Metabolomics and Physiological Approach to Understand Allelopathic Effect of Horseradish Extract on Onion Root and Lettuce Seed as Model Organism.

Tyler Simpson,Kang-Mo Ku

doi:10.3390/plants10101992

Tyler Simpson, Kang-Mo Ku

Open Access

https://doi.org/10.3390/plants10101992

Copy DOI

Abstract

In the present study, we assessed the allelopathic effects of various concentrations (0%, 0.1%, 0.2%, and 0.3%) of horseradish root extract (HRE) on onion root. The average growth of onion root tips during the 0% HRE treatment (deionized water treatment) was 0.9 cm/day, which was the highest among the growth rates obtained with all HRE treatments. Moreover, the average growth during 0.3% HRE treatment was 0.1 cm/day. During cell cycle analysis, the mitotic phase fraction of the control (deionized water treatment) cells was 6.5% of all dividing cells, with this percentage being the highest among the values obtained for all treatment groups. In the control group, all cell cycle phases were identified; however, in the 0.1%, 0.2%, and 0.3% treatment groups, telophase was not identified. The ROS accumulation area of the onion root decreased, as the HRE treatment concentration increased. In the control root, the area of dead tissue was 0%; however, in the 0.1% and 0.2% HRE treatment roots, the ratio was 5% and 50%, respectively. These findings indicate that the allelopathic effect of HRE depends on the concentration of HRE applied to the onion root.

Highlights

Our results confirm the allelopathic effect of horseradish root extract (HRE) on onion root and shows that this effect was dependent on the concentration of HRE
The average growth of onion root tips during 0.1% and 0.2% HRE treatments was 0.48 and 0.36 cm/day, respectively, and differed significantly from the growth rate obtained with the 0% HRE treatment (p < 0.05)
Allelopathy is a natural defense of plants against external threats; by studying allelopathy, it is possible to identify allelochemicals that may be used to produce growth regulators and natural herbicides for sustainable agriculture [42]

Summary

Introduction

Glucosinolate hydrolysis products have potential uses as medical and agricultural agents These compounds are known to exhibit anticarcinogenic effects against bladder, breast, colon, lung, stomach, and liver cancers in animal models [4]. We examined the allelopathic effects of horseradish extract (HRE), including the effects of glucosinolate and its derivatives, at the cellular level on onion (Allium cepa) root growth. We tried to clarify the effects of the HRE extract on plant cells using the onion by measuring the root length, observing the cell cycle, and evaluating the degree of reactive oxygen species (ROS) accumulation as well as metabolite changes during lettuce seed germination

Onion Root Growth after Treatment with Various Concentrations of HRE

Lettuce Root and Root Hair Measurement

Primary Metabolite Extraction and Analysis

Statistical Analysis

Conclusions