Who was the first to extract auxin from plants?

1934 Dutch scientist Guo Ge.

Where is auxin produced?

In 1880, Darwin and his son, in their last book, The Ability to Move Plants, stated that the germ sheath of the Canary grass of the grass family lost its phototropic response when the tip was cut off.

His explanation is that when the seedling receives light from the side, the effect of the tip is transmitted downward, causing the growth rate of the light to be different from that of the backlight, which causes the bending to the light receiving side, so that the top does not show a phototropic response after cutting off.

In 1928, Winter experimentally proved that there is a growth-promoting substance at the tip of the germ sheath, called auxin. It can spread into small agar squares, and placing the resulting small squares back on the side of the cut of the coleoplasty with the tip cut off can cause the coleoplasts to bend to the other side.

And the curvature is roughly proportional to the amount of growth-promoting substances it contains. This experiment not only proved the existence of growth-promoting substances, but also created the famous "oat test" for the determination of auxin.

1933 fIndoleacetic acid was isolated from human urine and yeast, and after it could cause the coleoplasty to bend in the oat test, it was proved that indoleacetic acid is auxin, which is ubiquitous in various plant tissues.

Extended Information: The effects of auxin are:

1. Inhibit the departure area.

Cotton and fruit trees drop flowers, fruits and leaves are common phenomena in dicots. The shedding of buds in cotton is related to the supply of nutrients and also to hormone levels. When the content of auxin at the base of the bud stalk is high and the content of auxin at the proximal axis is low, the activities of cellulase and pectinase in the separation layer are inhibited.

2. Promote fruitfulness.

After flowering and fertilization, the auxin content in the ovary increases, which promotes the expansion of the ovary and its surrounding tissues, and accelerates the development of fruits. If the pistil is not fertilized and the ovary can obtain IAA in time, it can also induce the formation of seedless fruits in some plants.

3. Herbicides.

There are two types of herbicides:1

Selective herbicide, low concentration to promote plant growth, high concentration to inhibit plant growth, auxin concentration dicots are more sensitive than monocots, so it can be used as a herbicide for monocots in monocots field. 2.

Non-selective herbicides: kill all plants, such as glyphosate.

Where is auxin produced?

Synthetic parts: auxin is widely distributed in plants, almost all parts are present, but not evenly distributed, at a certain time, the content of a specific part is affected by several factors. Most of them are concentrated in the vigorous parts (germ sheath, meristems of buds and root tips, cambium, ovary after fertilization, young seeds, etc.), and very little in senescent tissues and organs.

Synthetic pathways. Hope you help. ^_

Where is auxin produced?

Synthetic parts: Somatotropin is widely distributed in plants, almost all parts of the cavity are available, but not uniformly distributed, at a certain time, the content of a specific part is affected by several factors. Most of them are concentrated in the vigorous growth parts (germ sheath, meristem of buds and root tips, cambium, ovary after fertilization, young seeds, etc.), while very few are in senescent tissues and organs.

a. Indoleacetic acid, i.e., auxin, is a trace organic matter synthesized from a specific part of the plant, and a is wrong;

b. The geotropism and apical dominance of plants are that high concentrations of auxin inhibit growth, and low concentrations of raw blind socks promote growth, which reflects the duality of growth grinding hormone, and B is correct;

c. In the case of weightlessness in space, auxin can be transported in polarity, and c. error;

d. The auxin distribution in the agar block is not affected by one-sided light.

Therefore, b

Auxin is produced in which parts of the plant Shenzakura wide type?

Auxin is produced in which parts of the plant Shenzakura wide type?

Auxin is produced in which parts of the plant Shenzakura wide type?

a. The chemical essence of auxin is indoleacetic acid, not protein, so the synthesis site is not ribosome, a is wrong;

b. The transport of auxin is not necessarily polar transport, such as non-polar transport can occur in mature tissues, b error;

c. The effect of different concentrations of auxin on the same organ is not necessarily the same, low concentration is to promote growth, and when high concentration may inhibit growth, C is wrong;

D. Various plant hormones are interrelated and jointly regulated, when auxin increases, it can promote the synthesis of ethylene, and when ethylene increases you, it can inhibit the action of auxin, so D is correct

Therefore, d