`star` Differentiation, Dediffrentiation and Redifferentiation
`star` Development


● The cells derived from `color{violet}"root apical"` and s`color{violet}"hoot-apical meristems"` and `color{violet}"cambium differentiate"` and mature to perform `color{violet}"specific functions"`.

● This act `color{violet}"leading to maturation"` is termed as `color{Brown}"differentiation."`

● During `color{violet}"differentiation"`, cells undergo `color{violet}"few to major"` structural changes both in their `color{violet}"cell walls"` and `color{violet}"protoplasm"`.

● For example, to form a `color{violet}"tracheary element,"` the cells would `color{violet}"lose their protoplasm"`.

● They also develops a very `color{violet}"strong, elastic"`, `color{violet}"lignocellulosic secondary"` cell walls, to `color{violet}"carry water"` to long distances even `color{violet}"under extreme tension."`

● `color{violet}"Plants"` show another `color{violet}"interesting phenomenon"`.

● The `color{violet}"living differentiated cells"`, that by now have `color{violet}"lost the capacity"` to `color{violet}"divide"` can regain the capacity of division under `color{violet}"certain conditions"`.

● This phenomenon is termed as `color{Brown}"dedifferentiation."`

● For example, `color{Brown}"formation of meristems"` – `color{violet}"interfascicular cambium"` and `color{violet}"cork cambium"` from fully differentiated `color{violet}"parenchyma cells."`

● While doing so, `color{violet}"such meristems/tissues"` are able to divide and `color{violet}"produce cells"` that once again `color{violet}"lose the capacity to divide"` but mature to perform specific functions, i.e., get `color{Brown}"redifferentiated."`

● The `color{violet}"growth in plants"` is `color{Brown}"open"`, i.e., it can be `color{violet}"indeterminate or determinate"`.

● Now, we may say that `color{violet}"even differentiation"` in plants is `color{violet}"open"`, because `color{violet}"cells/tissues arising"` out of the `color{violet}"same meristem"` have different structures at maturity.

● The `color{violet}"final structure"` at maturity of a `color{violet}"cell/tissue"` is also determined by t`color{violet}"he location of the cell"` within.

● For example, `color{violet}"cells positioned away"` from `color{violet}"root apical meristems"` differentiate as `color{violet}"root-cap cells,"` while those pushed to the periphery mature as `color{violet}"epidermis"`.


● `color{Brown}"Development"` is a term that includes `color{violet}"all changes"` that an organism goes through `color{violet}"during its life cycle"` from `color{violet}"germination"` of the seed to `color{violet}"senescence"`.

● `color{violet}"Diagrammatic representation"` of the sequence of processes which constitute the `color{violet}"development of a cell"` of a higher plant is given in Figure.

● It is also applicable to `color{violet}"tissues/organs"`.

● Plants follow `color{violet}"different pathways"` in response to environment or `color{violet}"phases of life"` to form `color{violet}"different kinds of structures"`.

● This `color{violet}"ability"` is called `color{Brown}"plasticity"`, e.g., `color{violet}"heterophylly in cotton"`, `color{violet}"coriander"` and `color{violet}"larkspur"`.

● In such plants, the `color{violet}"leaves of the juvenile plant"` are different in shape from those in `color{violet}"mature plants"`.

● On the other hand, `color{violet}"difference in shapes"` of leaves `color{violet}"produced in air"` and those `color{violet}"produced in water"` in buttercup also represent the `color{violet}"heterophyllous development"` due to environment.

● This `color{violet}"phenomenon of heterophylly"` is an example of `color{violet}"plasticity"`.

● Thus, `color{violet}"growth, differentiation"` and `color{violet}"development"` are very closely related events in the life of a plant.

● Broadly, `color{Brown}"development"` is considered as the `color{violet}"sum"` of `color{violet}"growth and differentiation."`

● `color{violet}"Development in plants"` (i.e., both growth and differentiation) is under the `color{violet}"control"` of `color{violet}"intrinsic and extrinsic factors"`.

● The `color{violet}"former"` includes both `color{violet}"intracellular (genetic)"` or `color{violet}"intercellular factors"` (chemicals such as plant growth regulators) while the `color{violet}"latter"` includes `color{violet}"light, temperature"`, `color{violet}"water, oxygen, nutrition"`, etc.