Plant hormone theory II

Plant hormone theory II Auxin and Cytokinin are released any time nutrients go above survivable levels. Auxin is stimulated by above survivable levels of sugar and essential gases. Cytokinin is stimulated by above survivable levels of minerals and water. Auxin and Cytokinin being signals of nutrients levels, stimulates their use by increasing the speed of metabolism or inducing growth and cell division. GA and Ethylene are released when nutrients fall below that which is needed for peak metabolism. GA is released when sugar and essential gases fall below the level needed for peak metabolism. Ethylene is released when minerals and water fall below this peak level. GA and Ethylene then do their best to attempt to address the shortfall by decreasing the speed of metabolism, inducing cell dormancy and inducing senescence. As is well accepted by most plant physiologists, in this Second Theory ABA takes on the role of a "Shock" Hormone. That is it would be induced by rapidly developing threats to plant survival and would put them in a defensive and dormant mode making them more impervious to the threat. As is beginning to be accepted Salicylic Acid here would be kind of the "All Clear" Hormone returning the cell to normal functioning after a serious threat of some kind. Because Auxin is an indication that the levels of sugar and gases are above survivable levels, it increases that part of metabolism that uses sugar and gases. This partial increase in metabolism will cause an increase in the need for the complimenting water and mineral nutrients in order to round out an increase in metabolism. If water and minerals are not in adequate supply they will quickly decrease and this will cause an increase in the amount of Ethylene. Ethylene puts brakes on that part of a cell metabolism involved with water and minerals. Thus an artificial stimulation of that part of metabolism dependent on sugar and gases by adding Auxin to a plant, will lead to an emanation of Ethylene. This is especially so in the root where that part of metabolism dependent on sugar and gases is less likely to be operating at peak levels. Of course this argument is somewhat specious because that part of metabolism connected with water and minerals should be already operating at full throttle in the root. The attempt of course here is to describe why scientists have found that Auxin leads to Ethylene emanation more quickly in the roots than the shoots. Perhaps I have the details wrong here, but maybe someone using the concepts introduced here, could tease out a satisfactory explanation. Because Cytokinin is an indication of at least survivable levels of water and minerals, it increases the speed of metabolism of that part of metabolism that depends on water and metabolism. This naturally leads to an increase need for the complimentary nutrients, sugar and gases. Thus the emanation of Gibberellin will occur if the supplies of sugar and gases are inadequate. I believe GA puts brakes on that part of metabolism that uses sugar and gases. The artificial raising of the levels of CK will induce GA especially in the shoot. There is a problem here too though because as explained before, that part of metabolism depending on sugar and gases should be at full throttle in the shoot. Whenever nutrient levels fall between peak metabolism and survivable nutrient levels, we can expect both Stress and Growth Hormones to be synthesized. Since shoots are the organs that make sugar and harvest essential gases, we can expect that levels rarely fall below peak metabolism nutrient levels. Thus we can expect that Gibberellin is rarely synthesized in the shoot. I know there is supposedly experimental evidence that this is untrue, but perhaps it should be looked at again more closely. This is not to say that GA is not found in the shoot. From the definition of a hormone we can expect that the effect of a hormone occurs at a distant location from its synthesis. I would expect GA to be mostly made in the root where sugar and essential gases may often fall below peak metabolism levels. Synthesis may occur in the roots, but the effects GA has are in the shoot as well as the root. As in the first version of theory, I believe all of GA's effects are meant to address shortfalls in sugar and essential gases. This would include root growth inhibition and senescence, shoot lengthening, shoot preservation from senescence, and the changing of photosynthesis from C3 to C4 (which I believe is more efficient but builds up toxins in the leaves). Thus on the converse, we can expect Ethylene to be rarely synthesized in the root, where levels of minerals and water seldom fall below those needed for peak metabolism. This is not to say that similar to GA and the shoot, that Ethylene does not have a big effect on roots. Again just like in the first theory, I believe everything Ethylene does is to address nonideal levels of minerals and water. Thus Ethylene inhibits shoot and leaf growth, induces leaf senescence, initiates the somewhat risky growth of root hairs, preserves roots from senescence and causes roots to branch out and to make new lateral growth in the soil. This is at least what would be true during the day. Some kind of converse or complimentary situation would exist at night when few nutrients are synthesized or harvested. So for instance GA and Ethylene would be at high levels at night in both the root and shoot with Auxin at some level in the shoot and rarely found in the root at night. Conversely Cytokinin would be synthesized in the root at night but rarely in the shoot or only in the beginning of the period trailing off as the night progresses. In this scheme, it is fairly clear what would be a signal for growth. It would be the existence of fairly high levels of Growth Hormones (Auxin and Cytokinin), and the lack of existence of the Stress Hormones (GA and Ethylene). Conversely the signal for the presence of senescence conditions would be the presence of Stress Hormones and the absence of Growth Hormones. This would signal the lack of survivability of cells in that local tissue. If there is a linear relationship between the levels of sugar and gases and Auxin we should expect to be roughly twice the level of the hormone in the shoot as the root. This is because the shoot is making sugar and harvesting gases not just for itself but also for the root. It makes or harvests two parts, keeps one for itself and sends the other to the root. The same would be true if there is a linear relationship between minerals and water and Cytokinin. Experimental evidence suggests that a linear relationship does not exist but more likely a logarithmic scale of some sort. The idea would be that the amount of Auxin in the shoot would be some power of say 2 of the amount that is found in the root. Let's say it is the square. Thus there would be 4 times the amount of Auxin found in the shoot as in the root. Thus Auxin can be seen as primarily a shoot hormone. As mentioned in Theory I it has been found that Auxin is found to be synthesized in much greater amounts in young leaves than mature leaves. As in the previous theory I believe the relative levels of synthesis of all hormones holds for this one too. Thus Auxin is made the most in young leaves and the least in mature roots. Cytokinin would be made the most in young roots and the least in mature leaves. GA would be the synthesized the most in mature roots and the least in young leaves. Ethylene would be synthesized the most in mature leaves and the least in young roots. I also believe the relationship holds of Growth Hormones attracting all nutrients and hormones to itself excepting Ethylene and GA and the Stress Hormones pushing out all nutrients and hormones excepting Ethylene and GA. In this scheme we can also postulate an explanation for cell dormancy like the dormancy that exists in secondary buds. That would be perhaps at low levels GA and Ethylene in addition to the direct causation of dormancy, would attract all nutrients instead of pushing them out. On the other side, perhaps at low levels Auxin and Cytokinin would push nutrients out of a cell. Thus a dynamic yet stable equilibrium would exist at very low levels of nutrients. The movement into real metabolism or back toward senescence would need amounts or deficiencies in nutrients beyond which caused the synthesis of GA and Ethylene acting in their nutrient attraction mode, and Auxin and Cytokinin acting in their nutrient pushing mode. Perhaps another similar equilibrium exists at the peak metabolism point.