The relationship between plants and mineral deposits, 15 kinds of mineral elements necessary for pla

Plants become mineral deposits when they are buried for a long time.

There are 14 kinds of mineral elements.

Among them, a total of 17 elements have been identified as essential for plants.

Among them, carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (mg), sulfur (S) and other 9 elements are required in plants in relatively large quantities, and their content in plants is relatively high (greater than less than 10mmol·kg-1 dry weight), which is called macroelements;

In addition, 8 kinds of elements, such as iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), molybdenum (Mo), chlorine (Cl) and nickel (Ni), also come from the soil, and the plant needs are very small (less than 10mmol·kg-1 dry weight), and a little more is harmful to the plant, and even causes its death, which is called trace elements.

In addition to C, H, and O, the remaining 14 elements are called essential mineral elements for plants.

Because some minerals contain certain trace elements that make plants grow luxuriantly, they can be used as indicator plants

Mineral elements refer to elements other than c, h, and o, which are mainly absorbed from the soil by the root system.

Regarding the mineral elements necessary for plants, it is written in the new edition of the high school biology textbook: "In the past, scientists determined that there were 13 kinds of mineral elements necessary for plants, of which N, P, K, S, CA, and mg are a large number of elements; Fe (also known as: semi-trace elements), MN, B, ZN, CU, MO, CL are trace elements.

According to the latest edition of Plant Physiology (Higher Education Press), it has been proved that there are 16 kinds of mineral elements necessary for plant growth, that is, Si, Na and Ni are also listed as essential mineral elements for plants, of which Si is a large number of elements, and Na and Ni are trace elements.

As an essential mineral element for plants, three conditions must be met: (1) If the element is deficient, the plant will have a disorder of development and cannot complete its life cycle. (2) When the element is removed, the plant exhibits a specific deficiency that can be prevented and recovered.

3) The element should be a direct result in plant nutrition and physiology, and by no means an indirect effect due to changes in the physical, chemical and microbial conditions of the soil or culture medium.

Si, Na, and Ni all exist in plants, but in the past, due to cultivation technology, impure drugs and other reasons, they were regarded as non-essential elements, but now their physiological roles are clarified, and they have the conditions to become essential mineral elements. The physiological effects of these three elements are introduced below for the reference of biology teachers.

Si accounts for the dry weight of the plant body, mainly in the form of orthosilicic acid (H4SiO4) in aqueous solution, and is absorbed and transported by the plant body in this form. Silicon is mainly deposited in the endoplasmic reticulum, cell wall, and intercellular space in the form of amorphous aqueous compounds, and can also form complexes with polyphenols to become thickened substances of the cell wall to increase the rigidity and elasticity of the cell wall.

Applying the right amount of silicon can promote crop growth and increase grain yield. When silicon is deficient, transpiration accelerates, growth is stunted, and plants are prone to lodging and fungal infection.

b helps in the germination of pollen as well as the growth of pollen tubes.

Na accounts for the dry weight of the plant body, is absorbed in ionic form, and is required for the growth of most C4 plants and sedum acid-metabolizing plants (e.g., sedum, ground roots, cactus, etc.). It catalyzes the regeneration of phosphoenolpyruvate. When sodium is deficient, these plants show yellowing and necrosis.

In addition, NA can also increase the turgor pressure of C3 plant cells, thereby promoting growth, and some NA can also replace the effect of K to improve the osmotic potential of cell fluid.

Ni accounts for the dry weight of the plant, and the main form of absorption is Ni2+. Nickel is a metallic component of urease. The role of urease is to catalyze the hydrolysis of urea into CO2 and NH4+. When NI is deficient, more urea accumulates at the tip of the leaf, and necrosis occurs.

In addition, Ni is also a component of nitrogen-fixing bacteria dehydrogenase.

The mineral elements that plants need the most are inorganic salts containing nitrogen, phosphorus, and potassium. Nitrogen fertilizer can promote the vigorous growth of the stems and leaves of plants, and phosphorus fertilizer can promote flower bud differentiation, early flowering and fruiting, and can make plants bloom more and bear more fruits, promote the growth of seedling roots and improve fruit quality. Potassium can promote the robustness of plant stems, improve fruit quality, enhance plant cold resistance, increase the content of sugar and vitamin C in fruits, and facilitate the transport of organic matter to plant storage organs. So chosen:

c。Inorganic salts play an important role in the growth and development of plants, including nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, manganese, zinc, molybdenum and other inorganic salts, among which plants need the most inorganic salts containing nitrogen, phosphorus and potassium.

Related to water, plants can only absorb mineral element ions dissolved in water, and cannot absorb mineral elements without water.

Root-related: the absorptive organ is the root. The absorption power is mainly ATP produced by root cell respiration, and the carrier consumes energy to do work.

The type and number of vectors on the cell membrane. The more a certain carrier, the more mineral element ions it carries are absorbed, otherwise there will be less.

The way in which plant cells absorb mineral elements.

Answer: The relationship between the absorption of mineral element ions by roots and the absorption of water.

These are two distinct but closely related physiological processes.

First of all, there is a clear difference between the two. One is the different mode of absorption: root cells absorb water by osmosis and diffusion, while mineral element ions are absorbed by active transport.

Second, the absorption power is different: the driving force for water absorption is the osmotic pressure composed of the transpiration pull force and the difference in solution concentration between the root cell and the environment; The driving force for the absorption of mineral element ions is mainly ATP produced by root cell respiration, and the carrier consumes energy to do work. Third, the relationship between the amount of absorption and the external concentration is different

Whether it can absorb water from the outside is determined by the relative concentration of the cell fluid and the external solution, when the concentration of the cell fluid is higher than the concentration of the external solution, the cell will absorb water, and vice versa, it will lose water; The amount of mineral element ions absorbed is determined by the type and number of carriers on the cell membrane.

Secondly, the two absorption processes are closely linked and inseparable. First, the absorptive organs are the same, that is, the main organs of resorption are all roots, and the most active parts are the cells (epidermal cells) in the mature zoneSecond, mineral element ions are generally dissolved in water in an ionic state and absorbed in an ionic state; Moreover, after the mineral element ions enter the plant body, they are also transported to various organs and tissues of the plant body along with water.

Third, after the mineral element ions are absorbed by the cell, it will affect the concentration of the solution inside and outside the cell, thereby affecting the water absorption of the root cell. Therefore, the absorption of mineral element ions by roots and the absorption of water are two relatively independent physiological processes.

There is a place in North America called "there is no return", because the strata and soil of this valley contain large amounts of selenium, and people and livestock can be poisoned and die if they eat food that contains a lot of selenium. It was decided to mine the selenium ore in the valley of "no return", and a large amount of milk vetch was planted. Milk vetch grows very quickly in such an environment and can be harvested several times a year.

After harvesting, people dry and burn milk vetch into ashes, and then extract selenium from the ashes, it is said that kilograms of selenium can be extracted per hectare of milk vetch, which is really a good way to "mine" mineral deposits.