Phenotypic plasticity refers to the ability of a single genotype to produce different phenotypes in response to environmental conditions. It allows organisms to adapt to varying environments through changes in physiology, biochemistry, morphology and performance. Plasticity can occur at both the individual level through behavior and physiology, and at the population level through performance and trait expression. The degree of plasticity is represented by reaction norms that show the range of phenotypes a genotype can produce across environments. Plasticity evolves when stress periods are shorter than an organism's lifespan and there are reliable cues to indicate stress. It allows for reversible changes that maximize fitness in variable conditions. Studies of plasticity in crops have shown changes in traits like root structure, leaf pigmentation

1. Phenotypic Plasticity in Crop Plants
1
D. SUNEEL
BAM-17-22

2. 2
Phenotypic Plasticity:
The extent of phenotypic change in
response to a signal is called phenotypic
plasticity.
or
The modification of developmental events
by the environment.
or
The ability of one genotype to produce
more than one phenotype when exposed
to different environments. (Schlichting,1986)

3. 3
How do organisms respond to
environmental change?
At the individual level:
Behavior
Physiology
Plasticity
At the population level:
Behavior
Performance
Physiology, Biochemical and
Morphological
Plasticity

5. 5
The ability of one genotype to produce
more than one phenotype when exposed
to different environments.
Environment
Trait
Environment
Trait
Environment
Trait
No Plasticity Plasticity
Highly Variable
Plasticity, strong
Genotype-by-
Environment
Interaction
Each of the colored lines is a "Reaction Norm"

6. 6
DNA
Proteins, etc.
Organelles
Cells
Tissues
Organs
Organ
Systems
Organismal
Performance
Behavior
Hierarchical masking effects:
Compensatory
plasticity at
lower levels
could lead to
reduced
plasticity at
higher levels

7. 7
Features of "Phenotypic Plasticity"
The changes may or may not be reversible.
The changes may or may not be adaptive in the
sense of increasinzg the organism's reproductive
success (Darwinian fitness).

8. 8
1. Something in the internal and/or external
environment changes (usually)
2. Organism senses that change
3. Organism alters gene expression
4. Usually, the altered gene expression
yields additional observable phenotypes
Important Features of "Phenotypic Plasticity"
Includes "acclimation" and "acclimatization"
as well as learning and memory.

9. 9
When should plasticity evolve?
"Stress occurring in periods shorter than life span strongly selects
for reversible phenotypic plasticity, for maximum reliability of stress
indicating cues and for minimal response delays depending on
(1) length of stress periods,
(2) response delay for switching into the induced phenotype,
(3) response delay for rebuilding the non-induced phenotype,
(4) intensity of stress, i.e, mean value of the stress inducing environment,
(5) co-efficient of variation of the stress environment and
(6) completeness of information available to the stressed organism.
Adaptively reversible phenotypic plastic traits will most probably
affect fitness in a way that can be described by simultaneous reversible
plasticity in mode and breadth of tolerance functions”.
Gabriel, 2005.

10. viswanathan et al., (2009)

11. Gouldetal.,(2014)

12. Emery(2009)

13. Christine et al., 2012
Rice

14. Wheat

15. Source:

17. Root-type-specific plasticity in response to localized high nitrate supply in maize (Zea mays).
Annals of Botany. 2015. 116 (5): 751-762.

18. (a) Inbred replicates of the
same Polygonum
lapathifolium genotype
grown for eightweeks at
low light [20% available
photosynthetically active
radiation (PAR); left] and
high light (100% available
PAR; right).
Sonia e. Sultan(2000)
Legume

19. Phenotypic differences between
genetically uniform Polygonum
lapathifolium plants grown in dry (a)
and flooded (b) soil include dramatic
changes to the root system.
(a) nutrient-poor sand beaches of
freshwater ponds. (b) moderately
shaded, mesic habitats. (c) Compared
with less broadly distributed annual
Polygonum persicaria.
Sonia e. Sultan (2000)

20. Groundnut
Apurba Pal et al., 2017

21. Response of leaves to excess light, temperature, osmatic extremes via production of
anthocyanin to protect photosynthetic machinery.
Nicotra et al. (2010)

22. Nicotra et al., (2010)

23. Plasticty in plants induced by interactions with herbivores
Kailen et al., (2007)

24. Plasticity in herbivore induced by interactions with plants
Kailen et al., (2007)

25. Norms of reaction for specific leaf area in
10 P. persicaria genotypes
Norms of reaction for root to shoot
biomass ratio in eight P. persicaria
genotypes cloned and grown at four soil
moisture levels.
S. E. Sultan (1995)

26. Five possible evolutionary responses to the environment:
Kattia et al., (2015)

27. Plasticity for total lifetime reproductive output (total achene biomass) in
four Polygonum species, showing complex environmental effects.
Sonia e. Sultan (2003)

28. Plasticity for mass of individual offspring
(achenes) in four Polygonum species, showing
contrasting patterns of change
Sonia e. Sultan (2003)

29. conclusion
1. A particular environmental stress may initiate a suite of
plastic changes involving several salient aspects of
development.
2. plasticity expressed early in ontogeny may constrain
developmental plasticity for other aspects of the phenotype
later in life.
3. New cultivars can then be tailored to expected future
conditions and agronomic practices in their target
performance environments.
4. The highly specific nature of phenotypic response dictates
that effective studies of this aspect of diversity be carefully
designed with respect to functional traits, genetic sample, and
environmental treatments.