Changes in endogenous auxin level during flower bud abscission process in Pistachio (Pistacia vera L.)

Authors : Muhammet Ali GÜNDEŞLİ, Salih KAFKAS, Murat GÜNEY, Nesibe Ebru KAFKAS

Pages : 71-82

View : 16 | Download : 6

Publication Date : 2020-02-01

Article Type : Research Paper

Abstract :The regulation of auxin insert ignore into journalissuearticles values(indole-3-acetic acid, IAA); level in plants is a complex mechanism and the concept is not completely understood. There are many lines of evidence suggesting that amino acid conjugates of IAA play a vital role in auxin homeostasis, but the involved plant enzymes are still under investigation. In the present study, the alteration in the levels of auxin and its conjugates in the different physiological stages and organs, as well as its role in flower bud abscission in Pistacia vera L., were investigated. The levels of the auxin and its conjugates, such as IAA, indole butyric acid insert ignore into journalissuearticles values(IBA);, IAA-Ala, IAA-Leu, IAA-Asp, and IAA-Glu, were analyzed by ultraperformance liquid chromatography-electrospray ionization-mass spectrometry insert ignore into journalissuearticles values(UPLC/ESI-MS/MS); technique. Among the auxin conjugates, IAA was the main conjugate and dominant indole detected in pistachio extract observed in this work. It has also been determined that quite a few organs of `Off-year` trees have higher auxin content than `On-year` trees. It was observed that the auxin level is low in fruit-bearing trees in both leaves and shoots. It affects fruit yield and fruit bud abscission and plays some role in the alternate bearing. Decreased levels of auxin were observed in most of the organs of `On-year` trees during kernel development resulting in bud abscission. This study shows that auxin conjugates play an important role in IAA metabolism, particularly in flower bud abscission and fruit kernel development.
Keywords : Auxin, conjugate, Pistacia vera L, alternate bearing