Phytohormone Profiling of Malus domestica and Chenopodium murale Hairy Root Exudate: Association with Allelopathic Effects

Compounds exuded from roots play a key role in regulating plant allelopathic interactions. However, phytochormone profiling of root exudates and their contribution to an overall allelochemical activity of specific plant species is neglected topic in allelochemical research. Hairy root growth media of two different species, the fruit tree species Malus × domestica Borkh. and the herbaceous weed species Chenopodium murale L. were collected and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). We found that most of the phytohormones exuded by the hairy roots of C. murale and M. domestica were associated with the acidic fraction (96.8