Drought, salinity, high temperature, and low temperature all have a significant impact on plant growth and productivity, resulting in yield losses. Because of climate change and environmental degradation, these stresses have become a major challenge for global food security. Traditional breeding methods have had limited success in producing plants with improved stress tolerance. Transgenic approaches, on the other hand, have provided an alternative and effective means of improving plant tolerance to abiotic stresses. Transgenic plants are created by genetically modifying plants by inserting foreign genes into the plant genome. Specific traits encoded by the introduced genes can improve plant growth and tolerance to abiotic stresses. These genes can come from other plant species as well as non-plant organisms. Several genes that play critical roles in increasing plant tolerance to abiotic stresses have been identified and characterized. Overexpression of genes encoding osmoprotectants like proline and glycine betaine, for example, has been shown to improve plant tolerance to drought and salinity and overexpression of genes encoding antioxidant enzymes such as superoxide dismutase and catalase improves plant tolerance to oxidative stress. Another strategy involves manipulating signaling pathways that control plant responses to abiotic stresses. for example, Overexpression of genes encoding transcription factors such as DREB and Cnb-1 has been shown to improve plant tolerance to drought, salinity, and cold stress. These transcription factors control the expression of genes involved in stress tolerance, such as those encoding for osmoprotectants and antioxidants. The use of transgenic approaches has shown great potential for improving plant tolerance to abiotic stresses. For example, the development of drought-tolerant rice has been achieved through the overexpression of genes OsNAC9 for root development. A1b regulates the HSP in wheat which helps in heat stress tolerance. In conclusion, abiotic stress tolerance is an important trait for plant growth and productivity, particularly in the face of climate change and environmental degradation. Transgenic approaches have proven to be an efficient way of increasing plant tolerance to abiotic stresses. These methods entail inserting foreign genes into plant genomes, which can improve plant growth and stress tolerance. While there are some reservations about using transgenic plants, the benefits of improved stress tolerance for agriculture and food security cannot be overlooked. To ensure safe and sustainable agricultural practices, it is critical to continue developing and deploying transgenic plants with effective biosafety protocols.

1. Department of Plant Physiology
SKN College of Agriculture, Jobner
Seminar on: Molecular Response and
Approaches of Plants to Abiotic Stresses
Submitted by,
Pritish Priyadarshi Swain
M. Sc. Ag (Plant Physiology)
Guided by,
Dr. Sunita Gupta,
Professor & Head
Dept. of Plant Physiology
Sri Karan Narendra Agriculture University, Jobner

2. Department of Plant Physiology
SKN College of Agriculture, Jobner
Seminar on: Molecular Response and
Approaches of Plants to Abiotic Stresses
Submitted by,
Pritish Priyadarshi Swain
M. Sc. Ag (Plant Physiology)
Guided by,
Dr. Sunita Gupta,
Professor & Head
Dept. of Plant Physiology
Sri Karan Narendra Agriculture University, Jobner

3. Department of Plant Physiology
SKN College of Agriculture, Jobner
Seminar on: Transgenic Approaches For Abiotic Stress
Tolerance In Plants
Submitted by,
Pritish Priyadarshi Swain
M. Sc. Ag (Plant Physiology)
Guided by,
Dr. Sunita Gupta,
Professor & Head
Dept. of Plant Physiology
Sri Karan Narendra Agriculture University, Jobner

4. Content
Introduction
Stress and it’s types
Effect of Abiotic stress
Approaches for stress tolerance
Conclusion

5. Introduction
• The Stress is any change in environmental conditions that
can reduce or adversely change a plants growth and
development. (Jacob Levitt,1980)
Losses due to stress
• The progressive salinization of soil, estimated at around
20 % of irrigated land in world (Ghassemi et al.,1995)
• High temperature coupled with drought during
pollination period of maize plants can result in up to 100
% yield loss (Heiniger et al., 2001)
• Globally, abiotic stress is the key sources of crop loss,
reducing more than 50% average yields for most major
crop plants(Acquaah, 2007)
• The estimated potential yield losses are 17 % due to
drought, 20 % due to salinity, 40 % due to high
temperature, 15 % due to low temperature and 8 % due
to other stress (Ashraf et al., 2008)

