Prof. Dr. Fatih SATIL
Balıkesir University, Faculty of Arts and Sciences, Biology Department, Balıkesir.
[email protected]

In plants, a special transport tissue is needed for the water, the substances dissolved in the water and the substances produced in the leaves to reach the relevant organs. Starting from the roots of the plant, this transport tissue should proceed to various organs above the ground and extend to the furthest point. There are two types of transport tissues with different structures and functions in plants. They are called Xylem (wood vessel), which transports water and inorganic substances dissolved in water and Phloem, which conveys nutrients.

Water-transporting wood vessels are ultra-capillary tubes created with the most suitable design to carry the water required for plants several meters up from the plant roots (Figure 1). These capillaries undergo regular stages of differentiation from the initial formation to the development stage.

                       A                                                        B

Figure 1: Wood vessels that transport water in plants. A: Appearance in vertical section, B: Appearance in cross-section (Bar: 20 µm).

Transportation of water in the transport tissue takes place as a result of the elongation of the conducting cells in the direction of transport,the expansion of the transverse wall surfaces of the elongated cells as much as possible and the complete elimination of the transverse walls in those cells.[1]

Water pipes in charge of transporting water in plants are the ultra-capillary pipes where water is transported from the plant roots to the highest point. Those pipes are composed of long dead cells that are lined up in the direction of transmission that lost their protoplasts in the adult phase and whose walls were lignified. Thickening is formed on the walls of these elements, which appear circular or polygonal in cross-sections, in order to increase resistance and strength.(Figure 2)

Figure 2: The inner structure of water transport vessels in plants (Cross-section, Bar: 60 µm).

Regardless of the size of the plant, the diameter of these pipes constituting the transport system is approximately 0.25 mm in oak (Quercus sp.) and 0.006 mm in lime (Tilia sp.). These pipes, which are called wood vessels, are of two types: trachea and tracheid: Tracheids are dead cells with a sharp tip, narrow diameter, that are closed and approximately 1 mm long. Tracheasare tubular dead cells that are shorter and wider in diameter than tracheids and that are open. [2]

The Evolution of Wood Vessels

Wood vessels are formed from meristematic cells arranged lengthwise in the cambium. These capillary tubes display regular developmental stages from their initial formation to maturity.

These pipe cells,which are initially live, have been programmed to be dead cells. When these cells are evolved based on a plan, they lose their protoplasts completely; their transverse walls melt; they become hollow and dead pipe cells. The genetically programmed cell death in the differentiation of wood vessels in this way is called apoptosis.[3]

It is necessary for those cells to die so that the water will be actively transported. How does it happen? When does it happen? Who decides when it will happen? They are very important issues.

Apoptosis in wood vessels occurs based on a plan. The cytoplasm and the nucleus take the peripherical position under the cell membrane. The lower and upper walls of the cell begin to melt. This task is assigned to enzymes that dissolve the transverse walls. Then, the cells lose their protoplasts completely; the transverse walls between the cells melt.Finally, large and hollow cells in the form of dead pipes form. (Figure 3).

Figure 3: The development of wood vessels that transport water in plants (Yentür, 2003).
Longitudinal section. The young cells are on the left. They expand gradually, lose their cytoplasm and nuclei; the membranes between the cells melt and they are transformed into transport pipes.

Doubtlessly, these differentiation events in highly complex cells are not the work of genes, hormones and chance that lack intelligence and consciousness.

The differentiation is explained by plant physiologists and molecular biologists as the activation and repression of the genes in cells depending on time and conditions.[4]

In that case, how is it decided that differentiation is necessary and when it will start and stop?

The activation and repression of genes are also controlled by hormones. The roles of Auxin and Cytokine hormones in initiating differentiation in those cells have been proved in several morphogenetic studies. However, the synthesis and control of these hormones are also under the control of the genes involved.[5]

This brings the following question to mind: “Are these events under the control of genes or hormones?”In conclusion, the differentiation in cells has not been fully explained yet.

