A report about Genetic Manipulation and Host Plant Resistance

1. Reyes, Czarina Gricell
Reyes, Clark Andrei
Romero, Marielle
Salandanan, Angelica
Salazar, Isabella
GROUP 5

2. - is a process where the gene for a particular
character is introduced inside the chromosome of a
cell. When the gene for a particular character is
introduced in a plant cell, a transgenic plant is
produced. These transgenic plants exhibit
characters governed by the newly introduced gene.
- It helps in improving crop variety. It ensures
food security and insect resistant crops. It also
improves the quality and yield of crops.

3. - Is the direct manipulation of an organism's
genome using biotechnology. It is a set of
technologies used to change the genetic makeup of
cells, including the transfer of genes within and
across species boundaries to produce improved or
novel organisms.

4. are plants used
in , the of which has
been modified using genetic engineering
techniques. In most cases the aim is to
introduce a new trait to plant which does
not occur naturally in species.

5. Examples in food crops:
• resistance to certain pests, diseases, or
environmental conditions
• reduction of spoilage
• resistance to chemical treatments (e.g.
resistance to a herbicide)
• Improving the nutrient profile of the crop.
Plant tissue culture and deliberate mutations have
enabled humans to alter the makeup of plant
genomes.

6. - a collection of techniques used to maintain or grow
plant cells, tissues or organs under sterile conditions
on a nutrient culture medium of known composition.
Techniques
• The production of exact copies of plants that
produce particularly good flowers, fruits, or have
other desirable traits.
• To quickly produce mature plants.
• The production of multiples of plants in the
absence of seeds or necessary pollinators to
produce seeds.

7. • The regeneration of whole plants from plant
cells that have been genetically modified.
• The production of plants in sterile containers
that allows them to be moved with greatly reduced
chances of transmitting diseases, pests, and
pathogens.
• The production of plants from seeds that
otherwise have very low chances of germinating
and growing, i.e.: orchids and Nepenthes.
• To clean particular plants of viral and other
infections and to quickly multiply these plants as
'cleaned stock' for horticulture and agriculture.
• The first genetically modified crop plant was
produced in 1982, an antibiotic-resistant tobacco
plant.

8. Application
• A plant breeder may use tissue culture to screen cells
rather than plants for advantageous characters, e.g.
herbicide resistance/tolerance.
• Production of identical sterile hybrid species can be
obtained.
Plant Genetic Systems (PGS)
Best known for its work in the development of insect-
resistant transgenic plants. The focus of its activities is the
genetic engineering of plants
First company to genetically engineer insect-resistant
(tobacco) plants by incorporating genes that produced
insecticidal proteins from Bacillus thuringiensis.

9.  DNA transfers naturally between organisms.
 The introduction of foreign germplasm into crops
has been achieved by traditional crop breeders
by overcoming species barriers. A hybrid cereal
grain was created in 1875, by crossing wheat
and rye. Since then important traits including
dwarfing genes and rust resistance have been
introduced. Plant tissue culture and deliberate
mutations have enabled humans to alter the
makeup of plant genomes.

10.  The first genetically modified crop plant was
produced in 1982, an antibiotic resistant
tobacco plant. The first field trials occurred in
France and the USA in 1986, when tobacco
plants were engineered for herbicide
resistance. In 1987, Plant Genetic Systems,
founded by Marc Van Montagu and Jeff
Schell, was the first company to genetically
engineered insect resistant (tobacco) plants
by incorporating genes that produced
insecticidal proteins from Bacillus
Thuringensis.

11. Genetically engineered crops have genes
added or removed using genetic
engineering techniques, originally including
gene guns, electroporation,
microinjection, agrobacterium, crispr
and talen.

12. GENE GUN
“(a.k.a. biolistic) shoot”
(direct high energy
particles or radiations
against) target genes
into plant cells. It is the
common method. DNA
is bound to tiny
particles of gold or
tungsten which are
subsequently shot into
plant tissue or single
plant cells under high
pressure.

