Title : The effect of Tetraneura ulmi L. galling process on the activity of amino acid decarboxylases and the content of biogenic amines in Siberian elm tissues
Abstract:
This report describe the changes in the content of plant biogenic amines (putrescine, cadaverine, spermidyne, tryptamine, spermine and histamine) and key enzymes of their biosynthesis: lysine decarboxylase (LDC), tyrosine decarboxylase (TyDC) and ornithine decarboxylase (ODC) in galls and other parts of Siberian elm (Ulmus pumila L.) leaves during the galling process induced by the gall-forming aphid Tetraneura ulmi (L.).Three stages of gall development were studied: the 1st stage – the initial period of galling -galls were green, about 5 mm in height with one fundatrix larva inside; the 2nd stage – the galls were green and fully grown with fundatrix and her young offspring inside; the 3rd stage involved the time period just before the gall opening. The direction and intensity of the observed changes for particular amines and enzymes were dependent on the stage of gall development and part of the galling leaf. Generally, the amine content tended to increase in gall tissues during the 1st and 2nd period of galling process and decreased in later phase. LDC and ODC activities were markedly enhanced, especially in gall tissues at the initial stage of the galling process. Moreover, the level of the majority of the analysed amines was reduced in damaged and undamaged parts of galling leaves during the initial period of galling process and at the time when the galls were fully developed. The participation of biogenic amines in the gall formation in Siberian elm leaves infested by T. ulmi is discussed.