6. Types of stress
Stress
Abiotic
Physical Chemical
Biotic

7. Physical
Stress
Temperature
•High
•Low
Water
•Deficit
•Excess
Radiation
Mechanical
Electrical
Magnetic
Chemical
Nutrients
•Toxic
•Deficiency
Salts
•Toxic
•Deficiency
Air Pollution
Allelochemicals
Pesticides
Toxins
Biotics
Insects
Diseases
Allelopathy
Human
activities

8. Physical
Stress
Temperature
•High
•Low
Water
•Deficit
•Excess
Radiation
Mechanical
Electrical
Magnetic
Chemical
Nutrients
•Toxic
•Deficiency
Salts
•Toxic
•Deficiency
Air Pollution
Allelochemicals
Pesticides
Toxins
Biotics
Insects
Diseases
Allelopathy
Human
activities

9. Physical
Stress
Temperature
•High
•Low
Water
•Deficit
•Excess
Radiation
Mechanical
Electrical
Magnetic
Chemical
Nutrients
•Toxic
•Deficiency
Salts
•Toxic
•Deficiency
Air Pollution
Allelochemicals
Pesticides
Toxins
Biotics
Insects
Diseases
Allelopathy
Human
activities

10. Characteristics of abiotic stresses
Effects generated by one abiotic stress may overlap with some effects of another stress.
Differential response of plant species to a given stress.
One stress may increase or decrease the level of another stress.
Some stresses are impossible to manage.
Unpredictable occurrence.

11. Drought
Stress
Drought is an extended abnormal dry period
that occurs in a region consistently receiving a
below-average rainfall.
Globally, agriculture is the biggest consumer of
water, accounting for almost 70% of all
withdrawals, and up to 95% in developing
countries. (FAO,2017)
The severity of drought is unpredictable as it
depends on many factors such as occurrence
and distribution of rainfall, evaporative
demands and moisture storing capacity of soils

12. TYPES OF DROUGHT
Meteorological
Drought- rainfall <
25 % of the
average of the
region (<50 %-
severe drought
Agricultural
Drought- lack of
rainfall result in
insufficient
moisture in the
root zone.
Hydrological
Drought- extended
dry period leading
to marked
depletion of
surface water
leading to drying up
of reservoir, lacks
,streams and rivers
etc.

13. EFFECT OF DROUGHT STRESS
Effect on Growth: Reduction in Turgor Pressure, due to cell sizes will be smaller.
Effect on Photosynthesis: Photosynthesis decreases, stomatal closure, decrease in
electron transport.
Decrease in nuclear acids and proteins: Protease activity↑, free Amino acid↑,
RNAase activity↑，RNA hydrolysis, DNA content falls down.
Effect on Nitrogen Metabolism: Nitrate reductase activity↓
Effect on Carbohydrate metabolism: Loss of starch and increase in simple sugars,
carbohydrate translocation decreases.

14. Temperature
Stress
High
temperature
Low
temperature
Chilling freezing

15. High Temperature Stress
Heat injury is a damage to the
temperature- mediate plant by
high temperature above 45℃.
Heat stress is defined as the rise
in temperature beyond a
threshold level for a period of
time sufficient to cause
irreversible damage to plant
growth and development.
(Hall,2001)

16. Effect of Heat Stress
Physiological changes
Phenological changes
Anatomical changes
Morphological symptoms

17. Physiological changes
Physiological
change
Photosynthesis
Reproduction
Phenology
Mineral
nutrition
Growth

18. Phenological changes
• The crop duration was reduced under elevated temperature in rice
Temperature Duration
Ambient +4 °C 96
Ambient +2 °C 102
Ambient 108
(Rani,2013)

19. Anatomical
changes
• Reduction in cell size
• Closure of stomata
• Increased stomatal and
trachomatous density
• Greater ylem vessels
• Damaged mesophyll cell and
increased permeability of plasma
membrane

20. Morphological Symptoms
• Scorching of leaves and twigs
• Sunburn on leaf branches and stems
• Shoot and root growth inhibition
• Fruit discolouration and damage
• Reduction in internode length
• Disruption in reproduction due to damaged Anther and lowered
Fertilization

21. Low temperature stress
Chilling Stress
• Damaging effect of low
temperature above freezing point
• 0-15° C
• Tropical and Sub tropical crop are
affected
Freezing stress
• Damage due to freezing of
intercellular water content into ice
crystals
• < 0° c
• Temperate region

22. Salinity Stress
Salinity stress is an environmental
stress that occurs when the soil or
water surrounding a plant contains
high levels of salt i.e, Na+ , K+ ,Ca 2+.
High salinity levels can interfere
with a plant's ability to take up
water and nutrients, which can lead
to reduced growth, yield, and
quality.

