Accumulation of Indolyl-3-Acetic and Abscisic Acids by “Hairy” Roots of Artemisia vulgaris

Abstract

High-performance liquid chromatography–mass spectrometry has been used to study the character of the accumulation and balance of endogenous indolyl-3-acetic (IAA) and abscisic (ABA) acids in the “hairy” roots of Artemisia vulgaris obtained by transformation with Agrobacterium rhizogenes agropine strain A4. The free IAA content was significantly higher than the level of the conjugated form of the hormone. The highest amount of the active IAA form (554.4 ± 27.7 ng/g fresh weight) was detected in line no. 2. The free form of ABA predominated in the roots of control samples, where its level was significantly higher than in the transformed lines. The “hairy” roots accumulated a conjugated form of ABA, and the highest content of this compound amounted to 459.6 ± 23.0 ng/g of fresh weight (in line no. 4). The architecture of the transformed roots was marked by significant branching and lateral root formation; active accumulation of biomass was detected. The results obtained demonstrate changes in the endogenous phytohormone balance in the “hairy” A. vulgaris roots, namely, a trend to predomination of the free IAA form and a significant decrease of the ABA content.