The Impact of Chloroplast Movement in Plant Cells

Plant growth and development are directly influenced by the movement and positioning

of the chloroplasts. Chloroplast movement is stimulated by varying external stimuli;

(Kadota, Sato and Wada, 1996) submergence, water stress, low temperature, etc. and among

these light-induced chloroplast movement is the most researched and commonly established.

Chloroplasts in photosynthesizing plant cells change their arrangement in response to irradiation

from light. This is believed to maximize their photosynthetic activity and minimize photo

damage. This essay will try to expand on the concepts of chloroplast movement in plant cells by

discussing the mechanisms involved and machinery employed through irradiated light settings &

light receptors, and cytoplasmic filaments including Ca+ flux & actins.

Firstly, chloroplasts found in plant species change their location in a cell in response to

ambient light settings. Particularly, the “concentration” of the admitted light plays an importance

to the movement and relocation of the chloroplast for specific arrangement in a cell. Low

fluence-rate (LFR) is generated by weak light and as a result(Haupt and Scheuerlein, 1990) it

allows the chloroplasts to seek the best position possible in order to receive the greatest light

absorption. In contrast high fluence-rate (HFR) forces the chloroplasts to move to a position

where lowest possible light absorption takes place, in order to evade photo-damage. (Serlin and

Roux, 1984) during high fluence irradiation the chloroplasts are situated in periphery and move

onto the anticlinal walls.

Secondly, chloroplast movement in plant species is revealed to be most effective under

blue light. In a model study involving Arabi...

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...mmary, I hope I was able to illustrate to you the concepts of chloroplast movement

in plant cells by discussing the mechanisms involved and machinery employed through

irradiated light settings & light receptors, and cytoplasmic filaments & actins. Chloroplasts,

basically modify their intracellular organization by exposing profiles to the irradiated light (low

fluence rate vs. high fluence rate). Light receptor(s) and phytochrome are implicated in the

mechanisms of chloroplasts rearrangement and movement. This is also established by the

mechanism of assembly and disassembly of actin filaments and flux of Ca+. In retrospect, actin

responsibilities are depended on light receptors. As you can see, the interconnection between all

these components in one way or another play a significant role in the mechanisms and machinery

of chloroplast movement.