13. ELECTROPORATION
Is used when the plant tissue does not contain cell
walls. In this technique, “DNA enters the plant cells
miniature pores which are temporarily caused by
electric pulses.

14. MICRO INJECTION
Directly injects the gene into the DNA.

15. AGROBACTERIUM
TUMEFACIENS
Agrobacteria are natural
plant parasites, and their
natural ability to transfer
genes provides another
engineering method. To
create a suitable
environment for themselves,
these Agrobacteria insert
their genes into plant hosts,
resulting in a proliferation of
modified plant cells near the
soil level.

16. CRISPR
Clustered regularly-interspaced short palindromic
repeats are segments of prokaryotic DNA containing
short repetitions of base sequences. CRISPR has
enormous potential application, including altering the
germline of humans, animals, and other organisms, and
manipulating the genes.

17. TALEN
Transcription activator-like effector nuclease has
TALE proteins that composed of a central domain
responsible for DNA binding, a nuclear localization signal,
and a domain that activates the target gene transcription.
The capability of this proteins to bind to DNA was first
described in 2007.

19. Transgenic
Plants have genes inserted into them that are
derived from another species. The inserted genes
can come from species within the same kingdom
(plant to plant).

20. Cisgenic
Plants are made using genes found within the
same species or closely related one, where
conventional plant breeding occur.

21. Subgenic
In 2014, Chinese researcher
Gao Caixia filed patents on
the creation of a strain of
wheat that is a resistant to
powdery mildew. The strain
lacks genes that encode
proteins that repress
defenses against mildew.
Gao used gene editing tools
without adding or changing
any other genes. No field
trials were immediately
planned.

22. Yields increased to 9% for herbicide tolerance and 25% for
insect resistance. Farmers who adopted GM crops made
69% higher profits than those who did not. The review found
that the GM crops help farmers in developing countries,
increasing yields by 14 percentage points.
GM crops grown today, or under development, have been
modified with various traits.
Traits
• improved shelf life
• disease resistance
• stress resistance
• herbicide resistance
• pest resistance
• Production of useful goods such as biofuel or drugs
• Ability to absorb toxins and for use in bioremediation of
pollution

23. Corn Tolerance of herbicides glyphosate
glufosinate, and 2, 4-D. Insect resistance.
Added enzyme, alpha amylase that
converts starch into sugar to facilitate
ethanol production. Viral resistance.
Genes, some
from BT, added
Rice Enriched with beta-carotene (a source of
vitamin A)
Genes from maize
and a common soil
microorganism
Soybeans Tolerance of glyphosate or glufosinate
Reduced saturated fats (high oleic acid); [145]
Kills susceptible insect pests
Viral resistance
Herbicide resistant
gene taken from
bacteria added
Knocked out native
genes that catlyze
saturation
Sugarcane Pesticide tolerance
High sucrose content
Genes added
GENETICALLY
MODIFIED CROPS

24. Pest Resistance
Insects
• Tobacco
• Corn
• Rice
Viruses
• Papaya -Papaya Ringspot Virus
• Potato -Potato Leaf Roll Virus
• Corn -Maize Dwarf Mosaic Virus

25. Plant species which are fed upon by an insect are called
host plants. The inability of insect to attack a non-host
plant is termed immunity. A host plant which shows lesser
damage is called resistant and a host plant showing more
damage is called susceptible.
Host plant resistance is any inherited
characteristic of a host that lessens the effect of attack.
Plant resistance to insects is ‘a quality that
enables a plant to avoid, tolerate or recover from the effect
of oviposition or feeding that would cause damage to other
genotypes of the same species under similar
environmental conditions’.

26. defined plant resistance as ‘the
relative amount of heritable qualities
possessed by the plant that influenced the
ultimate degree of damage done by the
insects’.
Resistance to insects is ‘the
inheritable property that enables a plant to
restrain the growth of insect populations or to
recover from injury caused by the populations’.
heritable, relative,
measurable, and variable’.