23. Effects on plant growth and development
Oxidative stress
Ion toxicity
Reduced growth
Altered gene expression
Increased susceptibility to other stresses
Changes in plant physiology

24. Stress resistance
mechanisms
• Avoidance
prevents exposure to stress
• Tolerance
permit the plant to withstand
stress
• Acclimation
alter their physiology in response
to stress

25. Source: Cell & Cellular Life Sciences Journal , Pande A and Arora S

26. Conventional Breeding
Conventional breeding (classical
breeding or traditional
breeding), is the development
of new varieties (cultivars) of
plants by using older tools and
natural processes.
It generally involves
Domestication, Introduction,
Selection, Hybridization

27. Molecular
breeding
Marker-assisted selection is an indirect selection process where a
trait of interest is selected based on a marker
Marker-assisted Backcrossing in which the goal is to incorporate a
major gene from an agronomically inferior source (the donor parent)
into an elite cultivar or breeding line (the recurrent parent).
Marker-assisted Gene Pyramiding :Gene pyramiding, which aims to
assemble multiple desirable genes into a single genotype. Marker-
based gene pyramiding is now the method of choice for inbred line
development targeted at improving traits controlled by major genes.
Marker-assisted Recurrent Selection : The objective of marker
assisted recurrent selection (MARS) is to increase the frequency of
favorable marker alleles in a population before inbred line
extraction.

28. Transgenic Approach to Improve Stress
Tolerance
Stress-induced gene expression can be broadly categorized
into three groups:
(1) genes encoding proteins with known enzymatic or structural functions,
(2) proteins with as yet unknown functions, and
(3) regulatory proteins.
Initial attempts to develop transgenics (mainly tobacco) for abiotic stress tolerance
involved ‘‘single action genes’’ i.e., genes responsible for modification of a single
metabolite that would confer increased tolerance to salt or drought stress

29. Single Action
Genes
Osmoprotectants:
• These fall into two categories: sugars and sugar alcohols,
and zwitter ion compounds. Sugars include sugar alcohols
such as mannitol, sorbitol, pinitol and oligosaccharides
such as trehalose and fructans. The latter class includes
amino acids such as proline, and quaternary ammonium
compounds such as glycine betaine.
• Basic strategy for engineering resistance to water deficit
stress have therefore focused on production of
osmoprotectants as a mechanism for overcoming the
osmotic stress generated by water deficit.
• This requires the determination of the biosynthetic
pathways for various osmoprotectants, isolation of
relevant genes, and appropriate engineering of constructs
to target gene expression and protein destination.

30. Osmoproctant Transgene Crop plant Stress
tolerance
Glycine betaine E. coli bet A Tobacco Drought, salt
Polyamines Arginine
decarboxylase
Rice Drought
Proline Moth bean P5CS Tobacco Salt
Mannitol E. coli mt1D Arabidopsis Salt
Sorbitol Apple s6pdh Tobacco Oxidative stress
Trehalose Yeast tps1 Tobacco Drought
Fructans Bacillus subtilis
sacB
Sugar beet Drought

31. • Osmoproctentants have two
roles: protection of vulnerable
molecules and osmotic
adjustment. Drought toleramce
by expressing these molecules can
improve plant survival but may
not increase yields to viable levels

32. Accumulation of these molecules helps plants to
Retain water within cells and protects cellular compartments from injury caused by
dehydration
Maintains turgor pressure during water stress
Stabilize the structure and function of certain macromolecules
Signaling functions or induction of adaptive pathways
Scavenge reactive oxygen species