Doubtlessly, these differentiation events in highly complex cells are not the work of genes, hormones and chance that lack intelligence and consciousness.

As it is the case in the design of the water transport pipes in plants, this biological phenomenon, which is very deep, unknown and very important, and which contains numerous wisdoms,has been tried to be explained with scientific names like“control of genes”, ”totipotency in cells” and “hormonal orientation”.

However, it is not an explanation but naming. To give a name to an unknown fact that is so deep and great that even if it is described in a hundred pages and the wisdoms behind it are explained can hardly be knownas if it is something known and to say ,”That is it” by attributing incidents to chance and nature means to hidethe wonderful power that works behind those miracles.

The Wisdom Behind the Evolution of Wood Vessels

There is a very important reason for this evolution in wood vessels. It is necessary for water to move freely in vessels without encountering any obstacles while being transported in vessels. In order to achieve this, the cell must be transformed into a completely empty vessel. In addition to this change, the hollow region of the cell is created in accordance with the hollow of the next cell so that they can be easily connected to each other. Thanks to this harmony, the cell extensions are transformed into a series of pipelines along the body (Figure 4).

As it can be seen, wood vessels were created in the most appropriate design to carry the water required for plants several meters up. The criteria for this design in water vessels with a diameter of approximately 0.25 mm-0.006 mm are as follows:

  • The inside of the cells must be empty so that the water can be easily transported without encountering any obstacles.
  • These cells, which are smaller than 1 mm, must be connected with each other.

Figure 4: The structure of the wood vessels transporting water in plants (A, B, C: Longitudinal section, D: Cross-section) (Bar; A: 200 µm, B: 40 µm, C, D: 5 µm).

  • Cell connection points must be compatible.
  • They must not leak water.
  • They must be resistant to pressure and decay.
  • They must be resistant to bending and adapt to the growing plant.

Can these designs, which require great knowledge and wisdom, be explained by chance and causes?

The Inner Design of Wood Vessels

The walls of the wood vessels are quite thick because water is to be transported through absorption and under a certain pressure with this vessel system in the tree. The vessels must resist this negative pressure, which is quite strong. There is also a need for a waterproof solid material that is resistant to decaying. Therefore, the wall of the water vessels is made of solid material that can withstand pressure.

The Material Used in the Inner Design of Water Transport Vessels

The side walls of the water-transporting vessels is transformed into a durable and waterproof structure with the addition of a solid material called lignin (wood). Lignin that accumulates in the cell wall protects the vessels against pressure and decaying in addition to being waterproof.

There are questions to be answered about the formation of this structure. They are as follows: 

  • Why is lignin used though there are many different wall materials?
  • How was it determined that such a material is suitable for this task?
  • How is the pressure generated by the water to be transported in the water vessel calculated?

The water vessels in plants need to be flexible in order to be resistant to bending and to adapt to growing plants. Wood vessels are designed in accordance with those circumstances with special thickening in the form of rings, spirals, and webs in the inner part of the side walls (Figure 5). This design allows the cell, tissue and organ lengthen, grow and stretch.

It is necessary to know several sciences such as construction science, building materials science, physics to calculate pressure, biochemistry, physiology, systematics, anatomy and morphology in order to make all those designs.However, dead cells, which we call wood, have neither reason nor life to know them.

                      a                                         b                                     c

Figure 5: Inner wall design of wood vessels. a. The cross-section of the inner appearance of vessels b, c: Inner wall thickening types of vessels (Bar: 10 µm).

In conclusion, this structure cannot be made by anyone but a being with endless wisdom, unlimited power and comprehensive knowledge.

