Molecular interaction kinetics and mechanism study of phytohormones and plant protein with fluorescence and synchronous fluorescence techniques

Cytokinins (CTKs) are widely used in agriculture to enhance crop production. To understand the role of CTKs in plant growth is vital, however, molecular mechanisms underlying CTKs action particularly their binding kinetics with proteins are not clear. The study of these interactions can obtain important information on how these signal molecules regulate cellular processes in targeted cells locally or transport to other functional parts of plants. In this study, the interactions between two CTKs and soy protein were investigated. The binding constants determined at 30 °C were Kκᴛ-ѕᴏу = 1.5×10³ M⁻¹ and Kıᴘ-ѕᴏу=0.67×10² M⁻¹ and the binding stoichiometry was nκᴛ-ѕᴏу=0.530 and nıᴘ-ѕᴏу=0.5165 respectively. Moreover, the CTK-protein interaction is found to be a static quenching process via an energy transfer mechanism. The adduct formed through electrostatic interactions under the plant acidity conditions was thus transported to the action parts of the plant to control growth process. Copyright © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.