What is a Meristematic Tissue?
The meristematic tissue is the tissue in plants that contains cells capable of dividing to produce new cells. Meristematic tissues are found at the tips of roots and shoots, where they produce more plant material.
Meristematic Tissue is a unique group of cells found in plants. These cells are able to reproduce themselves and allow the plant to grow further. The process by which meristematic cells divide is called “apical dominance.” It’s interesting to note that these cells only divide when they come in contact with an appropriate hormone: auxin.
If an auxin does not bind with the meristematic cell, it will be inhibited from dividing any further, ensuring that the other side of the node only grows as much as it needs to. This type of auxin-signaling is called “negative feedback inhibition.”
Meristematic tissue is found in vascular plants. They contain actively dividing cells that produce new tissue and are certain types of stem cells. The active cell divisions that occur in the meristematic tissues are responsible for the plant body’s growth. These cells also give rise to specialized and differentiated cells, including flowers, fruits, leaves, and roots.
The growth in height that a plant produces during its lifetime is due to the meristematic tissue that is found at the tip of each node. The position of this tissue on the node can be described as being “apical,” which means it’s found at the tip or apex of the stem, or “lateral,” which means it’s found away from the apex and stem.
The cells within this tissue are normally undifferentiated, which means they have not yet specialized in a particular cell type. It’s to be noted that this tissue is present in both stems, roots, and leaves.
Meristematic tissue contains meristem cells. These are capable of dividing and growing in order to produce new plant material, which is needed for such things as new roots or stems. Meristem cells are sometimes compared in a plant to a “miniature stem.
Meristematic cells are also involved in the process of differentiation, which is the change from a general state to a more specialized cell type. The cells that will differentiate are found away from the meristem. They receive their instructions from these actively dividing cells within the meristematic tissue – which is why it’s also sometimes called “differentiation meristem.”
The role that differentiation plays is to ensure there are enough specialized cells available for particular functions, such as leaves or flowers. Meristematic tissue is also needed for the formation of new structures of a growing plant.
Meristem cells are actively dividing, which means they have more chances of being DNA mutations. Legitimate mutations that occur in meristematic tissues can sometimes lead to the production of a novel type of cell or tissue, particularly if it’s needed for survival. A new type of leaf might arise as a result of one such mutation, or the plant could even produce a new kind of root-like what happened with the peanut.
The cells that divide in the meristematic tissue of plants are called “trophectoderm cells.” These cells are capable of producing numerous different cell types, which include shoot apical meristem (“SAM”) and root meristem (“RMA”). The plant body and parts of the plant, such as roots and stems, originate from SAM cells.
These divide to produce new buds on the end of the stem. The buds can then grow and produce new roots, which will eventually branch off to form the “phyllodes” of a plant.
The RMA cells at the base of the plant are responsible for producing new branches and roots. Due to this, it’s sometimes called “root meristem.” The RMA cell is also responsible for developing the arches that keep the stem upright. It’s also the site where the roots are formed and is therefore responsible for the future function of a plant’s parts.
Types of Meristematic Tissue
What are the different types of meristematic tissue
Meristematic tissue is always in either a dividing or non-dividing phase, but there are three different types of meristematic tissue: apical, lateral, and intercalary meristem.
- Apical Meristem: The apical meristem is the zone of cells at the tip of a plant’s shoot or root that is responsible for elongating and dividing to produce new cells, which in turn become either leaves or roots.
- Lateral Meristem: A lateral meristem is a group of undifferentiated stem cells found just beneath the plants’ epidermis layer, where they divide and differentiate into more specialized tissues such as bark, phloem, and xylem.
- Intercalary Meristems: An intercalary meristem is an area on a plant where growth can take place between nodes along a stem or branch; this type of growth occurs most often in trees with wide branches like oaks or walnuts but also in other plants like palms and grasses when their stems grow longer than their internodes (the spaces between individual nodes).
These categories are based on the growing tip’s location and its influence on the plant. The diagram shows a hypothetical plant that starts with a single growing tip. When the growing tip has grown into an elongated structure called a shoot, it becomes a lateral meristem. When it goes on to form a root system, the growing tip is considered an apical meristem.
Meristematic tissue comes in multiple layers that act like highways to transport nutrients and water throughout the plant. This transport system is known as phloem tissue and can be found on both stems (xylem tissue) and leaves (phloem).
Phloem is made up of cells called sieve tubes, microsporangia, and companion cells. The sieve tubes are the conduits through which nutrients and water travel to all parts of the plant. When the phloem is cut into slices, these slices work together as a map, mapping out where they need to go in order to help the plant grow. Sieve tubes may be seen as a vascular system located throughout stems and roots. Sieve-tube cells are living cells that undergo mitosis, increasing the amount of sieve-tube cells.