33. Proline
Proline accumulates in many organisms in
response to drought and salinity
Proline is encoded by a nuclear gene
Pyrroline-5 carboxylate synthetase {PSCS)
Proline may serve as a hydroxyl radical
scavenger reducing the acidity of the cell
It may also function as an osmolyte and
molecular chaperone
C5H9NO2

34. Glycine Betaine

35. Glycine Betaine
• GB accumulates in the chloroplasts and plastids and increases the tolerance of plants to various
abiotic stresses (drought, salinity and freezing)
• The physiological role of GB in alleviating osmotic stress
• It can also protects proteins and enzyme activities under water deficits and stabilize membranes
during freezing
• It can help stabilize the protein tertiary structure and prevent or reverse disruption of the tertiary
structure
• Accumulation of GB is limited due to choline supply
• Transgenic potato plants expressing a bacterial choline oxidase (betA) gene leads to high levels of
GB under drought stress

36. Sugars and Sugar Alcohols
• Accumulation of sugar-related compounds, response to osmotic stress
• These compounds sta bilize the membranes and proteins during dehydration
• Sugars can replace the water molecules and stabilize the proteins or membranes in a
similar of water molecules
• They can form a glass phase in the dry state of high viscosity have capable of slowing down
chemical reactions lead to long-term stability in a living system

37. Trehalose
Trehalose, a rare non-reducing sugar
Trehalose protects the biological molecules in response to different stress conditions
It does not accumulate to high enough levels in most plants, probably because of the presence of
trehalase activity
Trehalose synthesized in two steps from glucose-6-phosphate and uridine diphosphoglucose, via
trehalose-6-phosphate
The first step is catalyzed by trehalose phosphate synthase (TPS), and the second by trehalose-6-
phosphatase (TPP)

38. Osmolyte and Compatible Solutes
Gene Protein Source Cellular role(s)
gpat Glycerol 3-
phosphate
acyltransferase
Cucurbita
maxima,
Arabidopsis
thaliana
Fatty acid
unsaturation
mtlD Mannitol 1-
phosphate
dehydrogenase
Eschericia coli Manitol
biosynthesis
sod Superoxide
dismutase
Nicotiana
plumbaginifolia
Superoxide
dismutase
Bet-B Betaine aldehyde
dehydrogenase
Eschericia coli Glycinebetaine
dismutase

39. Gene Protein Source Cellular role(s)
Bet-A Choline
dehydrogenase
Eschericia coli Glycinebetaine
dismutase
p5cs Pyroline 5-
carboxylase
synthase
V. aconitifolia Proline
biosynthesis
Sac-B Levan sucrase Baccilus subtilis Fructan
biosynthesis
Hva-1 LEA protein Hordeum vulgare -
Tps-1 Trehalose 6-
phosphate
synthase
Arabidopsis
thaliana
Trehalose
biosynthesis

40. Gene Protein Source Cellular role(s)
Cod-A/Cod-
1/Cox
Choline oxidase Arthrobacter
globiformis
Glycinebetaine
biosynthesis
afp Antifreeze
protein (AFP)
Synthetic Inhibit ice growth
and
recrystallization
Imt-1 Myo-inositol-o-
methyl
transferase
Messembryanthe
mum
crystallinum
D-ononitol
biosynthesis
BADH Betaine
dehydrogenase
Spinach Glycinebetaine
byosynthesis

41. Gene Protein Source Cellular role(s)
Ect-A, Ect-B, Ect-C L-2,4-diaminobutyric
acetyltransferase
L-2,4-diaminobutyric
acid trans-aminase
L-ectoine synthase
Halomonas
elongata
Ectoyne
Ots-A, Ots-B Trehalose-6-P
synthase
Trehalose-6-P
phosphatase
Eschericia coli Trehalose
Pro-DH Proline
dehydrogenase
Arabidopsis
thaliana
Proline
HAL-3 FMN-binding protein Saccharomyces
cerevisae
Na+/K+
homeostasis

42. Detoxifying genes
• In most of the aerobic organisms, there is a need to effectively
eliminate reactive oxygen species (ROS) generated as a result of
environmental stresses.
• In order to control the level of ROS and protect the cells from
oxidative injury, plants have developed a complex antioxidant defense
system to scavenge the ROS.
• These antioxidant systems include various enzymes and non-
enzymatic metabolites that may also play a significant role in ROS
signaling in plants.
• For example transgenic tobacco coding for superoxide dismutase in
cytosol, mitochondria, chloroplast have been generated
• Ascobate peroxidase , glutathione reductase and glutathione
peroxidase have been transformed into Arabidopsis and tobacco
plants and shown to have some impact on various abiotic stresses
such as heat, cold and salinity.

