiency results in :
1. Neural tube defects e.g. Spina bifida
2. Cardio vascular diseases
3. Different forms of dementia
4. Megaloblastic anaemia


22. Glycinin Biofortification of Rice:
Glycinin is a lysine rich globulin protein
found in soybean seeds
 Lysine is an essential amino acid (EAA)
 Rice seed endosperm is deficient in lysine
 Glycinin accounts for more than 20%
seed dry weight & is a reserve for carbon
& nitrogen used in seed germination
 Five Glycinin genes: Gy1; Gy2; Gy3; Gy4; &
Gy5


23. Glycinin Biofortification of Rice:
Four molecular approaches that are commonly
used:
1. modifying the higher protein sequence of a major
crop protein to contain higher content of
desired EAA
2. Producing a synthetic protein rich in target EAA
3. Expressing a heterologous protein with high
content of desired EAA
4. Manipulating the expression of a homologous
protein for desired EAA
5. By increasing the pool of a specific free EAA
through metabolic engineering


24. Glycinin Biofortification of Rice:




Approach 4 was used
Biofortification involved insertion of 4
contiguous methionine residues into the 11S variable regions of the soybean Glycinin
gene corresponding to the C-terminal
regions of the acidic & basic polypeptides
Modified Met-rich soybean Glycinin gene
under control of GluB-1 promoter was
transformed using Agrobacterium tumefaciens
and expressed in rice,
5% total glycinin protein was obtained

25. Glycinin Biofortification of Rice:
Mainly introduced because it is a seed storage
protein which is lacking in the rice grain
 Lysine facilitates normal growth & development;
lowering of serum cholesterol; LDL cholesterol –
hence lowered risk of heart disease
 Effects of lysine deficiency include:
1. Hair loss or Poor growth
2. Excessive fatigue & mood changes
3. Loss of Appetite
4. Anemia
 Supplements or food sources should provide
12mg/kg body weight of lysine/day


26. CONCLUSION: Advantages of
Rice Biofortification
Advantages of biofortification of rice include:
Increase in nutritional value .i.e. bioavailable
Vitamin A & B6; Fe; Protein (glycinine) & Zn
2. Increase in yield e.g. Rice biofortified with
Glycine betaine for enhanced abiotic stress
tolerance
3. Reduced adult & child micronutrient caused
mortality
4. Reduced dietary deficiency diseases e.g.
Blindness in children, diarrhoea, anemia
5. Healthier populations with strong and quick
immune responses to infections.

1.

27. CONCLUSION: Disadvantages of
Rice Biofortification

1.
2.
3.
4.
5.
Disadvantages of biofortification of rice include:
High production costs .i.e. equipment, technology,
patenting, etc;
Potential negative interaction of biofortified rice on
other plants/ non-GM rice crops causing loss of
wild-type rice varieties
Low substantial equivalence- i.e. inability to provide
high micronutrient and protein content compared
to supplements
Poor rural populations have limited access &
resources to purchase biofortified rice
Genetic
engineering
methods
used
may
compromise immunity in humans .i.e. introduce
increased risk of allergenicity

28. REFERENCES:


Sun, S.S.M., Liu, Q.Q. (2004). Trangenic
approaches to improve the nutrional quality
of plant proteins. In Vitro Cell Development.
Biology Plants. 40: pp. 155-162
Katsube, T., Kurisaka, N., Ogawa, M.,
Maruyama, N., Ohtsuka, R., Utsumi, S., and
Takaiwa, F. (1999). Accumulation of soybean
glycinin and its assembly with glutelins in
rice. Plant Physiology. 120: pp. 1063-1073