The key difference between lenticels and hydathodes is that lenticels facilitate gas exchange and store gases, while hydathodes facilitate the removal of water and store water.
Plants follow different mechanisms to ensure their healthy and sustainable growth and development in various environments. They develop various adaptations to facilitate different functions during their primary and secondary growth phases. Lenticels and hydathodes, thus, act as pores and are two important adaptations in plants.
CONTENTS
1. Overview and Key Difference
2. What are Lenticels
3. What are Hydathodes
4. Similarities – Lenticels and Hydathodes
5. Lenticels vs Hydathodes in Tabular Form
6. Summary – Lenticels vs Hydathodes
What are Lenticels?
Lenticels are porous tissues composed of cells with very large intercellular spaces distributed in the periderm and the bark. They are mainly found in dicot plants. The main function of a lenticel is to act as a pore to provide a path for gaseous exchange in plants. The formation of lenticels begins at the stomatal complexes during their primary growth phase. They are found beneath the stomatal complexes at the periderm. The development of lenticels continues with the shoot growth. They are thus distributed along the stem as raised circular areas. In some cases, with secondary growth, lenticels may undergo discoloration with lignification. Lenticels may also adapt to different conditions. In mangroves, lenticels are present as pneumatophores, while in grapes, lenticels are present on pedicels.
Figure 01: Lenticels
Lenticels can also be found in fruits like apples and pears. The presence of lenticels in fruits increases the risk of microbial spoilage as microorganisms can more easily penetrate the fruits through lenticels.
What are Hydathodes?
A hydathode is a porous structure that mainly helps in secreting water. Hydathodes are usually located at the tip of the leaf margin in the epidermis. These pore structures are usually present in angiosperms but also distributed in submerged aquatic plants as well as herbaceous plants. Hydathodes are continuations of the plant vascular system. Hydathodes are commonly found in plants such as water lettuce, water hyacinth, and balsam.
Figure 02: Guttation from Hydathodes
The intracellular spaces of hydathodes are filled with water and form a water stoma or an open water stoma pore that can secrete water. The process of how hydathodes function is called guttation. This is mediated by the positive xylem pressure that causes water to exude from hydathode pores. Some halophytic plants also secrete salts through hydathodes.
What are the Similarities Between Lenticels and Hydathodes?
- Lenticels and hydathodes are present in plants.
- Both form pores.
- They are tissue structures developed into pores.
- Moreover, both are important adaptations in plants to ensure healthy growth and development.
What is the Difference Between Lenticels and Hydathodes?
Lenticels are pores that facilitate gaseous exchange, while hydathodes are pores that store water and take part in the guttation process. Thus, this is the key difference between lenticels and hydathodes. In addition, respiration is facilitated in lenticels whereas guttation is facilitated by hydathodes.
The below infographic presents the differences between lenticels and hydathodes in tabular form for side by side comparison.
Summary – Lenticels vs Hydathodes
Lenticels and hydathodes are the plant morphological adaptations that act as pores in plants. However, the key difference between lenticels and hydathodes is that lenticels store gases to facilitate gaseous exchange, while hydathodes store water to facilitate guttation. Lenticels are present underneath the stomatal complex, while hydathodes are present in the leaf tips. Moreover, the presence of lenticels helps to maintain the gaseous balance in a plant, but hydathodes facilitate the maintenance of the xylem pressure in the plant.
Reference:
1. J, Brown K; Considine. “Physical Aspects of Fruit Growth: Stress Distribution around Lenticels.” Plant Physiology, U.S. National Library of Medicine.
2. Jauneau, Alain, et al. “Anatomy of Leaf Apical Hydathodes in Four Monocotyledon Plants of Economic and Academic Relevance.” PloS One, Public Library of Science, 17 Sept. 2020.
Image Courtesy:
1. “European birch bark” By © Sue Sweeney – (CC BY-SA 3.0) via Commons Wikimedia
2. “Guttation-hydathode-nectarine” By Askune – Own work (CC BY-SA 3.0) via Commons Wikimedia
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