43. Reactive oxygen species (ROS)

44. Redox Proteins
Gene Protein Source Cellular role(s)
MnSOD Superoxide dismutase Saccharomyces
cerevisiae
Reduction of O2
content
Gly-1 Glyoxylase Brassica juncea S-D-
lactoylglutathione
TPX-2 Peroxidase Nicotiana tabacum Change cell
properties
GST
GPX
Glutathione S-transferase
Glutathione peroxidase
Nicotiana tabacum
Nicotiana tabacum
ROS scavenging

45. Late embryogenesis abundant (LEA) proteins
• Another category of high molecular weight proteins that
are abundant during late embryogenesis and accumulate
during seed desiccation and in response to water stress
• Constitutive overexpression of the HVA1, a group 3 LEA
protein from barley conferred tolerance to soil water
deficit and salt stress in transgenic rice plants
• The group 1 LEA proteins are predicted to have enhanced
water-binding capacity, while the group 5 LEA proteins
are thought to sequester ions during water loss.
• Also play a role in anti aggregation of enzymes under
dessication and freezing stresses.

46. Important strategy for achieving greater tolerance to abiotic stress is to
help plants to re-establish homeostasis under stressful environments,
restoring both ionic and osmotic homeostasis.
A number of abiotic stress tolerant transgenic plants have been
produced by increasing the cellular levels of proteins (such as
vacuolar antiporter proteins) that control the transport functions.
For example, transgenic melon and tomato plants expressing the
HAL1 gene showed a certain level of salt tolerance as a result of
retaining more K+ than the control plants under salinity stress.
Transporter Genes

47. Transgenic approaches also aim to improve photosynthesis under abiotic stress conditions through changes
in the lipid biochemistry of the membranes.
Adaptation of living cells to chilling temperatures is a function of alteration in the membrane lipid
composition by increased fatty acid unsaturation.
Genetically engineered tobacco plants over-expressing chloroplast glycerol-3-phosphate acyltransferase
(GPAT) gene (involved in phosphatidyl glycerol fatty acid desaturation) from squash (Cucurbita maxima) and
A. thaliana showed an increase in the number of unsaturated fatty acids and a corresponding decrease in the
chilling sensitivity.
Multifunctional genes for lipid biosynthesis

48. Regulatory genes
• Many genes that respond to multiple stresses like
dehydration and low temperature at the transcriptional
level are also induced by ABA, which protects the cell
from dehydration
• In order to restore the cellular function and make
plants more tolerant to stress, transferring a single
gene encoding a single specific stress protein may not
be sufficient to reach the required tolerance levels
• To overcome such constraints, enhancing tolerance
towards multiple stresses by a gene encoding a stress
inducible transcription factor that regulates a number
of other genes is a promising approach
• The CBF1 cDNA when introduced into tomato
(Lycopersicon esculentum) under the control of
aCaMV35S promoter improved tolerance to chilling,
drought and salt stress but exhibited dwarf phenotype
and reduction in fruit set and seed number

49. Genes involved in stress signal sensing and a cascade of stress-signaling in A.
thaliana has been of recent research interest.
Abiotic stress signaling in plants involves receptor-coupled phospho-relay,
phosphoionositol- induced Ca2+ changes, mitogen activated protein kinase
(MAPK) cascade, and transcriptional activation of stress responsive genes
One of the merits for the manipulation of signaling factors is that they can
control a broad range of downstream events that can result in superior
tolerance for multiple aspects
Alteration of these signal transduction components is an approach to
reduce the sensitivity of cells to stress conditions, or such that a low level of
constitutive expression of stress genes is induced.
Overexpression of functionally conserved At-DBF2 (homolog of yeast DBf2
kinase) showed striking multiple stress tolerance in Arabidopsis plants
Signal
transduction
genes