The companion cells are very similar in structure to sieve-tube cells, but they only function to support the sieve tube cell. The microsporangia are where pollen is produced and sent off from flowers. When pollen comes in contact with the female counterpart, it germinates, and the genetic material from both plants mix together, creating new offspring.
Microsporangia are the organs that allow achenes to germinate. It is the sole purpose of the microsporangium to produce pollen. The microsporangium has two buds that will germinate and produce new pollen to fertilize other plants.
In order for plants to produce roots, a shoot must be able to reach the water. A plant must have a vascular system to transport the water and nutrients. In plants, these are located in stems and roots. The phloem is the major vascular tissue of stems, and these are called the xylem. The xylem has different cell types depending on their position in the stem: bark, ring, big leaf, or thick-bark cells.
Much like sieve-tube cells and companion cells, apical meristem comprises many layers that work together to transport water and nutrients throughout the plant. It is located at the tip of the root or stem. A new xylem layer will be formed if the apical meristem has grown beyond its capacity to transport water and nutrients to other plant areas. The apical meristem will divide and push new stem cells down in order to make room for the water and nutrients.
As a plant grows, its meristematic tissue needs to expand to match that growth. Angiosperms (flowering plants) need to produce new meristematic tissue in order to expand.
The growth of meristematic tissue occurs through cell division or the mitosis of cells in the meristem. The outer cells of the meristem remain fixed and do not divide; instead, they enlarge to accommodate their growing contents. This creates a wave-like growth pattern within the plant.
Meristematic Tissue Function in Plants
The meristematic tissue in plants is mainly used for producing new stem tissue, but it can also be used to produce specialized cells such as root hairs or flowers. The meristematic tissue can provide plants with their ability to reproduce and expand, but the roots’ uptake is limited.
Meristematic tissue plays a large role in the development of plant bodies. The meristem is responsible for growth in stems, roots, and leaves. If stem structural cells in the meristem are unable to differentiate, then the plant’s ability to grow becomes limited. If specialized parts are not present, then the rate of growth will also be reduced.
The meristem allows for the growth of root hairs and storage reservoirs in roots, petals in flowers, fruit, and leaves. The capacity to perform all these functions is what makes a plant into an individual organism.
Good examples of this tissue’s effect on growth are seen in plants with dwarfism. If the meristematic tissue grows in patches, this can mean that it will be more difficult to get nutrients up through the plant’s stem. This will lead to the development of more patches in the stems, which can make the plant smaller
. Some plants have been found to have dwarfism that is caused by mutations in their meristematic tissue, with some mutations leading to the development of dwarfism. This has been witnessed in plants like rice and tobacco.
It’s also known that mutations to these tissue cause abnormalities like rhizomes being formed from stem tissue instead of roots and leaf deformities. Some mutations can cause the meristematic tissue to produce a lot of extra growth, resulting in the formation of tumors. Tumors are abnormal growths that develop as a result of abnormal cell division.
There are some interesting differences between plants and animals when it comes to meristematic tissues. In animals, the site where the cells divide is also known as a blastema. The blastema is responsible for producing new cells during development, with these new cells becoming specialized later on.
In plants, a similar tissue called the cambium is present. The cambium is located at various places throughout the plant, but it’s found in the meristematic tissue. This tissue continues to produce new tissues and cells to make up for any loss that the plant may experience. It allows for the woody portion of a plant to grow and divide.
The function of meristematic tissue in plants relies on the number of cell divisions that are happening. Plant cells can continue to divide and grow in meristematic tissue, allowing for the plant to grow. This process is necessary for plants to be able to grow and reproduce. However, this process can also get out of control if mutations are present in the tissue’s cells.
This could be caused by genetic errors or abnormal temperatures, or light conditions during growth. The result is that some plants, like annuals, are unable to survive year after year due to their meristematic tissues being unable to reproduce new tissues.
Some plants are able to survive year after year simply because they are perennial. Perennial plants go dormant during the winter, and they establish new meristematic tissue each spring. This allows for them to continue growing and reproducing. They have meristematic tissues known as parenchyma cells that help them to grow through cell division in their stems, leaves, and roots.
Perennial plants can also have meristematic tissues called apical buds or crown buds. These buds can produce new meristematic tissue in a short amount of time. Some plants, like the clones of apple trees, are associated with these buds.
For instance, a cutting taken from the rootstock of an apple tree has the ability to sprout into a whole new plant. These types of plants are called vegetative propagations.