27. Underhill’ variety of wheat was found to be resistance
to Hessian fly, Mayetiola destructor
-‘Winter Majetin apples were reported resistance to the
woolly aphid, Eriosoma langigerum
-’Grapevine phylloxera, Viteus vitifoliae was controlled
in French vine yards by using resistant rootstocks of
America for grafting by Dr. C.V. Riley. This method was
named as ‘Riley method’.
Only after 1920, extensive studies were started on plant
resistance by the pioneer of resistance R.H. Painter (Kansas
State University, USA). He published a book “Insect
Resistance in Crop Plants” in 1951.

28. No heritable trait is involved
i. Host evasion: a host may pass through the most
susceptible stage quickly or at a time when number of insects
is less (early maturing varieties).
ii. Host escape: absence of infestation or injury to the
host plant because of transitory circumstances such as
incomplete infestation
iii. Induced resistance: increase in resistance
temporarily as a result of some changed conditions of plants
or environment such as change in the amount of water or
nutrient status of the soil or plant (low N, hing K, etc.)

29. A. Based on number of genes
i. Monogenic resistance- resistance is controlled by a
single gene
ii. Oligogenic resistance- resistance is controlled by
few genes
iii. Polygenic resistance- resistance is controlled by
many genes (also called as horizontal resistance)
B. Based on biotype reaction
i. Vertical resistance- resistance is specific to a given
biotype (less stable)
ii. Horizontal resistance- resistant against all the
known biotypes of insect also called ‘non-specific resistance’

30. C. Miscellaneous categories
i. Cross resistance- when a variety with
resistance to a particular pest may confer
resistance to another pest.
ii. Multiple resistance- ability of a variety to
resist variety of environmental stresses like
insect, diseases, nematodes, etc.

31. grouped mechanisms of resistance into
three main categories viz, non-preference, antibiosis and
tolerance
1. Non-preference or Antixenosis
The term antixenosis was coined by Kogan and
Ortman (1978). Xenosis means ‘guests’ in Greek. Antixenosis
refers to the ‘the resistance mechanisms employed by host
plant to deter or reduce colonization of insects’. Antixenosis
may result from certain morphological characteristics or the
presence of allelochemicals in the host plant, which adversely
affect the oviposition, rate of development, death, and
reproduction.

32. 2. Antibiosis
It refers to ‘the adverse effect of the host plant on the
biology (survival, development and reproduction) of the
insects and their progeny infesting it’. The adverse effect may
be due to presence of toxic substances, absence of
insufficient amount of essential nutrients, presence of
antimetabolites and enzymes, which adversely affect food
digestion, and utilization of nutrients.
The symptoms on insects affected by antibiosis are
death of immature stages, reduce growth rate, disruption in
conversion of ingested food, decline in size and weight of
larvae, prolongation of larval period, failure to pupate, death
in pupal stage, abnormal adults, reduced fecundity,
restlessness and abnormal behaviour.

33. 3. Tolerance
It refers to ‘the ability of the host plant to
withstand an insect population sufficient to
damage severely the susceptible plants’. It is
generally attributed to plant vigour, regrowth of
damage tissues, resistance to lodging, ability to
produce additional branches and compensation by
neighboring plants.

34. Bases of Resistance
1. Biophysical bases
The morphological and anatomical characteristics of a
plant like colour, shape, size, thick cuticle, trichomes, surface
waxes, silica deposits, glandular hairs, tight leaf sheath,
compact panicle and tightness of husk influence insects’
preference. The resistance mechanisms related to
morphological or structural plant features all together is called
‘phenetic resistance’. Phenetic resistance causes reduced or
impaired feeding or oviposition and contribute to the action of
other mortality factors.

