A plant-based chemical genomics screen for the identification of flowering inducers

Martijn Fiers,Alice Brunazzi,Jorin Hoogenboom,Gerco C Angenent,Tom Wennekes,Richard G H Immink

doi:10.1186/s13007-017-0230-2

Martijn Fiers, Alice Brunazzi + Show 4 more

Open Access

https://doi.org/10.1186/s13007-017-0230-2

Copy DOI

Abstract

BackgroundFloral timing is a carefully regulated process, in which the plant determines the optimal moment to switch from the vegetative to reproductive phase. While there are numerous genes known that control flowering time, little information is available on chemical compounds that are able to influence this process. We aimed to discover novel compounds that are able to induce flowering in the model plant Arabidopsis. For this purpose we developed a plant-based screening platform that can be used in a chemical genomics study.ResultsHere we describe the set-up of the screening platform and various issues and pitfalls that need to be addressed in order to perform a chemical genomics screening on Arabidopsis plantlets. We describe the choice for a molecular marker, in combination with a sensitive reporter that’s active in plants and is sufficiently sensitive for detection. In this particular screen, the firefly Luciferase marker was used, fused to the regulatory sequences of the floral meristem identity gene APETALA1 (AP1), which is an early marker for flowering. Using this screening platform almost 9000 compounds were screened, in triplicate, in 96-well plates at a concentration of 25 µM. One of the identified potential flowering inducing compounds was studied in more detail and named Flowering1 (F1). F1 turned out to be an analogue of the plant hormone Salicylic acid (SA) and appeared to be more potent than SA in the induction of flowering. The effect could be confirmed by watering Arabidopsis plants with SA or F1, in which F1 gave a significant reduction in time to flowering in comparison to SA treatment or the control.ConclusionsIn this study a chemical genomics screening platform was developed to discover compounds that can induce flowering in Arabidopsis. This platform was used successfully, to identify a compound that can speed-up flowering in Arabidopsis.

Highlights

Floral timing is a carefully regulated process, in which the plant determines the optimal moment to switch from the vegetative to reproductive phase
This study describes the development of a chemical genomics screening platform for the identification of flowering inducing compounds, and discusses the various parameters that were taken into account
Considerations and initial set‐up of the screening platform In this study, we aimed to develop a chemical genomics screening platform for the identification of compounds that can induce flowering in Arabidopsis

Summary

Introduction

Floral timing is a carefully regulated process, in which the plant determines the optimal moment to switch from the vegetative to reproductive phase. They have to carefully monitor their growing conditions to determine the optimal moment of flowering This floral timing is a precisely regulated process, in which the plant determines the best moment to switch from the vegetative to the reproductive phase and to produce its offspring in the form of seed. The advantage of using compounds over a genetics approach is their transient mode-of-action, circumventing potential problems with lethality and providing possibilities to get around genetic redundancy, in case a compound targets a set of redundantly acting proteins [7, 8] For this purpose, we set out to screen a large collection of compounds in the model plant Arabidopsis thaliana. Media and growth conditions for growing Arabidopsis in 96-well plates were optimized, and a suitable flowering marker gene was cloned and fused to the sensitive luciferase reporter

Objectives

Methods

Results

Conclusion