Antioxidant Activity Of Indolebutyric Acid And Its Effection On The Antioxidant System Of Coconut And Longan

Indole derivatives were generally believed to have strong antioxidant activity, but indole-3-butyric acidis roling in plants usually located as plant hormones. There was a black area on the investigation of its impact on plant antioxidant system. On the basis of the research progresses, this paper studied the antioxidant capacity of IBA by using morphology, physiology and biochemistry methods. At first, this paper studied the antioxidant activity of IBA in vitro, and investigated its influences on the antioxidant system in arabidopsis which model plant with shorter growth duration. Then the effects on the antioxidant system were further studied in tropical fruit tree such as Coconut (Cocos nucifera L.) and Longan(Dimocarpus longan Lour) to confirm previous conclusion. Finally, in order to simplify the detection of IBA, an effective and novel electrochemical detection method was established. The main results were concluded as follows:1.Adopted a different system of free radical to study the antioxidant capacity of IBA molecular itself and possible mechanism, the results show that the IBA had a much more excellent activity than NAA or2,4-D, especially on DPPH、OH·.and H2O2. Meanwhile, the metal chelating activity is almost the same as gallic acid, but the reducing power was relatively weak.It followed IBA antioxidant mechanism associated with H transfer and complexing ability.2.The study was also to investigate the protective effects of IBA on the antioxidant system in Arabidopsis thaliana. We discovered that the increasing of GSH and decreasing of MDA in IBA treatment. Also, the enzyme activity of POD, CAT and APX were greatly influenced by the concentration, the result showed that at a concentration of2mmol/L could enhance the enzyme activity significantly.3.IBAcould improve the activity of three enzymes coconutseedlings SOD、 CAT、APX, decreased the content of MDAin the plant stress, but had smallereffect on the activity of POD.The exogenous treatment of IBA would strengthen the balance of antioxidant system in longan seedlings. The GSH content and the enzyme activities including SOD and POD increased significantly when treated by2-3mmol/L and improved the body art ability.4.In the process of IBA treatment samples of longan, ASA-GSH loop main enzymes APX、MDHAR、DHAR activity increases, ASA and GSH content increasing, but the sample does not change significantly endogenous H2O2content and activity of GR.5.IBA in the B-R buffer solution has maximum tension peaks in the dropping mercury electrode scanning process at-500and-600mV(versus Ag/AgCl), the peak current increase along with the concentration, on the basis of scanning voltage, scanning rate, preconcentration time.etc, a simple and rapid IBA analytical method which was based on the hanging mercury electrode has been built.To sum up, IBA molecule itself has antioxidant activity, not only to use as a plant hormone, can also be involved in the regulation of plant antioxidant balance.