This measure and system in the formation of wood vessels shows us the Almighty Creator, who has infinite knowledge and wisdom. The Quran indicates this fact in many verses:

It is Allah who created all things, and ordered them in due proportions”.[6]

“Verily, all things have We created in proportion and measure”.[7]

The evolution of water vessels in plants, which are planned and changed in a remarkably systemized manner and designed according to a special measure and plan cannot be explained by “spontaneity”,“ nature ”or“causes”. Nobody but a being with endless wisdom, unlimited power and comprehensive knowledge can establish this system and place it in the trees. Allah’s art of creation is expressed as follows in the Quran:

 “He is Allah, the Creator, the Evolver, the Bestower of Forms (or Colors) …”. [8]

These wood vessels, which are placed in every plant with Allah’s name of al-Batin (the Hidden One), are created in compliance with all tissues and organs of that tree and in precise measures.

The Wisdom behind the Non-existence of Wood Vessels in Some Plants

Only tracheids are found in ferns and open seed plants. Both tracheids and tracheas are present in closed seed plants (Figure 6). The existence or non-existence of tracheas and tracheids is directly related to the need for water. As it is known, open seed plants are coniferous. Since the sweating surface of the leaves is narrow, little sweating occurs. Such plants require less water. Therefore, only tracheids are sufficient to transport water in this group of plants.

However, closed seed plants are generally broad-leaved plants. Since the sweating surface of the leaves is large, water loss is more. The need for water is more. Therefore, tracheas also work in addition to tracheids in this group of plants.

This issue can be considered as an artist’s exhibiting different features in his art. The following is stated in verse 79 of the chapter of Yasin: “… He is Well-versed in every kind of creation.” Acting upon this verse, we can understand that the Creator can create plants with or without vessels, or that He can do different things related to the wood structure of different plants.

In conclusion, plants are created with the necessary equipment to meet their needs within the framework of the “principle of meeting needs” in accordance with their living environment.

They all show usthe existence of a being who knows, sees andmeets the needs of plants.

                                   a                                                              b    

Figure 6: Cross-sections from the wood of different plants: a) Open seed plants (Gymnosperm), b) Closed seed plants (Angiosperm).

Conclusion and Proposals

Biological Events cannot be explained by “Spontaneity” or “Randomness”.

As it is the case in this issue, most of the biological events are remarkably planned and programmed, and they are extremely complex. It is not a simple or two-stage event.

Behe (1996) tries to explain that “biological events are a necessity of a plan and program” with some biochemical examples he gives. “The Intelligent Design” theory, which was developed by Behe, which aroused great interest in the world, reveals with scientific explanations that the existence of beings does not happen by chance but based on the magnificent plan of knowledge, wisdom and power. When he does so, he explains the matter with purely scientific examples without giving a name about the doer and without mentioning revelation. However, at the end of all the examples, he displays the existence of a designer withinfinite knowledge and power.

In conclusion, it is a miraculous event that the water needed by the trees is transported from the soil to the furthest leaves without any interference from outside. The trees are equipped with a very detailed and perfect system so that this perfect activity will be realized. Water is transported through a system built from ultra-thin vessels extending from the roots of the tree to the trunk and branches. Doubtlessly, this is not the work of the trees or water molecules or chance that lack intelligence and consciousness. This system cannot have been placed in the trees by anyone except a being that has endless wisdom, unlimited power and comprehensive knowledge.


[1] Bollhöner B, Prestele J, Tuominen H. Journal of Experimental Botany, 63 (3): (1081–1094), 2012.
[2] Yentür, S. Bitki Anatomisi, İstanbul Üniversitesi Yayınları, 2003.
[3] Bollhöner B, Prestele J, Tuominen H. Journal of Experimental Botany, 63 (3): (1081–1094), 2012.
[4] Kocaçalışkan, İ. Bitki Fizyolojisi, Nobel Yayınevi, 2008.
[5] Kocaçalışkan, İ. Bitki Fizyolojisi, Nobel Yayınevi, 2008;
[6] al-Furkan, 25/2.
[7] al-Qamar, 54/49.
[8] al-Hashr, 59/24.

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