Key Difference – Amphithecium vs Endothecium
In the context of the development of the sporophytes in plants, it takes place with the onset of fertilization. During plant fertilization, a zygote is formed. The zygote then undergoes different development stages where it actively divides and differentiates. Amphithecium and endothecium are two cell layers that develop with the onset of zygote formation and its differentiation. Amphithecium is considered as the layer present in the developing sporophyte that belongs to the group bryophyte. It involves the formation of the capsule wall. Endothecium is a central mass of cells in the rudimentary capsule that develops into a spore sac and initiates the formation of an air pocket between the layers of the endothecium and the wall of capsule. This is the key difference between the amphithecium and endothecium.
CONTENTS
1. Overview and Key Difference
2. What is Amphithecium
3. What is Endothecium
4. Similarities Between Amphithecium and Endothecium
5. Side by Side Comparison – Amphithecium vs Endothecium in Tabular Form
6. Summary
What is Amphithecium?
Ampethecium is defined as the cell layer that emerged from the developing sporophyte that initiates the development of the capsule wall in the plant division Bryophyta. In the context of bryophytes, they are non-vascular land plants that are characterized by the limited size with a preferential moist habitat. They contain enclosed reproductive structures. These structures are gametangium and sporangium. The developing capsule is also known as the sporangium where haploid spores are produced through meiotic division. The amphithecium contains one to several layers where a special layer gives rise to the development of the sporangium wall. This is referred to as the exothecium.
Figure 01: Amphithecium during the Development of Mosses
Therefore, the amphithecium plays a major role during the development of the wall of the sporangium (capsule). According to the type of bryophyte, the type of structure that is developed from the amphithecium varies. In the context of mosses, the amphithecium gives rise to the capsule wall and also to the peristome. The peristome is the collection of small projections that surround the opening of the capsule. In hornworts and peat mosses, the amphithecium gives rise to the capsule wall and the sporogenous tissue.
What is Endothecium?
The endothecium is a central mass of cells in the rudimentary capsule that develops into a spore sac and initiates the formation of an air pocket between the layers of the endothecium and the wall the of the capsule. When studying the cells present in the endothecium, they contain dense cytoplasms. No vacuoles are present. Due to these physical features, it is hard to distinguish one cell from the other. The dense cytoplasm is the major reason for this.
With regards to stamen of the lemon flower, the anther produces mature pollen grains. During the initial development of the pollen grains, the cell lining that presents in the lumen of the anther is also referred to as the endothecium. In this particular aspect, the function of the endothecium is to produce and secrete different nutritional materials that are essential for the proper development of the pollen grains. Under close observations, the endothecium and pollen grains contain red dots. These red dots denote the presence of nucleoli.
What is the Similarity Between Amphithecium and Endothecium?
- Both amphithecium and endothecium are cell layers of the developing plant tissues.
What is the Difference Between Amphithecium and Endothecium?
Amphithecium vs Endothecium |
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| The layer present in the developing sporophytes that belongs to the group bryophyte and involves in the formation of the capsule wall is known as the amphithecium. | Central mass of cells in the rudimentary capsule that develops into a spore sac and initiates the formation of an air pocket between the layers of the endothecium and the wall of the capsule is known as the endothecium. |
| Function | |
| The function of the amphithecium is the formation of the capsule wall. | The function of the endothecium is the formation of an air pocket. |
Summary – Amphithecium vs Endothecium
With the onset of fertilization, the development of sporophyte initiates. Fertilization yields a zygote. Differentiation of the zygote gives rise to amphithecium and endothecium. The amphithecium is considered as the layer that is present in the developing sporophyte that results in the formation of the capsule wall. In different species, the amphithecium gives rise to other structures other than the capsule wall. The endothecium is the cell mass in the rudimentary capsule that develops into a spore sac and initiates the formation of an air pocket between the layers of the endothecium and the wall of the capsule. It also functions to secrete nutritional factors for the development of the pollen grains. This is the difference between Amphithecium and Endithecium.
Reference:
1.“Endothecium.” Anther endothecium. Available here
2.Bahadur, Bir, et al. Plant Biology and Biotechnology. Springer, 2015.
Image Courtesy:
1.’The structure and development of mosses and ferns (Archegoniatae) (1918) (14782710514)’By Internet Archive Book Images (Public Domain) via Commons Wikimedia
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