Bioprospecting Fluorescent Plant Growth Regulators from Arabidopsis to Vegetable Crops

Abstract

The phytohormone auxin is involved in almost every process of a plant’s life, from germination to plant development. Nowadays, auxin research connects synthetic chemistry, plant biology and computational chemistry in order to develop innovative and safe compounds to be used in sustainable agricultural practice. In this framework, we developed new fluorescent compounds, ethanolammonium p-aminobenzoate (HEA-pABA) and p-nitrobenzoate (HEA-pNBA), and investigated their auxin-like behavior on two main commercial vegetables cultivated in Europe, cucumber (Cucumis sativus) and tomato (Solanumlycopersicum), in comparison to the model plant Arabidopsis (Arabidopsis thaliana). Moreover, the binding modes and affinities of two organic salts in relation to the natural auxin indole-3-acetic acid (IAA) into TIR1 auxin receptor were investigated by computational approaches (homology modeling and molecular docking). Both experimental and theoretical results highlight HEA-pABA as a fluorescent compound with auxin-like activity both in Arabidopsis and the commercial cucumber and tomato. Therefore, alkanolammonium benzoates have a great potential as promising sustainable plant growth stimulators to be efficiently used in vegetable crops.

Arabidopsis Root Development Regulation by the Endogenous Folate Precursor, Para-Aminobenzoic Acid, via Modulation of the Root Cell Cycle

“…Interestingly, using theoretical calculations and crystallographic analyses, it was reported that PABA in its anionic form (PABA − ) would bind the active site of the auxin receptor TIR1, similarly to the naturally occurring auxin, indole acetic acid (IAA) [ 37 ]. This led to the conclusion that PABA might act as a potential auxin-like plant growth regulator [ 37 , 46 ]. IAA indeed inhibits root growth even at very low concentrations (nanomolar range) [ 47 , 48 , 49 ], whereas PABA inhibition of root growth is visible from 50 μM (this study; [ 31 , 37 ]).…”

Arabidopsis Root Development is Regulated by the Endogenous Folate Precursor, Para-Aminobenzoic Acid, Through Modulation of the Root Cell Cycle

“…Interestingly, using theoretical calculations and crystallographic analyses, it was reported that PABA in its anionic form (PABA − ) would bind the active site of the auxin receptor TIR1, similarly to the naturally occurring auxin, indole acetic acid (IAA) [37]. This led to the conclusion that PABA might act as a potential auxin-like plant growth regulator [37,46]. IAA indeed inhibits root growth even at very low concentrations (nanomolar range) [47][48][49], whereas PABA inhibition of root growth is visible from 50 µM (this study; [31,37]).…”