50. Transcription and signal transduction factors
Gene Protein Source Cellular role(s)
DREB-1A Transcription factor Arabidopsis
thaliana
Improved gene
expression
Cnb-1 Calcineurin Saccharomyce
s cerevisiae
Improved Ca++
signaling
OsCDPK-7 Protein kinase Oryza sativa Improved gene
expression

51. The heat shock response, the increased transcription of a set of genes
in response to heat or other toxic agent exposure is a highly conserved
biological response, occurring in all organism.
The response is mediated by heat shock transcription factor (HSF)
which is present in a monomeric, non-DNA binding form in unstressed
cells and is activated by stress to a trimeric form which can bind to
promoters of heat shock genes.
The induction of genes encoding heat shock proteins (Hsps) is one of
the most prominent responses observed at the molecular level of
organisms exposed to high temperature
Genetic engineering for increased thermo-tolerance by enhancing
heat shock protein synthesis in plants has been achieved in a number
of plant species
Heat shock
protein
genes

52. During the period of acclimation, plants produce a
number of cold induced proteins that are assumed
to play a role in the subsequent cold resistance.
These are encoded by class of genes designated as
cold-responsive (COR) genes according to their
patterns of expression.
Overexpression of ectopic expression of these cold
induced proteins could therefore be a possible
route to the specific engineering of cold or freezing
stress tolerance
Cold
induced
proteins

53. Gene Protein Source Cellular
role(s)
DnaK Heat shock protein A. halophytica Protein
stabilization
Apo-Inv Apoplastic yeast-
derived invertase
Saccharomyc
es cerevisiae
Sucrose
synthesis

54. Genetic Engineering of Cell Membranes
Membranes are critical sites of injury by chilling, freezing, heat and osmotic
stresses
Increased levels of unsaturated membrane lipids leads to higher membrane
fluidity which improves plant-chilling tolerance and photosynthetic parameters
Example:Tobacco transformed with acyl-ACP:glycerol-3-phosphate
acyltransferase (GPAT) from chilling- tolerant species of Arabidopsis acquired
chilling tolerance

55. Novel
approaches
• Utilization of CRISPR (clustered regularly
interspaced short palindromic repeats)
• The CRISPR/Cas realizes the
recognition process through the base
complementation between guide RNA
and target sequence, which is simple and
flexible, and the target site selection only
needs to conform to the requirements of
protospacer-adjacent motif (PAM) of
different systems.
• Enhancing abiotic stress resistance
(Bouzroud et al., 2020)

56. Case Studies-1
Crop : Rice
Experimental Site : Rural Development Administration, Suwon
(127:01E/37:16N), Korea (2009), and subsequently at the
Kyungpook National University, Gunwi (128:34E/36:15N), Korea
(2010)

57. Result and finding
The overexpression of OsNAC9 alters the root architecture of rice plants enhancing drought resistance and grain
yield under field conditions
Redillas et, al., Plant Biotechnology Journal(2010)

58. The overexpression of OsNAC9 alters the root architecture of rice plants enhancing drought resistance and grain
yield under field conditions
Redillas et, al., Plant Biotechnology Journal(2010)

59. Case Study-2
Crop : Tomato
Experimental Site : Boyce Thomson Institute, Cornell University, NY,
USA

60. Results and finding
Fig: Complementation of Arabidopsis sos2‐2 mutant by SlSOS2. Six‐day‐old seedlings of
wild‐type Col‐0 and sos2‐2 mutant expressing or not SlSOS2 were transferred from
Murashige and Skoog (MS) medium to MS medium supplemented with 0 and 75 mm
NaCl and imaged after 7 d of treatment (a). Seedling root length (b) and fresh weight (c)
are shown as means ± standard deviation (n = 10). FW, fresh weight.
Raul et, al., Plant, cell & environment(2012)

