Question

During seed germination, large quantities of triacylglycerol in the form of oil are accumulated in this organelle

• A. Pro-vacuoles
• B. Sperosomes
• C. Oleosins
• D. Secretary vesicles

Hint:

Remember that spherosomes are bounded by a single-layer phospholipid membrane, which is unusual compared to double-membrane organelles like mitochondria and plastids.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Oilseed plants store energy in their seeds as lipids, primarily triacylglycerols (TAGs).
These lipids are stored inside specialized, membrane-bound organelles that are mobilized during germination to power seedling growth.

Step 2: Detailed Explanation:
- Spherosomes (also known as Oleosomes or lipid bodies): These are spherical, single-membrane-bound organelles specialized for storing lipids in plant cells.
- The single membrane of a spherosome is a phospholipid monolayer that prevents individual lipid droplets from coalescing.
- During seed development, massive amounts of triacylglycerols accumulate within these spherosomes.
- During germination, lipases localize to the spherosome membrane to hydrolyze the stored triacylglycerols into glycerol and free fatty acids.
- These breakdown products are then transported to glyoxysomes for $\beta$-oxidation and glyoxylate cycle reactions, which convert lipids into carbohydrates.
- Oleosins are structural proteins embedded in the spherosome membrane, not the organelle itself.
- Pro-vacuoles and secretory vesicles are not specialized for lipid storage.

Step 3: Final Answer:
The organelle that accumulates triacylglycerols in the form of oil is the spherosome.