Auksin. Other functions auksina

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Except control of a stretching of cages auksin can initiate also cell fission or promote it. If normal cages, for example a stalk or a root to grow up a method of culture of fabrics in the certain chemical environment cell fission will depend from auksina, developed by cages or present at the environment. beginning similarly kambialnoj activity at trees is partially supervised auksinom, diffundirujushchim downwards from developing kidneys in the spring. The bookmark of additional or lateral roots in a pericycle zone is in roots and stalks partly under the control auksina. This activity inducing a mitosis is carried out auksinom together with other group of vegetative hormones - tsitokininami which will be considered later. Auksin not only supervises initsiatsiju kambialnoj activity, but, probably, defines also the nature of the cages differentiated from kambialnyh of products. Presence auksina in kambii on the party turned to ksileme (mainly in young differentiated elements ksilemy on which it is transported from a stalk top), promotes development kambialnyh derivatives on this party kambija in ksilemnye cages. on an outer side kambija high concentration of sugars and gibberellinov in mature floeme cause development present here kambialnyh derivatives in floemnye cages. As we will see later, gibberelliny are produced basically by the young revealed leaves and consequently usually are in floeme together with the sugars formed at photosynthesis.

In the runaway separated from a plant, polar transport auksina, synthesised by a top, leads to its accumulation in the stalk basis. To similarly it auksin, put on runaway, also collects in the basis.

After a while here under action auksina there is a flow formation, or kallusa, containing set parenhimatoznyh the cages formed at division kambialnyh of cages in the basis of a stalk. Such kallusnaja the fabric usually nedifferentsirovana, but can contain randomly focused vascular elements. Often after activation kambialnyh cages auksinom additional roots much develop. This effect is widely used in fruit growing for reproduction of desirable plants by rooting of shanks.

Surprising transformation zavjazi in a fruit - one more supervised auksinom process. Usually after pollination and fertilisation the wall zavjazi of which the fruit finally is formed, starts to expand extremely strongly thanks to increase as numbers of cages, and their sizes. Sharp increase of its maintenance testifies to a certain role auksina in this process in zavjazjah and fruits during their development and that application ekzogennogo auksina at a well-chosen moment can accelerate all this process, and at some kinds even to replace usual pollination. If pollen has not reached a pestle development zavjazi it is possible to stimulate with drawing on it enough considerable quantities synthetic auksinov that leads to formation ' artificial ', or partenokarpicheskih, fruits .

b-Нафтоксиуксуеной acid, for example, it is possible oprysnut or to smear zavjaz a tomato. Typical enough fruit - red colour, large and tasty, but without viable seeds is as a result formed. As pollen contains a little auksina, its function partially should consist in synthesis activation auksina, probably, by entering in zavjaz any stimulator of the enzyme responsible for formation auksina from its predecessors.

Till now we considered stimulating influence auksina on division, a stretching and differentiation of cages. But auksin can render also and ingibirujushchee or limiting action on growth of separate parts of a plant. So, it influences a competition between different kidneys of a stalk. At plants with strong apikalnym domination only top kidneys whereas growth of underlaying kidneys is suppressed grow. At removal of top kidneys starts to grow one or several underlaying kidneys, and one of them usually becomes dominating. But if after removal of a top kidney on a cut surface to put a quantity auksina lateral kidneys do not develop. From here it is possible to draw a conclusion that auksin, arriving from apikalnoj kidneys, suppresses development of lateral kidneys. Last fact testifies that ' the decision ' about inhibition or stimulation of growth of lateral kidneys is accepted proceeding from competitive action at least two rostovyh hormones - auksina, going from apeksa, and tsitokininov, arriving, possibly, from root system. Therefore even in the system suppressed formed top kidney auksinom, local drawing tsitokininov on an oppressed kidney can cause its selective growth. If the lateral kidney managed to overcome inhibition auksin at repeated drawing already more does not depress it and can even strengthen its growth.