Storage of Sucrose and Starch in Plants
MUCILAGE CELLS
Water Storage in Plant Family
Cactaceae
Members of the Plant Family Cactaceae are exposed to an array of extreme conditions that make it difficult or sometimes impossible for other plant families to survive. With water being an essential part of plant survival, the question arises: How does this family thrive so well in high environmental temperatures and low rainfall?
COLLAPSING WATER STORAGE CELLS
When plants feel the stress!
Cactaceae Plant Adaptations for Water Storage
- Mucilage Cells: Contains the carbohydrate mucilage which binds to water tightly. The cells contain a sticky sap that helps provide water for other parts of the plant when necessary.
- Collapsible water storage cells: Have an inner water storing region and an outer photosynthetic layer. Has flexible walls that shrink and expand depending on water potential and distributes water to other cells when needed.
Summary: What's the bottom line?
Starch and sucrose are particularly saved for when the plant is in desperate need of energy such as in lack of sunlight. Starch acts as glycogen does for humans, it is a emergency reserve in dire situations. Plants are unable to store glucose because of its high solubility.
Using the Stored Goods
- Starch and sucrose are used by the plant via respiration
Electron Transport Chain creates molecular oxygen
Allana Dixon
Student #000-07-9132
Plant Physiology- BIO365
Professor: Jelena Andrejic
Carbon Dioxide via oxidation of pyruvate (citric acid cycle)
ATP (energy for the plant)
Pyruvate via the glycolytic pathway
Introduction
Energy Storage: Rainy Day Precautions
Plant Stress
As with all organisms, plants require energy and carbon matter to sustain life and initiate growth, but many stresses such as water deprivation, nutrient deficient environments and uprooting and strain on the plant structure can tamper with photosynthesis (the main means by which plants obtain energy). How then do plants combat energy deficiency and survive when faced with stress?
Plant stresses can be separated into two categories: Biotic and Abiotic
- Plants store glucose in response to stress in the form of starch. Photoassimilates, which are carbon compounds, are converted to starch and sucrose via carbon allocation.
- Because glucose is soluble and can pass through cells in the leaf, it must be converted to starch as it is insoluble in nature.
- Starch is biosynthesized in the stroma
- Sucrose is biosynthesized in the cytosol.
- Abiotic Stress would be physical and chemical insult that the environment may impose on a plant e.g. light and temperature
- Biotic stress would be a biological insult to which a plant may be exposed e.g. insects and disease
Plants must be able to acclimate when faced with these stresses