35. 1. Tightly wrapped leaf sheath, closely packed
vascular bundles and high silica content –Rice
stem borer
2. Red pericarp and surface wax –Brown plant
hopper
3. Pubescent varieties of soybean, cotton, and
bhendi –Leaf hopper
4. Frego bract cotton varieties –Boll weevil

36. 2. Biochemical bases
Several inorganic chemicals in plants impart
resistance to a wide variety of insect pests.
Examples:
1. Nutrients: Asparagine in Mudgo rice variety –
Brown plant hopper
Low carbohydrates –Mexican bean beetle, Epilachna
varivestis
Low amino acids –Pea aphid, Acyrthrosiphon pisum
2. Allelochemicals: DIMBOA (2,4-dihydroxil -7 methyl 1-1,4
benozoxaxine-3-one) –European corn borer, Ostrinia
nubialis
Cucurbitacins –Many cucurbit pests especially
Epilachna sp.
Gossypol in cotton –Helicoverpa zea
Pentadecanal in TKM 6 rice –Stem borer

37. Host Plant Resistance in Pest Management
Until 1960, the host plant resistance as a
method of insect control received little attention
except in few cases. However, the growing
awareness of the limitations of pesticides in recent
years has caused an upsurge of interest in this
approach in insect control through developing a
resistant variety involves faculties of different
department ad requires several years.

38. Methods of developing resistant varieties
1. Screening of available germplasm sown in lines
under natural field conditions
2. Selective screening of elite entries under natural
infestation through replicated trials
3. Selective screening of elite entries under
bombarded condition in cages.

39. Resistant varieties
Crop Pest Resistant varieties
Rice Stem borer TKM 6, IR 20,
Paiyur 1
BPH CO 42, P 43,
Ptb 33, IR 36, IR 64
GLH CR 1009, IR
20, IR 50, TKM 6
Gall Midge MDU3, Shakti,
Vikram
Sugarcane ESB CO 312, 421, 661,
917, 853
Internode borer CO 975, CO 7304
Top shoot borer CO 745, CO 6515
Mealy bug CO 439, CO 443,
CO 720, CO 730

40. Corn Bollworm Abhadita
Stem weevil MCU 3, Supriya
White fly Kanchana, LPS
141
Leaf hopper MCU 5,
SRT 1,
Gujarat 67,
K7, K8
Sorghum Earhead bug K tall
Jasmine Eriophyid mite Pari mullai

41. Integration with other tactics
1. Chemical control: High mortality of plant and
leafhoppers was observed on resistant than on
susceptible rice varieties when sprayed with
insecticides. In many cases, the plant resistance
enhances the efficacy of insecticides. Also it
reduces the amount of insecticides required. For
example, the amount of malathion required to kill
aphid Myzus persicae, on Brussel’s sprouts is
reduced by 45% on partially resistant varieties.

42. 2. Biological control: Though compatible,
indirectly affect the natural enemies by reducing
pest numbers. But it weakens the pest populations,
which will make the pests more susceptible to
natural enemies. For example, the predatory
potential of spider Lycosa pseoannulata on BPH is
increased on resistant varieties.

43. 3. Cultural control: Cultural practices (N and K
management) cause specific physiological
changes that reduce the suitability of host plants
for phytophagous insects for example.

44. Advantages of Host Plant Resistant
• Selective – against a particular pest thus no
adverse effects on other insects or non-target
organisms.
• Cumulative – effect continuous against
successive generations
• Persistence – durable for long period
• Ecofriendly – no pollution or deleterious
effects
• Easily adaptable – at does not require
additional cost and easy to adopt by farmers

45. • Effective under all conditions
• Compatible – compatible with other pest
control practices. Activity of insecticides and
natural enemies is more on resistant varieties
• Reduces pesticide application – lessens
frequent pesticide applications
• Useful for low value crop

46. Disadvantages of Host Plant
Resistance
• Time consuming
• High initial cost
• Biotype selection
Biotypes are discrete populations capable of utilizing and
damaging the plant genotypes resistant to other
populations of the same species. The biotypes are
developed due to the selection pressure when resistant
cultivars are grown widely. These biotypes can be
overcome by polygenic resistance.

47. • Conflicting resistance factors
Some plant traits confer resistance to one pest but
enhance susceptibility to others. E.g. pubescent
cotton varieties resistant to leafhopper are
susceptible to bollworms. Frego bract in cotton
mediates resistance to American boll weevil but
magnifies susceptibility to plant bugs.