61. Fig: Effect of SlSOS2 overexpression on growth of tomato plants under salt treatments. (a) Four‐day‐old T2
transgenic (L7‐4 and L8‐2) and untransformed (C) seedlings cultivated on Petri dishes in Murashige and Skoog
(MS) medium were transferred to Petri dishes containing the same medium supplemented with 0, 80, 120 and 150
mm NaCl and grown on it for five additional days. Upper panel shows an image of a representative experiment
after 5 d cultivation with 0 and 120 mm NaCl. Lower panel shows the growth rate of primary root, in cm day−1,
of transgenic and non‐transformed seedlings after 5 d treatment with 120 mm NaCl. (b) Twenty‐five‐day‐old T2
transgenic (lines L7‐4 and L8‐2) and untransformed (C) tomato plants were treated with 0 and 120 mm NaCl in
hydroponic cultivation conditions. Upper panel shows an image of a representative experiment after 10 d of salt
treatment. Lower panel shows the relative growth rates (RGRs),
Raul et, al., Plant, cell & environment(2012)

62. Case Study -3
Crop : wheat and Arabidopsis
Experimental Site : Boyce Thomson Institute, Cornell University, NY,
USA

63. Results and Findings
Fig:OPR3 contributes to heat tolerance in wheat and Arabidopsis
(a) Expression analysis of TaOPR3 in KN199 (CK), TaOPR3 RNAi
and overexpression transgenic lines. (b) Phenotypic analysis
of KN199, TaOPR3 RNAi and overexpression transgenic lines in
response to heat stress.
Tian et, al., Plant, cell & environment(2020)

64. Fig:Statistical analysis of fresh weight (c) and electronic leakage (d) for CK, Ri
and OE seedlings after heat stress. (e) Statistical analysis of electronic leakage of CK, Ri
and OE seedlings with or without MeJA treatment after heat stress.
Tian et, al., Plant, cell & environment(2020)

65. Limitations
• Health related issues, such as allergens. Toxins,
Antibiotic resistance
• Terminator technology
• Environ mental and ecological issues, such as, Potential
gene escape and super weeds, Pesticide resistance,
Loss of biodiversity

66. Conclusion
• Genetic engineering has the potential to enhance
abiotic stress tolerance in crops and improve yields
under adverse environmental conditions.
• By identifying stress-responsive genes and introducing
them into crops, researchers have successfully
developed transgenic plants with improved tolerance
to drought, salt, cold, and heat stress.
• However, there are still concerns regarding the
potential impact of genetically modified crops on the
environment and human health.
• For which extensive research is needed
• But still other agricultural practices should be
promoted

67. Referance
• Tian, X., Wang, F., Zhao, Y., Lan, T., Yu, K., Zhang, L., Qin, Z., Hu, Z., Yao, Y., Ni, Z., Sun, Q., Rossi,
V., Peng, H., & Xin, M. (2020). Heat shock transcription factor A1b regulates heat tolerance in wheat
and Arabidopsis through OPR3 and jasmonate signalling pathway. Plant biotechnology journal, 18(5),
1109–1111. https://doi.org/10.1111/pbi.13268
• Huertas, R., Olias, R., Eljakaoui, Z., Gálvez, F. J., Li, J. U. N., De Morales, P. A., ... &
RODRÍGUEZ‐ROSALES, M. P. (2012). Overexpression of SlSOS2 (SlCIPK24) confers salt tolerance to
transgenic tomato. Plant, cell & environment, 35(8), 1467-1482.
• Redillas, M. C., Jeong, J. S., Kim, Y. S., Jung, H., Bang, S. W., Choi, Y. D., ... & Kim, J. K. (2012). The
overexpression of OsNAC9 alters the root architecture of rice plants enhancing drought resistance and
grain yield under field conditions. Plant Biotechnology Journal, 10(7), 792-805.
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• Levitt, J. (1980). Responses of Plants to Environmental Stress, Volume 1: Chilling, Freezing, and High
Temperature Stresses. Academic Press..
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causes, extent, management and case studies. CAB international.
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University. http://www.ces.ncsu.edu/plymouth/cropsci/docs/early_drought_impact_on_corn.html.
• Acquaah, G (2007). Principles of plant genetics and breeding. Oxford: Blackwell, pp. 385
• Ashraf, M., Athar, H. R., Harris, P. J. C., & Kwon, T. R. (2008). Some prospective strategies for
improving crop salt tolerance. Advances in agronomy, 97, 45-110.
• Pande, A., & Arora, S. (2017). Molecular strategies for development of abiotic stress tolerance in plants.
Cell & Cellular Life Sciences Journal, 2(2), 000112.
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