Shedding (abscission)

the natural separation of organs (leaf, bud, flower, fruit) from the mother during growth and development. It can be activated by signs of aging or maturation and the environment, such as shortening the length of the sun. Deterioration of external conditions, such as lack of moisture or inorristed nutrition, can also be caused. It is an adaptive manifestation and is conducive to the preservation of plant species. The leaf handle and flower handle of the geminal plant generally have an out-of-area at its base. Thin-walled cells that make up the off-zone zone are usually smaller than the surrounding cells, and individual tube molecules are shorter, in addition, there may be no fibers in the tube bundle. Endogenetic ethylene has been shown to be the main hormone used to control leaf
off
. Aging cells at the far axis end of the region produce relatively high levels of ethylene, and there are special target cells that react to ethylene at the far axis end of the region, under the effect of ethylene, these cells expand and produce and secrete (through the mass membrane only or mainly to one side wall secretion) more Glyphosate enzymes (including poly-semi-lactate acidase and cellulose enzymes), due to the catalytic activity of enzymes, make the wall of the middle adhesive layer and cell wall substate structure loose, cell soft and non-bonding with the far axis end cells to form an ionosphere. At this time only by the tube bundle connection, after the leaves fall off is purely mechanical action, not only the role of gravity and wind, but also the above-mentioned expanded cell pressure, as well as aging
tissue
dehydration, combined into a broken mechanical force. It has been pointed out that leaf aging can lead to its shedding, is due to the reduction of the amount of leaf synthetic growth hormone, through the leaf handle output is also reduced, so that the content of out-of-area growth hormone decreased, this decline can make the out-of-area cells more sensitive to ethylene, causing the effect of the above-mentioned ethylene. During the active life of the leaves, the leaf synthetic growth hormone is exported out through the leaf handle, and the leaves do not fall off, which is thought to be due to the loss of ethylene sensitivity of the out-of-area cells due to growth hormone. Therefore, both ethylene and growth hormone are involved in the control of leaf shedding. It is now thought that the control effect of shedding acid is very small.