Dictionary > Etioplast

Etioplast

Definition
noun, plural: etioplasts
(botany) A plastid that developed in darkness or under low light conditions
Supplement
A plastid is an organelle that is commonly found in photosynthetic plants. Plastids are of different types depending on the presence of the pigment and metabolic functions. A chloroplast, for instance, is a plastid that contains high amounts of green pigment, chlorophyll. Etioplasts are plastids that arise from proplastids. Proplastids give rise to all the plastids in plants. Proplastids that turn into green and become photosynthetic develop into chloroplasts. However, those that are supposed to become chloroplasts become etioplasts when there is no light or when there is low light condition. The etioplast develop from a prolastid when it is grown in the dark. The development into chloroplast is arrested in the absence of light. Nevertheless, the etioplast can be converted into a chloroplast when there is an appropriate light exposure. Light exposure activates the plant hormone cytokinin, which in turn stimulates the synthesis of chlorophyll pigment.
Etioplasts have prolamellar bodies (i.e. a cubic lattice of interconnected membranous tubule network that arise from the inner plastid envelope) and few thylakoid membranes.1
Angiosperms grown in the dark or under low light condition would result in the increased concentration of etioplasts and this would cause the leaves to appear yellowish instead of green.
See also:

Reference(s):

1 Pessarakli, M. (1997). Handbook of photosynthesis. New York, NY u.a: Dekker. p392


You will also like...

Pink Lotus plant on a pond
Freshwater Lentic Communities & Animals

This tutorial looks at some of the communities in freshwater lentic habitats. For instance, symbiosis occurs in a commun..

Electromagnetic spectrum of a brain
Sleep and Dreams – Neurology

While learning and intelligence are associated with the functions of a conscious mind, sleep and dreams are activities o..

Lake Wakatipu, New Zealand
New Zealand’s Unique Geographical History

Explore why New Zealand has such unique flora and fauna, and learn why long periods of geographical isolation. This less..

Sensory systems
Sensory Systems

A sensory system is a part of the nervous system consisting of sensory receptors that receive stimuli from the internal ..

Geological Periods
Geological Periods

Geological periods is a study guide that cites the different geological periods on Earth's timeline. Each has a brief ov..

Biological Cell schematic diagram
Biological Cell Introduction

It only takes one biological cell to create an organism. A single cell is able to keep itself functional through its 'mi..